Show More
@@ -1,136 +1,136 b'' | |||
|
1 | 1 | .. _configuring_ipython: |
|
2 | 2 | |
|
3 | 3 | =========================================================== |
|
4 | 4 | Configuring the :command:`ipython` command line application |
|
5 | 5 | =========================================================== |
|
6 | 6 | |
|
7 | 7 | This section contains information about how to configure the |
|
8 | 8 | :command:`ipython` command line application. See the :ref:`configuration |
|
9 | 9 | overview <config_overview>` for a more general description of the |
|
10 | 10 | configuration system and configuration file format. |
|
11 | 11 | |
|
12 | 12 | The default configuration file for the :command:`ipython` command line application |
|
13 | 13 | is :file:`ipython_config.py`. By setting the attributes in this file, you |
|
14 | 14 | can configure the application. A sample is provided in |
|
15 | 15 | :mod:`IPython.config.default.ipython_config`. Simply copy this file to your |
|
16 | 16 | :ref:`IPython directory <ipython_dir>` to start using it. |
|
17 | 17 | |
|
18 | 18 | Most configuration attributes that this file accepts are associated with |
|
19 | 19 | classes that are subclasses of :class:`~IPython.core.component.Component`. |
|
20 | 20 | |
|
21 | 21 | A few configuration attributes are not associated with a particular |
|
22 | 22 | :class:`~IPython.core.component.Component` subclass. These are application |
|
23 | 23 | wide configuration attributes and are stored in the ``Global`` |
|
24 | 24 | sub-configuration section. We begin with a description of these |
|
25 | 25 | attributes. |
|
26 | 26 | |
|
27 | 27 | Global configuration |
|
28 | 28 | ==================== |
|
29 | 29 | |
|
30 | 30 | Assuming that your configuration file has the following at the top:: |
|
31 | 31 | |
|
32 | 32 | c = get_config() |
|
33 | 33 | |
|
34 | 34 | the following attributes can be set in the ``Global`` section. |
|
35 | 35 | |
|
36 |
:attr:`c. |
|
|
36 | :attr:`c.IPythonApp.display_banner` | |
|
37 | 37 | A boolean that determined if the banner is printer when :command:`ipython` |
|
38 | 38 | is started. |
|
39 | 39 | |
|
40 |
:attr:`c. |
|
|
40 | :attr:`c.IPythonApp.classic` | |
|
41 | 41 | A boolean that determines if IPython starts in "classic" mode. In this |
|
42 | 42 | mode, the prompts and everything mimic that of the normal :command:`python` |
|
43 | 43 | shell |
|
44 | 44 | |
|
45 |
:attr:`c. |
|
|
45 | :attr:`c.IPythonApp.nosep` | |
|
46 | 46 | A boolean that determines if there should be no blank lines between |
|
47 | 47 | prompts. |
|
48 | 48 | |
|
49 |
:attr:`c. |
|
|
49 | :attr:`c.IPythonApp.log_level` | |
|
50 | 50 | An integer that sets the detail of the logging level during the startup |
|
51 | 51 | of :command:`ipython`. The default is 30 and the possible values are |
|
52 | 52 | (0, 10, 20, 30, 40, 50). Higher is quieter and lower is more verbose. |
|
53 | 53 | |
|
54 |
:attr:`c. |
|
|
54 | :attr:`c.IPythonApp.extensions` | |
|
55 | 55 | A list of strings, each of which is an importable IPython extension. An |
|
56 | 56 | IPython extension is a regular Python module or package that has a |
|
57 | 57 | :func:`load_ipython_extension(ip)` method. This method gets called when |
|
58 | 58 | the extension is loaded with the currently running |
|
59 | 59 | :class:`~IPython.core.iplib.InteractiveShell` as its only argument. You |
|
60 | 60 | can put your extensions anywhere they can be imported but we add the |
|
61 | 61 | :file:`extensions` subdirectory of the ipython directory to ``sys.path`` |
|
62 | 62 | during extension loading, so you can put them there as well. Extensions |
|
63 | 63 | are not executed in the user's interactive namespace and they must be pure |
|
64 | 64 | Python code. Extensions are the recommended way of customizing |
|
65 | 65 | :command:`ipython`. Extensions can provide an |
|
66 | 66 | :func:`unload_ipython_extension` that will be called when the extension is |
|
67 | 67 | unloaded. |
|
68 | 68 | |
|
69 |
:attr:`c. |
|
|
69 | :attr:`c.IPythonApp.exec_lines` | |
|
70 | 70 | A list of strings, each of which is Python code that is run in the user's |
|
71 | 71 | namespace after IPython start. These lines can contain full IPython syntax |
|
72 | 72 | with magics, etc. |
|
73 | 73 | |
|
74 |
:attr:`c. |
|
|
74 | :attr:`c.IPythonApp.exec_files` | |
|
75 | 75 | A list of strings, each of which is the full pathname of a ``.py`` or |
|
76 | 76 | ``.ipy`` file that will be executed as IPython starts. These files are run |
|
77 | 77 | in IPython in the user's namespace. Files with a ``.py`` extension need to |
|
78 | 78 | be pure Python. Files with a ``.ipy`` extension can have custom IPython |
|
79 | 79 | syntax (magics, etc.). These files need to be in the cwd, the ipythondir |
|
80 | 80 | or be absolute paths. |
|
81 | 81 | |
|
82 | 82 | Classes that can be configured |
|
83 | 83 | ============================== |
|
84 | 84 | |
|
85 | 85 | The following classes can also be configured in the configuration file for |
|
86 | 86 | :command:`ipython`: |
|
87 | 87 | |
|
88 | 88 | * :class:`~IPython.core.iplib.InteractiveShell` |
|
89 | 89 | |
|
90 | 90 | * :class:`~IPython.core.prefilter.PrefilterManager` |
|
91 | 91 | |
|
92 | 92 | * :class:`~IPython.core.alias.AliasManager` |
|
93 | 93 | |
|
94 | 94 | To see which attributes of these classes are configurable, please see the |
|
95 | 95 | source code for these classes, the class docstrings or the sample |
|
96 | 96 | configuration file :mod:`IPython.config.default.ipython_config`. |
|
97 | 97 | |
|
98 | 98 | Example |
|
99 | 99 | ======= |
|
100 | 100 | |
|
101 | 101 | For those who want to get a quick start, here is a sample |
|
102 | 102 | :file:`ipython_config.py` that sets some of the common configuration |
|
103 | 103 | attributes:: |
|
104 | 104 | |
|
105 | 105 | # sample ipython_config.py |
|
106 | 106 | c = get_config() |
|
107 | 107 | |
|
108 |
c. |
|
|
109 |
c. |
|
|
110 |
c. |
|
|
108 | c.IPythonApp.display_banner = True | |
|
109 | c.IPythonApp.log_level = 20 | |
|
110 | c.IPythonApp.extensions = [ | |
|
111 | 111 | 'myextension' |
|
112 | 112 | ] |
|
113 |
c. |
|
|
113 | c.IPythonApp.exec_lines = [ | |
|
114 | 114 | 'import numpy', |
|
115 | 115 | 'import scipy' |
|
116 | 116 | ] |
|
117 |
c. |
|
|
117 | c.IPythonApp.exec_files = [ | |
|
118 | 118 | 'mycode.py', |
|
119 | 119 | 'fancy.ipy' |
|
120 | 120 | ] |
|
121 | 121 | c.InteractiveShell.autoindent = True |
|
122 | 122 | c.InteractiveShell.colors = 'LightBG' |
|
123 | 123 | c.InteractiveShell.confirm_exit = False |
|
124 | 124 | c.InteractiveShell.deep_reload = True |
|
125 | 125 | c.InteractiveShell.editor = 'nano' |
|
126 | 126 | c.InteractiveShell.prompt_in1 = 'In [\#]: ' |
|
127 | 127 | c.InteractiveShell.prompt_in2 = ' .\D.: ' |
|
128 | 128 | c.InteractiveShell.prompt_out = 'Out[\#]: ' |
|
129 | 129 | c.InteractiveShell.prompts_pad_left = True |
|
130 | 130 | c.InteractiveShell.xmode = 'Context' |
|
131 | 131 | |
|
132 | 132 | c.PrefilterManager.multi_line_specials = True |
|
133 | 133 | |
|
134 | 134 | c.AliasManager.user_aliases = [ |
|
135 | 135 | ('la', 'ls -al') |
|
136 | 136 | ] |
@@ -1,342 +1,342 b'' | |||
|
1 | 1 | .. _config_overview: |
|
2 | 2 | |
|
3 | 3 | ============================================ |
|
4 | 4 | Overview of the IPython configuration system |
|
5 | 5 | ============================================ |
|
6 | 6 | |
|
7 | 7 | This section describes the IPython configuration system. Starting with version |
|
8 | 8 | 0.11, IPython has a completely new configuration system that is quite |
|
9 | 9 | different from the older :file:`ipythonrc` or :file:`ipy_user_conf.py` |
|
10 | 10 | approaches. The new configuration system was designed from scratch to address |
|
11 | 11 | the particular configuration needs of IPython. While there are many |
|
12 | 12 | other excellent configuration systems out there, we found that none of them |
|
13 | 13 | met our requirements. |
|
14 | 14 | |
|
15 | 15 | .. warning:: |
|
16 | 16 | |
|
17 | 17 | If you are upgrading to version 0.11 of IPython, you will need to migrate |
|
18 | 18 | your old :file:`ipythonrc` or :file:`ipy_user_conf.py` configuration files |
|
19 | 19 | to the new system. Read on for information on how to do this. |
|
20 | 20 | |
|
21 | 21 | The discussion that follows is focused on teaching user's how to configure |
|
22 | 22 | IPython to their liking. Developer's who want to know more about how they |
|
23 | 23 | can enable their objects to take advantage of the configuration system |
|
24 | 24 | should consult our :ref:`developer guide <developer_guide>` |
|
25 | 25 | |
|
26 | 26 | The main concepts |
|
27 | 27 | ================= |
|
28 | 28 | |
|
29 | 29 | There are a number of abstractions that the IPython configuration system uses. |
|
30 | 30 | Each of these abstractions is represented by a Python class. |
|
31 | 31 | |
|
32 | 32 | Configuration object: :class:`~IPython.config.loader.Config` |
|
33 | 33 | A configuration object is a simple dictionary-like class that holds |
|
34 | 34 | configuration attributes and sub-configuration objects. These classes |
|
35 | 35 | support dotted attribute style access (``Foo.bar``) in addition to the |
|
36 | 36 | regular dictionary style access (``Foo['bar']``). Configuration objects |
|
37 | 37 | are smart. They know how to merge themselves with other configuration |
|
38 | 38 | objects and they automatically create sub-configuration objects. |
|
39 | 39 | |
|
40 | 40 | Application: :class:`~IPython.core.application.Application` |
|
41 | 41 | An application is a process that does a specific job. The most obvious |
|
42 | 42 | application is the :command:`ipython` command line program. Each |
|
43 | 43 | application reads a *single* configuration file and command line options |
|
44 | 44 | and then produces a master configuration object for the application. This |
|
45 | 45 | configuration object is then passed to the configurable objects that the |
|
46 | 46 | application creates. These configurable objects implement the actual logic |
|
47 | 47 | of the application and know how to configure themselves given the |
|
48 | 48 | configuration object. |
|
49 | 49 | |
|
50 | 50 | Component: :class:`~IPython.config.configurable.Configurable` |
|
51 | 51 | A configurable is a regular Python class that serves as a base class for |
|
52 | 52 | all main classes in an application. The |
|
53 | 53 | :class:`~IPython.config.configurable.Configurable` base class is |
|
54 | 54 | lightweight and only does one things. |
|
55 | 55 | |
|
56 | 56 | This :class:`~IPython.config.configurable.Configurable` is a subclass |
|
57 | 57 | of :class:`~IPython.utils.traitlets.HasTraits` that knows how to configure |
|
58 | 58 | itself. Class level traits with the metadata ``config=True`` become |
|
59 | 59 | values that can be configured from the command line and configuration |
|
60 | 60 | files. |
|
61 | 61 | |
|
62 | 62 | Developers create :class:`~IPython.config.configurable.Configurable` |
|
63 | 63 | subclasses that implement all of the logic in the application. Each of |
|
64 | 64 | these subclasses has its own configuration information that controls how |
|
65 | 65 | instances are created. |
|
66 | 66 | |
|
67 | 67 | Having described these main concepts, we can now state the main idea in our |
|
68 | 68 | configuration system: *"configuration" allows the default values of class |
|
69 | 69 | attributes to be controlled on a class by class basis*. Thus all instances of |
|
70 | 70 | a given class are configured in the same way. Furthermore, if two instances |
|
71 | 71 | need to be configured differently, they need to be instances of two different |
|
72 | 72 | classes. While this model may seem a bit restrictive, we have found that it |
|
73 | 73 | expresses most things that need to be configured extremely well. However, it |
|
74 | 74 | is possible to create two instances of the same class that have different |
|
75 | 75 | trait values. This is done by overriding the configuration. |
|
76 | 76 | |
|
77 | 77 | Now, we show what our configuration objects and files look like. |
|
78 | 78 | |
|
79 | 79 | Configuration objects and files |
|
80 | 80 | =============================== |
|
81 | 81 | |
|
82 | 82 | A configuration file is simply a pure Python file that sets the attributes |
|
83 | 83 | of a global, pre-created configuration object. This configuration object is a |
|
84 | 84 | :class:`~IPython.config.loader.Config` instance. While in a configuration |
|
85 | 85 | file, to get a reference to this object, simply call the :func:`get_config` |
|
86 | 86 | function. We inject this function into the global namespace that the |
|
87 | 87 | configuration file is executed in. |
|
88 | 88 | |
|
89 | 89 | Here is an example of a super simple configuration file that does nothing:: |
|
90 | 90 | |
|
91 | 91 | c = get_config() |
|
92 | 92 | |
|
93 | 93 | Once you get a reference to the configuration object, you simply set |
|
94 | 94 | attributes on it. All you have to know is: |
|
95 | 95 | |
|
96 | 96 | * The name of each attribute. |
|
97 | 97 | * The type of each attribute. |
|
98 | 98 | |
|
99 | 99 | The answers to these two questions are provided by the various |
|
100 | 100 | :class:`~IPython.config.configurable.Configurable` subclasses that an |
|
101 | 101 | application uses. Let's look at how this would work for a simple component |
|
102 | 102 | subclass:: |
|
103 | 103 | |
|
104 | 104 | # Sample component that can be configured. |
|
105 | 105 | from IPython.config.configurable import Configurable |
|
106 | 106 | from IPython.utils.traitlets import Int, Float, Str, Bool |
|
107 | 107 | |
|
108 | 108 | class MyClass(Configurable): |
|
109 | 109 | name = Str('defaultname', config=True) |
|
110 | 110 | ranking = Int(0, config=True) |
|
111 | 111 | value = Float(99.0) |
|
112 | 112 | # The rest of the class implementation would go here.. |
|
113 | 113 | |
|
114 | 114 | In this example, we see that :class:`MyClass` has three attributes, two |
|
115 | 115 | of whom (``name``, ``ranking``) can be configured. All of the attributes |
|
116 | 116 | are given types and default values. If a :class:`MyClass` is instantiated, |
|
117 | 117 | but not configured, these default values will be used. But let's see how |
|
118 | 118 | to configure this class in a configuration file:: |
|
119 | 119 | |
|
120 | 120 | # Sample config file |
|
121 | 121 | c = get_config() |
|
122 | 122 | |
|
123 | 123 | c.MyClass.name = 'coolname' |
|
124 | 124 | c.MyClass.ranking = 10 |
|
125 | 125 | |
|
126 | 126 | After this configuration file is loaded, the values set in it will override |
|
127 | 127 | the class defaults anytime a :class:`MyClass` is created. Furthermore, |
|
128 | 128 | these attributes will be type checked and validated anytime they are set. |
|
129 | 129 | This type checking is handled by the :mod:`IPython.utils.traitlets` module, |
|
130 | 130 | which provides the :class:`Str`, :class:`Int` and :class:`Float` types. In |
|
131 | 131 | addition to these traitlets, the :mod:`IPython.utils.traitlets` provides |
|
132 | 132 | traitlets for a number of other types. |
|
133 | 133 | |
|
134 | 134 | .. note:: |
|
135 | 135 | |
|
136 | 136 | Underneath the hood, the :class:`Configurable` base class is a subclass of |
|
137 | 137 | :class:`IPython.utils.traitlets.HasTraits`. The |
|
138 | 138 | :mod:`IPython.utils.traitlets` module is a lightweight version of |
|
139 | 139 | :mod:`enthought.traits`. Our implementation is a pure Python subset |
|
140 | 140 | (mostly API compatible) of :mod:`enthought.traits` that does not have any |
|
141 | 141 | of the automatic GUI generation capabilities. Our plan is to achieve 100% |
|
142 | 142 | API compatibility to enable the actual :mod:`enthought.traits` to |
|
143 | 143 | eventually be used instead. Currently, we cannot use |
|
144 | 144 | :mod:`enthought.traits` as we are committed to the core of IPython being |
|
145 | 145 | pure Python. |
|
146 | 146 | |
|
147 | 147 | It should be very clear at this point what the naming convention is for |
|
148 | 148 | configuration attributes:: |
|
149 | 149 | |
|
150 | 150 | c.ClassName.attribute_name = attribute_value |
|
151 | 151 | |
|
152 | 152 | Here, ``ClassName`` is the name of the class whose configuration attribute you |
|
153 | 153 | want to set, ``attribute_name`` is the name of the attribute you want to set |
|
154 | 154 | and ``attribute_value`` the the value you want it to have. The ``ClassName`` |
|
155 | 155 | attribute of ``c`` is not the actual class, but instead is another |
|
156 | 156 | :class:`~IPython.config.loader.Config` instance. |
|
157 | 157 | |
|
158 | 158 | .. note:: |
|
159 | 159 | |
|
160 | 160 | The careful reader may wonder how the ``ClassName`` (``MyClass`` in |
|
161 | 161 | the above example) attribute of the configuration object ``c`` gets |
|
162 | 162 | created. These attributes are created on the fly by the |
|
163 | 163 | :class:`~IPython.config.loader.Config` instance, using a simple naming |
|
164 | 164 | convention. Any attribute of a :class:`~IPython.config.loader.Config` |
|
165 | 165 | instance whose name begins with an uppercase character is assumed to be a |
|
166 | 166 | sub-configuration and a new empty :class:`~IPython.config.loader.Config` |
|
167 | 167 | instance is dynamically created for that attribute. This allows deeply |
|
168 | 168 | hierarchical information created easily (``c.Foo.Bar.value``) on the fly. |
|
169 | 169 | |
|
170 | 170 | Configuration files inheritance |
|
171 | 171 | =============================== |
|
172 | 172 | |
|
173 | 173 | Let's say you want to have different configuration files for various purposes. |
|
174 | 174 | Our configuration system makes it easy for one configuration file to inherit |
|
175 | 175 | the information in another configuration file. The :func:`load_subconfig` |
|
176 | 176 | command can be used in a configuration file for this purpose. Here is a simple |
|
177 | 177 | example that loads all of the values from the file :file:`base_config.py`:: |
|
178 | 178 | |
|
179 | 179 | # base_config.py |
|
180 | 180 | c = get_config() |
|
181 | 181 | c.MyClass.name = 'coolname' |
|
182 | 182 | c.MyClass.ranking = 100 |
|
183 | 183 | |
|
184 | 184 | into the configuration file :file:`main_config.py`:: |
|
185 | 185 | |
|
186 | 186 | # main_config.py |
|
187 | 187 | c = get_config() |
|
188 | 188 | |
|
189 | 189 | # Load everything from base_config.py |
|
190 | 190 | load_subconfig('base_config.py') |
|
191 | 191 | |
|
192 | 192 | # Now override one of the values |
|
193 | 193 | c.MyClass.name = 'bettername' |
|
194 | 194 | |
|
195 | 195 | In a situation like this the :func:`load_subconfig` makes sure that the |
|
196 | 196 | search path for sub-configuration files is inherited from that of the parent. |
|
197 | 197 | Thus, you can typically put the two in the same directory and everything will |
|
198 | 198 | just work. |
|
199 | 199 | |
|
200 | 200 | Class based configuration inheritance |
|
201 | 201 | ===================================== |
|
202 | 202 | |
|
203 | 203 | There is another aspect of configuration where inheritance comes into play. |
|
204 | 204 | Sometimes, your classes will have an inheritance hierarchy that you want |
|
205 | 205 | to be reflected in the configuration system. Here is a simple example:: |
|
206 | 206 | |
|
207 | 207 | from IPython.config.configurable import Configurable |
|
208 | 208 | from IPython.utils.traitlets import Int, Float, Str, Bool |
|
209 | 209 | |
|
210 | 210 | class Foo(Configurable): |
|
211 | 211 | name = Str('fooname', config=True) |
|
212 | 212 | value = Float(100.0, config=True) |
|
213 | 213 | |
|
214 | 214 | class Bar(Foo): |
|
215 | 215 | name = Str('barname', config=True) |
|
216 | 216 | othervalue = Int(0, config=True) |
|
217 | 217 | |
|
218 | 218 | Now, we can create a configuration file to configure instances of :class:`Foo` |
|
219 | 219 | and :class:`Bar`:: |
|
220 | 220 | |
|
221 | 221 | # config file |
|
222 | 222 | c = get_config() |
|
223 | 223 | |
|
224 | 224 | c.Foo.name = 'bestname' |
|
225 | 225 | c.Bar.othervalue = 10 |
|
226 | 226 | |
|
227 | 227 | This class hierarchy and configuration file accomplishes the following: |
|
228 | 228 | |
|
229 | 229 | * The default value for :attr:`Foo.name` and :attr:`Bar.name` will be |
|
230 | 230 | 'bestname'. Because :class:`Bar` is a :class:`Foo` subclass it also |
|
231 | 231 | picks up the configuration information for :class:`Foo`. |
|
232 | 232 | * The default value for :attr:`Foo.value` and :attr:`Bar.value` will be |
|
233 | 233 | ``100.0``, which is the value specified as the class default. |
|
234 | 234 | * The default value for :attr:`Bar.othervalue` will be 10 as set in the |
|
235 | 235 | configuration file. Because :class:`Foo` is the parent of :class:`Bar` |
|
236 | 236 | it doesn't know anything about the :attr:`othervalue` attribute. |
|
237 | 237 | |
|
238 | 238 | |
|
239 | 239 | .. _ipython_dir: |
|
240 | 240 | |
|
241 | 241 | Configuration file location |
|
242 | 242 | =========================== |
|
243 | 243 | |
|
244 | 244 | So where should you put your configuration files? By default, all IPython |
|
245 | 245 | applications look in the so called "IPython directory". The location of |
|
246 | 246 | this directory is determined by the following algorithm: |
|
247 | 247 | |
|
248 |
* If the `` |
|
|
248 | * If the ``ipython_dir`` command line flag is given, its value is used. | |
|
249 | 249 | |
|
250 | 250 | * If not, the value returned by :func:`IPython.utils.path.get_ipython_dir` |
|
251 | 251 | is used. This function will first look at the :envvar:`IPYTHON_DIR` |
|
252 | 252 | environment variable and then default to a platform-specific default. |
|
253 | 253 | |
|
254 | 254 | On posix systems (Linux, Unix, etc.), IPython respects the ``$XDG_CONFIG_HOME`` |
|
255 | 255 | part of the `XDG Base Directory`_ specification. If ``$XDG_CONFIG_HOME`` is |
|
256 | 256 | defined and exists ( ``XDG_CONFIG_HOME`` has a default interpretation of |
|
257 | 257 | :file:`$HOME/.config`), then IPython's config directory will be located in |
|
258 | 258 | :file:`$XDG_CONFIG_HOME/ipython`. If users still have an IPython directory |
|
259 | 259 | in :file:`$HOME/.ipython`, then that will be used. in preference to the |
|
260 | 260 | system default. |
|
261 | 261 | |
|
262 | 262 | For most users, the default value will simply be something like |
|
263 | 263 | :file:`$HOME/.config/ipython` on Linux, or :file:`$HOME/.ipython` |
|
264 | 264 | elsewhere. |
|
265 | 265 | |
|
266 | 266 | Once the location of the IPython directory has been determined, you need to |
|
267 | 267 | know what filename to use for the configuration file. The basic idea is that |
|
268 | 268 | each application has its own default configuration filename. The default named |
|
269 | 269 | used by the :command:`ipython` command line program is |
|
270 |
:file:`ipython_config.py`. This value can be overriden by the `` |
|
|
270 | :file:`ipython_config.py`. This value can be overriden by the ``config_file`` | |
|
271 | 271 | command line flag. A sample :file:`ipython_config.py` file can be found |
|
272 | 272 | in :mod:`IPython.config.default.ipython_config.py`. Simple copy it to your |
|
273 | 273 | IPython directory to begin using it. |
|
274 | 274 | |
|
275 | 275 | .. _Profiles: |
|
276 | 276 | |
|
277 | 277 | Profiles |
|
278 | 278 | ======== |
|
279 | 279 | |
|
280 | 280 | A profile is simply a configuration file that follows a simple naming |
|
281 | 281 | convention and can be loaded using a simplified syntax. The idea is |
|
282 | 282 | that users often want to maintain a set of configuration files for different |
|
283 | 283 | purposes: one for doing numerical computing with NumPy and SciPy and |
|
284 | 284 | another for doing symbolic computing with SymPy. Profiles make it easy |
|
285 | 285 | to keep a separate configuration file for each of these purposes. |
|
286 | 286 | |
|
287 | 287 | Let's start by showing how a profile is used: |
|
288 | 288 | |
|
289 | 289 | .. code-block:: bash |
|
290 | 290 | |
|
291 |
$ ipython |
|
|
291 | $ ipython profile=sympy | |
|
292 | 292 | |
|
293 | 293 | This tells the :command:`ipython` command line program to get its |
|
294 | 294 | configuration from the "sympy" profile. The search path for profiles is the |
|
295 | 295 | same as that of regular configuration files. The only difference is that |
|
296 | 296 | profiles are named in a special way. In the case above, the "sympy" profile |
|
297 | 297 | would need to have the name :file:`ipython_config_sympy.py`. |
|
298 | 298 | |
|
299 |
The general pattern is this: simply add `` |
|
|
300 |
normal configuration file name. Then load the profile by adding |
|
|
301 | profilename`` to your command line options. | |
|
299 | The general pattern is this: simply add ``<profilename>`` to the end of the | |
|
300 | normal configuration file name. Then load the profile by adding | |
|
301 | ``profile=<profilename>`` to your command line options. | |
|
302 | 302 | |
|
303 | 303 | IPython ships with some sample profiles in :mod:`IPython.config.profile`. |
|
304 | 304 | Simply copy these to your IPython directory to begin using them. |
|
305 | 305 | |
|
306 | 306 | Design requirements |
|
307 | 307 | =================== |
|
308 | 308 | |
|
309 | 309 | Here are the main requirements we wanted our configuration system to have: |
|
310 | 310 | |
|
311 | 311 | * Support for hierarchical configuration information. |
|
312 | 312 | |
|
313 | 313 | * Full integration with command line option parsers. Often, you want to read |
|
314 | 314 | a configuration file, but then override some of the values with command line |
|
315 | 315 | options. Our configuration system automates this process and allows each |
|
316 | 316 | command line option to be linked to a particular attribute in the |
|
317 | 317 | configuration hierarchy that it will override. |
|
318 | 318 | |
|
319 | 319 | * Configuration files that are themselves valid Python code. This accomplishes |
|
320 | 320 | many things. First, it becomes possible to put logic in your configuration |
|
321 | 321 | files that sets attributes based on your operating system, network setup, |
|
322 | 322 | Python version, etc. Second, Python has a super simple syntax for accessing |
|
323 | 323 | hierarchical data structures, namely regular attribute access |
|
324 | 324 | (``Foo.Bar.Bam.name``). Third, using Python makes it easy for users to |
|
325 | 325 | import configuration attributes from one configuration file to another. |
|
326 | 326 | Forth, even though Python is dynamically typed, it does have types that can |
|
327 | 327 | be checked at runtime. Thus, a ``1`` in a config file is the integer '1', |
|
328 | 328 | while a ``'1'`` is a string. |
|
329 | 329 | |
|
330 | 330 | * A fully automated method for getting the configuration information to the |
|
331 | 331 | classes that need it at runtime. Writing code that walks a configuration |
|
332 | 332 | hierarchy to extract a particular attribute is painful. When you have |
|
333 | 333 | complex configuration information with hundreds of attributes, this makes |
|
334 | 334 | you want to cry. |
|
335 | 335 | |
|
336 | 336 | * Type checking and validation that doesn't require the entire configuration |
|
337 | 337 | hierarchy to be specified statically before runtime. Python is a very |
|
338 | 338 | dynamic language and you don't always know everything that needs to be |
|
339 | 339 | configured when a program starts. |
|
340 | 340 | |
|
341 | 341 | |
|
342 | 342 | .. _`XDG Base Directory`: http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html |
@@ -1,1578 +1,1579 b'' | |||
|
1 | 1 | ================= |
|
2 | 2 | IPython reference |
|
3 | 3 | ================= |
|
4 | 4 | |
|
5 | 5 | .. warning:: |
|
6 | 6 | |
|
7 | 7 | As of the 0.11 version of IPython, some of the features and APIs |
|
8 | 8 | described in this section have been deprecated or are broken. Our plan |
|
9 | 9 | is to continue to support these features, but they need to be updated |
|
10 | 10 | to take advantage of recent API changes. Furthermore, this section |
|
11 | 11 | of the documentation need to be updated to reflect all of these changes. |
|
12 | 12 | |
|
13 | 13 | .. _command_line_options: |
|
14 | 14 | |
|
15 | 15 | Command-line usage |
|
16 | 16 | ================== |
|
17 | 17 | |
|
18 | 18 | You start IPython with the command:: |
|
19 | 19 | |
|
20 | 20 | $ ipython [options] files |
|
21 | 21 | |
|
22 | 22 | If invoked with no options, it executes all the files listed in sequence |
|
23 | 23 | and drops you into the interpreter while still acknowledging any options |
|
24 |
you may have set in your ipython |
|
|
24 | you may have set in your ipython_config.py. This behavior is different from | |
|
25 | 25 | standard Python, which when called as python -i will only execute one |
|
26 | 26 | file and ignore your configuration setup. |
|
27 | 27 | |
|
28 | 28 | Please note that some of the configuration options are not available at |
|
29 | 29 | the command line, simply because they are not practical here. Look into |
|
30 | 30 | your ipythonrc configuration file for details on those. This file is typically |
|
31 | 31 | installed in the IPYTHON_DIR directory. For Linux |
|
32 | 32 | users, this will be $HOME/.config/ipython, and for other users it will be |
|
33 | 33 | $HOME/.ipython. For Windows users, $HOME resolves to C:\\Documents and |
|
34 | 34 | Settings\\YourUserName in most instances. |
|
35 | 35 | |
|
36 | 36 | |
|
37 | 37 | |
|
38 | 38 | |
|
39 | 39 | Special Threading Options |
|
40 | 40 | ------------------------- |
|
41 | 41 | |
|
42 | 42 | Previously IPython had command line options for controlling GUI event loop |
|
43 | 43 | integration (-gthread, -qthread, -q4thread, -wthread, -pylab). As of IPython |
|
44 |
version 0.11, these have been |
|
|
44 | version 0.11, these have been removed. Please see the new ``%gui`` | |
|
45 | 45 | magic command or :ref:`this section <gui_support>` for details on the new |
|
46 | interface. | |
|
46 | interface, or specify the gui at the commandline:: | |
|
47 | ||
|
48 | $ ipython gui=qt | |
|
49 | ||
|
47 | 50 | |
|
48 | 51 | Regular Options |
|
49 | 52 | --------------- |
|
50 | 53 | |
|
51 | 54 | After the above threading options have been given, regular options can |
|
52 | 55 | follow in any order. All options can be abbreviated to their shortest |
|
53 | 56 | non-ambiguous form and are case-sensitive. One or two dashes can be |
|
54 | 57 | used. Some options have an alternate short form, indicated after a ``|``. |
|
55 | 58 | |
|
56 | 59 | Most options can also be set from your ipythonrc configuration file. See |
|
57 | 60 | the provided example for more details on what the options do. Options |
|
58 | 61 | given at the command line override the values set in the ipythonrc file. |
|
59 | 62 | |
|
60 | 63 | All options with a [no] prepended can be specified in negated form |
|
61 | (-nooption instead of -option) to turn the feature off. | |
|
64 | (--no-option instead of --option) to turn the feature off. | |
|
62 | 65 | |
|
63 | -help print a help message and exit. | |
|
66 | -h, --help print a help message and exit. | |
|
64 | 67 | |
|
65 | -pylab | |
|
66 |
|
|
|
68 | --pylab, pylab=<name> | |
|
69 | See :ref:`Matplotlib support <matplotlib_support>` | |
|
67 | 70 | for more details. |
|
68 | 71 | |
|
69 |
|
|
|
72 | autocall=<val> | |
|
70 | 73 | Make IPython automatically call any callable object even if you |
|
71 | 74 | didn't type explicit parentheses. For example, 'str 43' becomes |
|
72 | 75 | 'str(43)' automatically. The value can be '0' to disable the feature, |
|
73 | 76 | '1' for smart autocall, where it is not applied if there are no more |
|
74 | 77 | arguments on the line, and '2' for full autocall, where all callable |
|
75 | 78 | objects are automatically called (even if no arguments are |
|
76 | 79 | present). The default is '1'. |
|
77 | 80 | |
|
78 | -[no]autoindent | |
|
81 | --[no-]autoindent | |
|
79 | 82 | Turn automatic indentation on/off. |
|
80 | 83 | |
|
81 | -[no]automagic | |
|
84 | --[no-]automagic | |
|
82 | 85 | make magic commands automatic (without needing their first character |
|
83 | 86 | to be %). Type %magic at the IPython prompt for more information. |
|
84 | 87 | |
|
85 | -[no]autoedit_syntax | |
|
88 | --[no-]autoedit_syntax | |
|
86 | 89 | When a syntax error occurs after editing a file, automatically |
|
87 | 90 | open the file to the trouble causing line for convenient |
|
88 | 91 | fixing. |
|
89 | 92 | |
|
90 | -[no]banner Print the initial information banner (default on). | |
|
93 | --[no-]banner Print the initial information banner (default on). | |
|
91 | 94 | |
|
92 |
|
|
|
95 | c=<command> | |
|
93 | 96 | execute the given command string. This is similar to the -c |
|
94 | 97 | option in the normal Python interpreter. |
|
95 | 98 | |
|
96 |
|
|
|
99 | cache_size=<n> | |
|
97 | 100 | size of the output cache (maximum number of entries to hold in |
|
98 | 101 | memory). The default is 1000, you can change it permanently in your |
|
99 | 102 | config file. Setting it to 0 completely disables the caching system, |
|
100 | 103 | and the minimum value accepted is 20 (if you provide a value less than |
|
101 | 104 | 20, it is reset to 0 and a warning is issued) This limit is defined |
|
102 | 105 | because otherwise you'll spend more time re-flushing a too small cache |
|
103 | 106 | than working. |
|
104 | 107 | |
|
105 |
-classic |
|
|
108 | --classic | |
|
106 | 109 | Gives IPython a similar feel to the classic Python |
|
107 | 110 | prompt. |
|
108 | 111 | |
|
109 |
|
|
|
112 | colors=<scheme> | |
|
110 | 113 | Color scheme for prompts and exception reporting. Currently |
|
111 | 114 | implemented: NoColor, Linux and LightBG. |
|
112 | 115 | |
|
113 | -[no]color_info | |
|
116 | --[no-]color_info | |
|
114 | 117 | IPython can display information about objects via a set of functions, |
|
115 | 118 | and optionally can use colors for this, syntax highlighting source |
|
116 | 119 | code and various other elements. However, because this information is |
|
117 | 120 | passed through a pager (like 'less') and many pagers get confused with |
|
118 | 121 | color codes, this option is off by default. You can test it and turn |
|
119 | 122 | it on permanently in your ipythonrc file if it works for you. As a |
|
120 | 123 | reference, the 'less' pager supplied with Mandrake 8.2 works ok, but |
|
121 | 124 | that in RedHat 7.2 doesn't. |
|
122 | 125 | |
|
123 | 126 | Test it and turn it on permanently if it works with your |
|
124 | 127 | system. The magic function %color_info allows you to toggle this |
|
125 | 128 | interactively for testing. |
|
126 | 129 | |
|
127 | -[no]debug | |
|
130 | --[no-]debug | |
|
128 | 131 | Show information about the loading process. Very useful to pin down |
|
129 | 132 | problems with your configuration files or to get details about |
|
130 | 133 | session restores. |
|
131 | 134 | |
|
132 | -[no]deep_reload: | |
|
135 | --[no-]deep_reload: | |
|
133 | 136 | IPython can use the deep_reload module which reloads changes in |
|
134 | 137 | modules recursively (it replaces the reload() function, so you don't |
|
135 | 138 | need to change anything to use it). deep_reload() forces a full |
|
136 | 139 | reload of modules whose code may have changed, which the default |
|
137 | 140 | reload() function does not. |
|
138 | 141 | |
|
139 | 142 | When deep_reload is off, IPython will use the normal reload(), |
|
140 | 143 | but deep_reload will still be available as dreload(). This |
|
141 | 144 | feature is off by default [which means that you have both |
|
142 | 145 | normal reload() and dreload()]. |
|
143 | 146 | |
|
144 |
|
|
|
147 | editor=<name> | |
|
145 | 148 | Which editor to use with the %edit command. By default, |
|
146 | 149 | IPython will honor your EDITOR environment variable (if not |
|
147 | 150 | set, vi is the Unix default and notepad the Windows one). |
|
148 | 151 | Since this editor is invoked on the fly by IPython and is |
|
149 | 152 | meant for editing small code snippets, you may want to use a |
|
150 | 153 | small, lightweight editor here (in case your default EDITOR is |
|
151 | 154 | something like Emacs). |
|
152 | 155 | |
|
153 |
|
|
|
156 | ipython_dir=<name> | |
|
154 | 157 | name of your IPython configuration directory IPYTHON_DIR. This |
|
155 | 158 | can also be specified through the environment variable |
|
156 | 159 | IPYTHON_DIR. |
|
157 | 160 | |
|
158 | 161 | -log, l |
|
159 | 162 | generate a log file of all input. The file is named |
|
160 | 163 | ipython_log.py in your current directory (which prevents logs |
|
161 | 164 | from multiple IPython sessions from trampling each other). You |
|
162 | 165 | can use this to later restore a session by loading your |
|
163 | 166 | logfile as a file to be executed with option -logplay (see |
|
164 | 167 | below). |
|
165 | 168 | |
|
166 | 169 | -logfile, lf <name> specify the name of your logfile. |
|
167 | 170 | |
|
168 | 171 | -logplay, lp <name> |
|
169 | 172 | |
|
170 | 173 | you can replay a previous log. For restoring a session as close as |
|
171 | 174 | possible to the state you left it in, use this option (don't just run |
|
172 | 175 | the logfile). With -logplay, IPython will try to reconstruct the |
|
173 | 176 | previous working environment in full, not just execute the commands in |
|
174 | 177 | the logfile. |
|
175 | 178 | |
|
176 | 179 | When a session is restored, logging is automatically turned on |
|
177 | 180 | again with the name of the logfile it was invoked with (it is |
|
178 | 181 | read from the log header). So once you've turned logging on for |
|
179 | 182 | a session, you can quit IPython and reload it as many times as |
|
180 | 183 | you want and it will continue to log its history and restore |
|
181 | 184 | from the beginning every time. |
|
182 | 185 | |
|
183 | 186 | Caveats: there are limitations in this option. The history |
|
184 | 187 | variables _i*,_* and _dh don't get restored properly. In the |
|
185 | 188 | future we will try to implement full session saving by writing |
|
186 | 189 | and retrieving a 'snapshot' of the memory state of IPython. But |
|
187 | 190 | our first attempts failed because of inherent limitations of |
|
188 | 191 | Python's Pickle module, so this may have to wait. |
|
189 | 192 | |
|
190 | -[no]messages | |
|
193 | --[no-]messages | |
|
191 | 194 | Print messages which IPython collects about its startup |
|
192 | 195 | process (default on). |
|
193 | 196 | |
|
194 | -[no]pdb | |
|
197 | --[no-]pdb | |
|
195 | 198 | Automatically call the pdb debugger after every uncaught |
|
196 | 199 | exception. If you are used to debugging using pdb, this puts |
|
197 | 200 | you automatically inside of it after any call (either in |
|
198 | 201 | IPython or in code called by it) which triggers an exception |
|
199 | 202 | which goes uncaught. |
|
200 | 203 | |
|
201 | -pydb | |
|
204 | --pydb | |
|
202 | 205 | Makes IPython use the third party "pydb" package as debugger, |
|
203 | 206 | instead of pdb. Requires that pydb is installed. |
|
204 | 207 | |
|
205 | -[no]pprint | |
|
208 | --[no-]pprint | |
|
206 | 209 | ipython can optionally use the pprint (pretty printer) module |
|
207 | 210 | for displaying results. pprint tends to give a nicer display |
|
208 | 211 | of nested data structures. If you like it, you can turn it on |
|
209 | 212 | permanently in your config file (default off). |
|
210 | 213 | |
|
211 |
|
|
|
214 | profile=<name> | |
|
212 | 215 | |
|
213 | 216 | assume that your config file is ipythonrc-<name> or |
|
214 | 217 | ipy_profile_<name>.py (looks in current dir first, then in |
|
215 | 218 | IPYTHON_DIR). This is a quick way to keep and load multiple |
|
216 | 219 | config files for different tasks, especially if you use the |
|
217 | 220 | include option of config files. You can keep a basic |
|
218 | 221 | IPYTHON_DIR/ipythonrc file and then have other 'profiles' which |
|
219 | 222 | include this one and load extra things for particular |
|
220 | 223 | tasks. For example: |
|
221 | 224 | |
|
222 | 225 | 1. $IPYTHON_DIR/ipythonrc : load basic things you always want. |
|
223 | 226 | 2. $IPYTHON_DIR/ipythonrc-math : load (1) and basic math-related modules. |
|
224 | 227 | 3. $IPYTHON_DIR/ipythonrc-numeric : load (1) and Numeric and plotting modules. |
|
225 | 228 | |
|
226 | 229 | Since it is possible to create an endless loop by having |
|
227 | 230 | circular file inclusions, IPython will stop if it reaches 15 |
|
228 | 231 | recursive inclusions. |
|
229 | 232 | |
|
230 |
|
|
|
233 | pi1=<string> | |
|
231 | 234 | |
|
232 | 235 | Specify the string used for input prompts. Note that if you are using |
|
233 | 236 | numbered prompts, the number is represented with a '\#' in the |
|
234 | 237 | string. Don't forget to quote strings with spaces embedded in |
|
235 | 238 | them. Default: 'In [\#]:'. The :ref:`prompts section <prompts>` |
|
236 | 239 | discusses in detail all the available escapes to customize your |
|
237 | 240 | prompts. |
|
238 | 241 | |
|
239 |
|
|
|
242 | pi2=<string> | |
|
240 | 243 | Similar to the previous option, but used for the continuation |
|
241 | 244 | prompts. The special sequence '\D' is similar to '\#', but |
|
242 | 245 | with all digits replaced dots (so you can have your |
|
243 | 246 | continuation prompt aligned with your input prompt). Default: |
|
244 | 247 | ' .\D.:' (note three spaces at the start for alignment with |
|
245 | 248 | 'In [\#]'). |
|
246 | 249 | |
|
247 |
|
|
|
250 | po=<string> | |
|
248 | 251 | String used for output prompts, also uses numbers like |
|
249 | 252 | prompt_in1. Default: 'Out[\#]:' |
|
250 | 253 | |
|
251 | -quick start in bare bones mode (no config file loaded). | |
|
254 | --quick | |
|
255 | start in bare bones mode (no config file loaded). | |
|
252 | 256 | |
|
253 |
|
|
|
257 | config_file=<name> | |
|
254 | 258 | name of your IPython resource configuration file. Normally |
|
255 |
IPython loads ipython |
|
|
256 |
IPYTHON_DIR/ |
|
|
259 | IPython loads ipython_config.py (from current directory) or | |
|
260 | IPYTHON_DIR/profile_default. | |
|
257 | 261 | |
|
258 | 262 | If the loading of your config file fails, IPython starts with |
|
259 | 263 | a bare bones configuration (no modules loaded at all). |
|
260 | 264 | |
|
261 | -[no]readline | |
|
265 | --[no-]readline | |
|
262 | 266 | use the readline library, which is needed to support name |
|
263 | 267 | completion and command history, among other things. It is |
|
264 | 268 | enabled by default, but may cause problems for users of |
|
265 | 269 | X/Emacs in Python comint or shell buffers. |
|
266 | 270 | |
|
267 | 271 | Note that X/Emacs 'eterm' buffers (opened with M-x term) support |
|
268 | 272 | IPython's readline and syntax coloring fine, only 'emacs' (M-x |
|
269 | 273 | shell and C-c !) buffers do not. |
|
270 | 274 | |
|
271 | -screen_length, sl <n> | |
|
275 | sl=<n> | |
|
272 | 276 | number of lines of your screen. This is used to control |
|
273 | 277 | printing of very long strings. Strings longer than this number |
|
274 | 278 | of lines will be sent through a pager instead of directly |
|
275 | 279 | printed. |
|
276 | 280 | |
|
277 | 281 | The default value for this is 0, which means IPython will |
|
278 | 282 | auto-detect your screen size every time it needs to print certain |
|
279 | 283 | potentially long strings (this doesn't change the behavior of the |
|
280 | 284 | 'print' keyword, it's only triggered internally). If for some |
|
281 | 285 | reason this isn't working well (it needs curses support), specify |
|
282 | 286 | it yourself. Otherwise don't change the default. |
|
283 | 287 | |
|
284 |
|
|
|
288 | si=<string> | |
|
285 | 289 | |
|
286 | 290 | separator before input prompts. |
|
287 | 291 | Default: '\n' |
|
288 | 292 | |
|
289 |
|
|
|
293 | so=<string> | |
|
290 | 294 | separator before output prompts. |
|
291 | 295 | Default: nothing. |
|
292 | 296 | |
|
293 | -separate_out2, so2 | |
|
297 | so2=<string> | |
|
294 | 298 | separator after output prompts. |
|
295 | 299 | Default: nothing. |
|
296 | 300 | For these three options, use the value 0 to specify no separator. |
|
297 | 301 | |
|
298 |
-nosep |
|
|
302 | --nosep | |
|
299 | 303 | shorthand for '-SeparateIn 0 -SeparateOut 0 -SeparateOut2 |
|
300 | 304 | 0'. Simply removes all input/output separators. |
|
301 | 305 | |
|
302 | -upgrade | |
|
303 |
allows you to |
|
|
306 | --init | |
|
307 | allows you to initialize your IPYTHON_DIR configuration when you | |
|
304 | 308 | install a new version of IPython. Since new versions may |
|
305 | 309 | include new command line options or example files, this copies |
|
306 |
updated |
|
|
310 | updated config files. However, it backs up (with a | |
|
307 | 311 | .old extension) all files which it overwrites so that you can |
|
308 | 312 | merge back any customizations you might have in your personal |
|
309 | 313 | files. Note that you should probably use %upgrade instead, |
|
310 | 314 | it's a safer alternative. |
|
311 | 315 | |
|
312 | 316 | |
|
313 |
- |
|
|
314 | ||
|
315 | -wxversion <string> | |
|
316 | Deprecated. | |
|
317 | --version print version information and exit. | |
|
317 | 318 | |
|
318 |
|
|
|
319 | xmode=<modename> | |
|
319 | 320 | |
|
320 | 321 | Mode for exception reporting. |
|
321 | 322 | |
|
322 | 323 | Valid modes: Plain, Context and Verbose. |
|
323 | 324 | |
|
324 | 325 | * Plain: similar to python's normal traceback printing. |
|
325 | 326 | * Context: prints 5 lines of context source code around each |
|
326 | 327 | line in the traceback. |
|
327 | 328 | * Verbose: similar to Context, but additionally prints the |
|
328 | 329 | variables currently visible where the exception happened |
|
329 | 330 | (shortening their strings if too long). This can potentially be |
|
330 | 331 | very slow, if you happen to have a huge data structure whose |
|
331 | 332 | string representation is complex to compute. Your computer may |
|
332 | 333 | appear to freeze for a while with cpu usage at 100%. If this |
|
333 | 334 | occurs, you can cancel the traceback with Ctrl-C (maybe hitting it |
|
334 | 335 | more than once). |
|
335 | 336 | |
|
336 | 337 | Interactive use |
|
337 | 338 | =============== |
|
338 | 339 | |
|
339 | 340 | Warning: IPython relies on the existence of a global variable called |
|
340 | 341 | _ip which controls the shell itself. If you redefine _ip to anything, |
|
341 | 342 | bizarre behavior will quickly occur. |
|
342 | 343 | |
|
343 | 344 | Other than the above warning, IPython is meant to work as a drop-in |
|
344 | 345 | replacement for the standard interactive interpreter. As such, any code |
|
345 | 346 | which is valid python should execute normally under IPython (cases where |
|
346 | 347 | this is not true should be reported as bugs). It does, however, offer |
|
347 | 348 | many features which are not available at a standard python prompt. What |
|
348 | 349 | follows is a list of these. |
|
349 | 350 | |
|
350 | 351 | |
|
351 | 352 | Caution for Windows users |
|
352 | 353 | ------------------------- |
|
353 | 354 | |
|
354 | 355 | Windows, unfortunately, uses the '\' character as a path |
|
355 | 356 | separator. This is a terrible choice, because '\' also represents the |
|
356 | 357 | escape character in most modern programming languages, including |
|
357 | 358 | Python. For this reason, using '/' character is recommended if you |
|
358 | 359 | have problems with ``\``. However, in Windows commands '/' flags |
|
359 | 360 | options, so you can not use it for the root directory. This means that |
|
360 | 361 | paths beginning at the root must be typed in a contrived manner like: |
|
361 | 362 | ``%copy \opt/foo/bar.txt \tmp`` |
|
362 | 363 | |
|
363 | 364 | .. _magic: |
|
364 | 365 | |
|
365 | 366 | Magic command system |
|
366 | 367 | -------------------- |
|
367 | 368 | |
|
368 | 369 | IPython will treat any line whose first character is a % as a special |
|
369 | 370 | call to a 'magic' function. These allow you to control the behavior of |
|
370 | 371 | IPython itself, plus a lot of system-type features. They are all |
|
371 | 372 | prefixed with a % character, but parameters are given without |
|
372 | 373 | parentheses or quotes. |
|
373 | 374 | |
|
374 | 375 | Example: typing '%cd mydir' (without the quotes) changes you working |
|
375 | 376 | directory to 'mydir', if it exists. |
|
376 | 377 | |
|
377 | 378 | If you have 'automagic' enabled (in your ipythonrc file, via the command |
|
378 | 379 | line option -automagic or with the %automagic function), you don't need |
|
379 | 380 | to type in the % explicitly. IPython will scan its internal list of |
|
380 | 381 | magic functions and call one if it exists. With automagic on you can |
|
381 | 382 | then just type 'cd mydir' to go to directory 'mydir'. The automagic |
|
382 | 383 | system has the lowest possible precedence in name searches, so defining |
|
383 | 384 | an identifier with the same name as an existing magic function will |
|
384 | 385 | shadow it for automagic use. You can still access the shadowed magic |
|
385 | 386 | function by explicitly using the % character at the beginning of the line. |
|
386 | 387 | |
|
387 | 388 | An example (with automagic on) should clarify all this:: |
|
388 | 389 | |
|
389 | 390 | In [1]: cd ipython # %cd is called by automagic |
|
390 | 391 | |
|
391 | 392 | /home/fperez/ipython |
|
392 | 393 | |
|
393 | 394 | In [2]: cd=1 # now cd is just a variable |
|
394 | 395 | |
|
395 | 396 | In [3]: cd .. # and doesn't work as a function anymore |
|
396 | 397 | |
|
397 | 398 | ------------------------------ |
|
398 | 399 | |
|
399 | 400 | File "<console>", line 1 |
|
400 | 401 | |
|
401 | 402 | cd .. |
|
402 | 403 | |
|
403 | 404 | ^ |
|
404 | 405 | |
|
405 | 406 | SyntaxError: invalid syntax |
|
406 | 407 | |
|
407 | 408 | In [4]: %cd .. # but %cd always works |
|
408 | 409 | |
|
409 | 410 | /home/fperez |
|
410 | 411 | |
|
411 | 412 | In [5]: del cd # if you remove the cd variable |
|
412 | 413 | |
|
413 | 414 | In [6]: cd ipython # automagic can work again |
|
414 | 415 | |
|
415 | 416 | /home/fperez/ipython |
|
416 | 417 | |
|
417 | 418 | You can define your own magic functions to extend the system. The |
|
418 | 419 | following example defines a new magic command, %impall:: |
|
419 | 420 | |
|
420 | 421 | import IPython.ipapi |
|
421 | 422 | |
|
422 | 423 | ip = IPython.ipapi.get() |
|
423 | 424 | |
|
424 | 425 | def doimp(self, arg): |
|
425 | 426 | |
|
426 | 427 | ip = self.api |
|
427 | 428 | |
|
428 | 429 | ip.ex("import %s; reload(%s); from %s import *" % ( |
|
429 | 430 | |
|
430 | 431 | arg,arg,arg) |
|
431 | 432 | |
|
432 | 433 | ) |
|
433 | 434 | |
|
434 | 435 | ip.expose_magic('impall', doimp) |
|
435 | 436 | |
|
436 | 437 | You can also define your own aliased names for magic functions. In your |
|
437 | 438 | ipythonrc file, placing a line like:: |
|
438 | 439 | |
|
439 | 440 | execute __IP.magic_cl = __IP.magic_clear |
|
440 | 441 | |
|
441 | 442 | will define %cl as a new name for %clear. |
|
442 | 443 | |
|
443 | 444 | Type %magic for more information, including a list of all available |
|
444 | 445 | magic functions at any time and their docstrings. You can also type |
|
445 | 446 | %magic_function_name? (see sec. 6.4 <#sec:dyn-object-info> for |
|
446 | 447 | information on the '?' system) to get information about any particular |
|
447 | 448 | magic function you are interested in. |
|
448 | 449 | |
|
449 | 450 | The API documentation for the :mod:`IPython.Magic` module contains the full |
|
450 | 451 | docstrings of all currently available magic commands. |
|
451 | 452 | |
|
452 | 453 | |
|
453 | 454 | Access to the standard Python help |
|
454 | 455 | ---------------------------------- |
|
455 | 456 | |
|
456 | 457 | As of Python 2.1, a help system is available with access to object docstrings |
|
457 | 458 | and the Python manuals. Simply type 'help' (no quotes) to access it. You can |
|
458 | 459 | also type help(object) to obtain information about a given object, and |
|
459 | 460 | help('keyword') for information on a keyword. As noted :ref:`here |
|
460 | 461 | <accessing_help>`, you need to properly configure your environment variable |
|
461 | 462 | PYTHONDOCS for this feature to work correctly. |
|
462 | 463 | |
|
463 | 464 | .. _dynamic_object_info: |
|
464 | 465 | |
|
465 | 466 | Dynamic object information |
|
466 | 467 | -------------------------- |
|
467 | 468 | |
|
468 | 469 | Typing ?word or word? prints detailed information about an object. If |
|
469 | 470 | certain strings in the object are too long (docstrings, code, etc.) they |
|
470 | 471 | get snipped in the center for brevity. This system gives access variable |
|
471 | 472 | types and values, full source code for any object (if available), |
|
472 | 473 | function prototypes and other useful information. |
|
473 | 474 | |
|
474 | 475 | Typing ??word or word?? gives access to the full information without |
|
475 | 476 | snipping long strings. Long strings are sent to the screen through the |
|
476 | 477 | less pager if longer than the screen and printed otherwise. On systems |
|
477 | 478 | lacking the less command, IPython uses a very basic internal pager. |
|
478 | 479 | |
|
479 | 480 | The following magic functions are particularly useful for gathering |
|
480 | 481 | information about your working environment. You can get more details by |
|
481 | 482 | typing %magic or querying them individually (use %function_name? with or |
|
482 | 483 | without the %), this is just a summary: |
|
483 | 484 | |
|
484 | 485 | * **%pdoc <object>**: Print (or run through a pager if too long) the |
|
485 | 486 | docstring for an object. If the given object is a class, it will |
|
486 | 487 | print both the class and the constructor docstrings. |
|
487 | 488 | * **%pdef <object>**: Print the definition header for any callable |
|
488 | 489 | object. If the object is a class, print the constructor information. |
|
489 | 490 | * **%psource <object>**: Print (or run through a pager if too long) |
|
490 | 491 | the source code for an object. |
|
491 | 492 | * **%pfile <object>**: Show the entire source file where an object was |
|
492 | 493 | defined via a pager, opening it at the line where the object |
|
493 | 494 | definition begins. |
|
494 | 495 | * **%who/%whos**: These functions give information about identifiers |
|
495 | 496 | you have defined interactively (not things you loaded or defined |
|
496 | 497 | in your configuration files). %who just prints a list of |
|
497 | 498 | identifiers and %whos prints a table with some basic details about |
|
498 | 499 | each identifier. |
|
499 | 500 | |
|
500 | 501 | Note that the dynamic object information functions (?/??, %pdoc, %pfile, |
|
501 | 502 | %pdef, %psource) give you access to documentation even on things which |
|
502 | 503 | are not really defined as separate identifiers. Try for example typing |
|
503 | 504 | {}.get? or after doing import os, type os.path.abspath??. |
|
504 | 505 | |
|
505 | 506 | |
|
506 | 507 | .. _readline: |
|
507 | 508 | |
|
508 | 509 | Readline-based features |
|
509 | 510 | ----------------------- |
|
510 | 511 | |
|
511 | 512 | These features require the GNU readline library, so they won't work if |
|
512 | 513 | your Python installation lacks readline support. We will first describe |
|
513 | 514 | the default behavior IPython uses, and then how to change it to suit |
|
514 | 515 | your preferences. |
|
515 | 516 | |
|
516 | 517 | |
|
517 | 518 | Command line completion |
|
518 | 519 | +++++++++++++++++++++++ |
|
519 | 520 | |
|
520 | 521 | At any time, hitting TAB will complete any available python commands or |
|
521 | 522 | variable names, and show you a list of the possible completions if |
|
522 | 523 | there's no unambiguous one. It will also complete filenames in the |
|
523 | 524 | current directory if no python names match what you've typed so far. |
|
524 | 525 | |
|
525 | 526 | |
|
526 | 527 | Search command history |
|
527 | 528 | ++++++++++++++++++++++ |
|
528 | 529 | |
|
529 | 530 | IPython provides two ways for searching through previous input and thus |
|
530 | 531 | reduce the need for repetitive typing: |
|
531 | 532 | |
|
532 | 533 | 1. Start typing, and then use Ctrl-p (previous,up) and Ctrl-n |
|
533 | 534 | (next,down) to search through only the history items that match |
|
534 | 535 | what you've typed so far. If you use Ctrl-p/Ctrl-n at a blank |
|
535 | 536 | prompt, they just behave like normal arrow keys. |
|
536 | 537 | 2. Hit Ctrl-r: opens a search prompt. Begin typing and the system |
|
537 | 538 | searches your history for lines that contain what you've typed so |
|
538 | 539 | far, completing as much as it can. |
|
539 | 540 | |
|
540 | 541 | |
|
541 | 542 | Persistent command history across sessions |
|
542 | 543 | ++++++++++++++++++++++++++++++++++++++++++ |
|
543 | 544 | |
|
544 | 545 | IPython will save your input history when it leaves and reload it next |
|
545 | 546 | time you restart it. By default, the history file is named |
|
546 | 547 | $IPYTHON_DIR/history, but if you've loaded a named profile, |
|
547 | 548 | '-PROFILE_NAME' is appended to the name. This allows you to keep |
|
548 | 549 | separate histories related to various tasks: commands related to |
|
549 | 550 | numerical work will not be clobbered by a system shell history, for |
|
550 | 551 | example. |
|
551 | 552 | |
|
552 | 553 | |
|
553 | 554 | Autoindent |
|
554 | 555 | ++++++++++ |
|
555 | 556 | |
|
556 | 557 | IPython can recognize lines ending in ':' and indent the next line, |
|
557 | 558 | while also un-indenting automatically after 'raise' or 'return'. |
|
558 | 559 | |
|
559 | 560 | This feature uses the readline library, so it will honor your ~/.inputrc |
|
560 | 561 | configuration (or whatever file your INPUTRC variable points to). Adding |
|
561 | 562 | the following lines to your .inputrc file can make indenting/unindenting |
|
562 | 563 | more convenient (M-i indents, M-u unindents):: |
|
563 | 564 | |
|
564 | 565 | $if Python |
|
565 | 566 | "\M-i": " " |
|
566 | 567 | "\M-u": "\d\d\d\d" |
|
567 | 568 | $endif |
|
568 | 569 | |
|
569 | 570 | Note that there are 4 spaces between the quote marks after "M-i" above. |
|
570 | 571 | |
|
571 | 572 | Warning: this feature is ON by default, but it can cause problems with |
|
572 | 573 | the pasting of multi-line indented code (the pasted code gets |
|
573 | 574 | re-indented on each line). A magic function %autoindent allows you to |
|
574 | 575 | toggle it on/off at runtime. You can also disable it permanently on in |
|
575 | 576 | your ipythonrc file (set autoindent 0). |
|
576 | 577 | |
|
577 | 578 | |
|
578 | 579 | Customizing readline behavior |
|
579 | 580 | +++++++++++++++++++++++++++++ |
|
580 | 581 | |
|
581 | 582 | All these features are based on the GNU readline library, which has an |
|
582 | 583 | extremely customizable interface. Normally, readline is configured via a |
|
583 | 584 | file which defines the behavior of the library; the details of the |
|
584 | 585 | syntax for this can be found in the readline documentation available |
|
585 | 586 | with your system or on the Internet. IPython doesn't read this file (if |
|
586 | 587 | it exists) directly, but it does support passing to readline valid |
|
587 | 588 | options via a simple interface. In brief, you can customize readline by |
|
588 | 589 | setting the following options in your ipythonrc configuration file (note |
|
589 | 590 | that these options can not be specified at the command line): |
|
590 | 591 | |
|
591 | 592 | * **readline_parse_and_bind**: this option can appear as many times as |
|
592 | 593 | you want, each time defining a string to be executed via a |
|
593 | 594 | readline.parse_and_bind() command. The syntax for valid commands |
|
594 | 595 | of this kind can be found by reading the documentation for the GNU |
|
595 | 596 | readline library, as these commands are of the kind which readline |
|
596 | 597 | accepts in its configuration file. |
|
597 | 598 | * **readline_remove_delims**: a string of characters to be removed |
|
598 | 599 | from the default word-delimiters list used by readline, so that |
|
599 | 600 | completions may be performed on strings which contain them. Do not |
|
600 | 601 | change the default value unless you know what you're doing. |
|
601 | 602 | * **readline_omit__names**: when tab-completion is enabled, hitting |
|
602 | 603 | <tab> after a '.' in a name will complete all attributes of an |
|
603 | 604 | object, including all the special methods whose names include |
|
604 | 605 | double underscores (like __getitem__ or __class__). If you'd |
|
605 | 606 | rather not see these names by default, you can set this option to |
|
606 | 607 | 1. Note that even when this option is set, you can still see those |
|
607 | 608 | names by explicitly typing a _ after the period and hitting <tab>: |
|
608 | 609 | 'name._<tab>' will always complete attribute names starting with '_'. |
|
609 | 610 | |
|
610 | 611 | This option is off by default so that new users see all |
|
611 | 612 | attributes of any objects they are dealing with. |
|
612 | 613 | |
|
613 | 614 | You will find the default values along with a corresponding detailed |
|
614 | 615 | explanation in your ipythonrc file. |
|
615 | 616 | |
|
616 | 617 | |
|
617 | 618 | Session logging and restoring |
|
618 | 619 | ----------------------------- |
|
619 | 620 | |
|
620 | 621 | You can log all input from a session either by starting IPython with the |
|
621 | 622 | command line switches -log or -logfile (see :ref:`here <command_line_options>`) |
|
622 | 623 | or by activating the logging at any moment with the magic function %logstart. |
|
623 | 624 | |
|
624 | 625 | Log files can later be reloaded with the -logplay option and IPython |
|
625 | 626 | will attempt to 'replay' the log by executing all the lines in it, thus |
|
626 | 627 | restoring the state of a previous session. This feature is not quite |
|
627 | 628 | perfect, but can still be useful in many cases. |
|
628 | 629 | |
|
629 | 630 | The log files can also be used as a way to have a permanent record of |
|
630 | 631 | any code you wrote while experimenting. Log files are regular text files |
|
631 | 632 | which you can later open in your favorite text editor to extract code or |
|
632 | 633 | to 'clean them up' before using them to replay a session. |
|
633 | 634 | |
|
634 | 635 | The %logstart function for activating logging in mid-session is used as |
|
635 | 636 | follows: |
|
636 | 637 | |
|
637 | 638 | %logstart [log_name [log_mode]] |
|
638 | 639 | |
|
639 | 640 | If no name is given, it defaults to a file named 'log' in your |
|
640 | 641 | IPYTHON_DIR directory, in 'rotate' mode (see below). |
|
641 | 642 | |
|
642 | 643 | '%logstart name' saves to file 'name' in 'backup' mode. It saves your |
|
643 | 644 | history up to that point and then continues logging. |
|
644 | 645 | |
|
645 | 646 | %logstart takes a second optional parameter: logging mode. This can be |
|
646 | 647 | one of (note that the modes are given unquoted): |
|
647 | 648 | |
|
648 | 649 | * [over:] overwrite existing log_name. |
|
649 | 650 | * [backup:] rename (if exists) to log_name~ and start log_name. |
|
650 | 651 | * [append:] well, that says it. |
|
651 | 652 | * [rotate:] create rotating logs log_name.1~, log_name.2~, etc. |
|
652 | 653 | |
|
653 | 654 | The %logoff and %logon functions allow you to temporarily stop and |
|
654 | 655 | resume logging to a file which had previously been started with |
|
655 | 656 | %logstart. They will fail (with an explanation) if you try to use them |
|
656 | 657 | before logging has been started. |
|
657 | 658 | |
|
658 | 659 | .. _system_shell_access: |
|
659 | 660 | |
|
660 | 661 | System shell access |
|
661 | 662 | ------------------- |
|
662 | 663 | |
|
663 | 664 | Any input line beginning with a ! character is passed verbatim (minus |
|
664 | 665 | the !, of course) to the underlying operating system. For example, |
|
665 | 666 | typing !ls will run 'ls' in the current directory. |
|
666 | 667 | |
|
667 | 668 | Manual capture of command output |
|
668 | 669 | -------------------------------- |
|
669 | 670 | |
|
670 | 671 | If the input line begins with two exclamation marks, !!, the command is |
|
671 | 672 | executed but its output is captured and returned as a python list, split |
|
672 | 673 | on newlines. Any output sent by the subprocess to standard error is |
|
673 | 674 | printed separately, so that the resulting list only captures standard |
|
674 | 675 | output. The !! syntax is a shorthand for the %sx magic command. |
|
675 | 676 | |
|
676 | 677 | Finally, the %sc magic (short for 'shell capture') is similar to %sx, |
|
677 | 678 | but allowing more fine-grained control of the capture details, and |
|
678 | 679 | storing the result directly into a named variable. The direct use of |
|
679 | 680 | %sc is now deprecated, and you should ise the ``var = !cmd`` syntax |
|
680 | 681 | instead. |
|
681 | 682 | |
|
682 | 683 | IPython also allows you to expand the value of python variables when |
|
683 | 684 | making system calls. Any python variable or expression which you prepend |
|
684 | 685 | with $ will get expanded before the system call is made:: |
|
685 | 686 | |
|
686 | 687 | In [1]: pyvar='Hello world' |
|
687 | 688 | In [2]: !echo "A python variable: $pyvar" |
|
688 | 689 | A python variable: Hello world |
|
689 | 690 | |
|
690 | 691 | If you want the shell to actually see a literal $, you need to type it |
|
691 | 692 | twice:: |
|
692 | 693 | |
|
693 | 694 | In [3]: !echo "A system variable: $$HOME" |
|
694 | 695 | A system variable: /home/fperez |
|
695 | 696 | |
|
696 | 697 | You can pass arbitrary expressions, though you'll need to delimit them |
|
697 | 698 | with {} if there is ambiguity as to the extent of the expression:: |
|
698 | 699 | |
|
699 | 700 | In [5]: x=10 |
|
700 | 701 | In [6]: y=20 |
|
701 | 702 | In [13]: !echo $x+y |
|
702 | 703 | 10+y |
|
703 | 704 | In [7]: !echo ${x+y} |
|
704 | 705 | 30 |
|
705 | 706 | |
|
706 | 707 | Even object attributes can be expanded:: |
|
707 | 708 | |
|
708 | 709 | In [12]: !echo $sys.argv |
|
709 | 710 | [/home/fperez/usr/bin/ipython] |
|
710 | 711 | |
|
711 | 712 | |
|
712 | 713 | System command aliases |
|
713 | 714 | ---------------------- |
|
714 | 715 | |
|
715 | 716 | The %alias magic function and the alias option in the ipythonrc |
|
716 | 717 | configuration file allow you to define magic functions which are in fact |
|
717 | 718 | system shell commands. These aliases can have parameters. |
|
718 | 719 | |
|
719 | 720 | '%alias alias_name cmd' defines 'alias_name' as an alias for 'cmd' |
|
720 | 721 | |
|
721 | 722 | Then, typing '%alias_name params' will execute the system command 'cmd |
|
722 | 723 | params' (from your underlying operating system). |
|
723 | 724 | |
|
724 | 725 | You can also define aliases with parameters using %s specifiers (one per |
|
725 | 726 | parameter). The following example defines the %parts function as an |
|
726 | 727 | alias to the command 'echo first %s second %s' where each %s will be |
|
727 | 728 | replaced by a positional parameter to the call to %parts:: |
|
728 | 729 | |
|
729 | 730 | In [1]: alias parts echo first %s second %s |
|
730 | 731 | In [2]: %parts A B |
|
731 | 732 | first A second B |
|
732 | 733 | In [3]: %parts A |
|
733 | 734 | Incorrect number of arguments: 2 expected. |
|
734 | 735 | parts is an alias to: 'echo first %s second %s' |
|
735 | 736 | |
|
736 | 737 | If called with no parameters, %alias prints the table of currently |
|
737 | 738 | defined aliases. |
|
738 | 739 | |
|
739 | 740 | The %rehash/rehashx magics allow you to load your entire $PATH as |
|
740 | 741 | ipython aliases. See their respective docstrings (or sec. 6.2 |
|
741 | 742 | <#sec:magic> for further details). |
|
742 | 743 | |
|
743 | 744 | |
|
744 | 745 | .. _dreload: |
|
745 | 746 | |
|
746 | 747 | Recursive reload |
|
747 | 748 | ---------------- |
|
748 | 749 | |
|
749 | 750 | The dreload function does a recursive reload of a module: changes made |
|
750 | 751 | to the module since you imported will actually be available without |
|
751 | 752 | having to exit. |
|
752 | 753 | |
|
753 | 754 | |
|
754 | 755 | Verbose and colored exception traceback printouts |
|
755 | 756 | ------------------------------------------------- |
|
756 | 757 | |
|
757 | 758 | IPython provides the option to see very detailed exception tracebacks, |
|
758 | 759 | which can be especially useful when debugging large programs. You can |
|
759 | 760 | run any Python file with the %run function to benefit from these |
|
760 | 761 | detailed tracebacks. Furthermore, both normal and verbose tracebacks can |
|
761 | 762 | be colored (if your terminal supports it) which makes them much easier |
|
762 | 763 | to parse visually. |
|
763 | 764 | |
|
764 | 765 | See the magic xmode and colors functions for details (just type %magic). |
|
765 | 766 | |
|
766 | 767 | These features are basically a terminal version of Ka-Ping Yee's cgitb |
|
767 | 768 | module, now part of the standard Python library. |
|
768 | 769 | |
|
769 | 770 | |
|
770 | 771 | .. _input_caching: |
|
771 | 772 | |
|
772 | 773 | Input caching system |
|
773 | 774 | -------------------- |
|
774 | 775 | |
|
775 | 776 | IPython offers numbered prompts (In/Out) with input and output caching |
|
776 | 777 | (also referred to as 'input history'). All input is saved and can be |
|
777 | 778 | retrieved as variables (besides the usual arrow key recall), in |
|
778 | 779 | addition to the %rep magic command that brings a history entry |
|
779 | 780 | up for editing on the next command line. |
|
780 | 781 | |
|
781 | 782 | The following GLOBAL variables always exist (so don't overwrite them!): |
|
782 | 783 | _i: stores previous input. _ii: next previous. _iii: next-next previous. |
|
783 | 784 | _ih : a list of all input _ih[n] is the input from line n and this list |
|
784 | 785 | is aliased to the global variable In. If you overwrite In with a |
|
785 | 786 | variable of your own, you can remake the assignment to the internal list |
|
786 | 787 | with a simple 'In=_ih'. |
|
787 | 788 | |
|
788 | 789 | Additionally, global variables named _i<n> are dynamically created (<n> |
|
789 | 790 | being the prompt counter), such that |
|
790 | 791 | _i<n> == _ih[<n>] == In[<n>]. |
|
791 | 792 | |
|
792 | 793 | For example, what you typed at prompt 14 is available as _i14, _ih[14] |
|
793 | 794 | and In[14]. |
|
794 | 795 | |
|
795 | 796 | This allows you to easily cut and paste multi line interactive prompts |
|
796 | 797 | by printing them out: they print like a clean string, without prompt |
|
797 | 798 | characters. You can also manipulate them like regular variables (they |
|
798 | 799 | are strings), modify or exec them (typing 'exec _i9' will re-execute the |
|
799 | 800 | contents of input prompt 9, 'exec In[9:14]+In[18]' will re-execute lines |
|
800 | 801 | 9 through 13 and line 18). |
|
801 | 802 | |
|
802 | 803 | You can also re-execute multiple lines of input easily by using the |
|
803 | 804 | magic %macro function (which automates the process and allows |
|
804 | 805 | re-execution without having to type 'exec' every time). The macro system |
|
805 | 806 | also allows you to re-execute previous lines which include magic |
|
806 | 807 | function calls (which require special processing). Type %macro? or see |
|
807 | 808 | sec. 6.2 <#sec:magic> for more details on the macro system. |
|
808 | 809 | |
|
809 | 810 | A history function %hist allows you to see any part of your input |
|
810 | 811 | history by printing a range of the _i variables. |
|
811 | 812 | |
|
812 | 813 | You can also search ('grep') through your history by typing |
|
813 | 814 | '%hist -g somestring'. This also searches through the so called *shadow history*, |
|
814 | 815 | which remembers all the commands (apart from multiline code blocks) |
|
815 | 816 | you have ever entered. Handy for searching for svn/bzr URL's, IP adrresses |
|
816 | 817 | etc. You can bring shadow history entries listed by '%hist -g' up for editing |
|
817 | 818 | (or re-execution by just pressing ENTER) with %rep command. Shadow history |
|
818 | 819 | entries are not available as _iNUMBER variables, and they are identified by |
|
819 | 820 | the '0' prefix in %hist -g output. That is, history entry 12 is a normal |
|
820 | 821 | history entry, but 0231 is a shadow history entry. |
|
821 | 822 | |
|
822 | 823 | Shadow history was added because the readline history is inherently very |
|
823 | 824 | unsafe - if you have multiple IPython sessions open, the last session |
|
824 | 825 | to close will overwrite the history of previountly closed session. Likewise, |
|
825 | 826 | if a crash occurs, history is never saved, whereas shadow history entries |
|
826 | 827 | are added after entering every command (so a command executed |
|
827 | 828 | in another IPython session is immediately available in other IPython |
|
828 | 829 | sessions that are open). |
|
829 | 830 | |
|
830 | 831 | To conserve space, a command can exist in shadow history only once - it doesn't |
|
831 | 832 | make sense to store a common line like "cd .." a thousand times. The idea is |
|
832 | 833 | mainly to provide a reliable place where valuable, hard-to-remember commands can |
|
833 | 834 | always be retrieved, as opposed to providing an exact sequence of commands |
|
834 | 835 | you have entered in actual order. |
|
835 | 836 | |
|
836 | 837 | Because shadow history has all the commands you have ever executed, |
|
837 | 838 | time taken by %hist -g will increase oven time. If it ever starts to take |
|
838 | 839 | too long (or it ends up containing sensitive information like passwords), |
|
839 | 840 | clear the shadow history by `%clear shadow_nuke`. |
|
840 | 841 | |
|
841 | 842 | Time taken to add entries to shadow history should be negligible, but |
|
842 | 843 | in any case, if you start noticing performance degradation after using |
|
843 | 844 | IPython for a long time (or running a script that floods the shadow history!), |
|
844 | 845 | you can 'compress' the shadow history by executing |
|
845 | 846 | `%clear shadow_compress`. In practice, this should never be necessary |
|
846 | 847 | in normal use. |
|
847 | 848 | |
|
848 | 849 | .. _output_caching: |
|
849 | 850 | |
|
850 | 851 | Output caching system |
|
851 | 852 | --------------------- |
|
852 | 853 | |
|
853 | 854 | For output that is returned from actions, a system similar to the input |
|
854 | 855 | cache exists but using _ instead of _i. Only actions that produce a |
|
855 | 856 | result (NOT assignments, for example) are cached. If you are familiar |
|
856 | 857 | with Mathematica, IPython's _ variables behave exactly like |
|
857 | 858 | Mathematica's % variables. |
|
858 | 859 | |
|
859 | 860 | The following GLOBAL variables always exist (so don't overwrite them!): |
|
860 | 861 | |
|
861 | 862 | * [_] (a single underscore) : stores previous output, like Python's |
|
862 | 863 | default interpreter. |
|
863 | 864 | * [__] (two underscores): next previous. |
|
864 | 865 | * [___] (three underscores): next-next previous. |
|
865 | 866 | |
|
866 | 867 | Additionally, global variables named _<n> are dynamically created (<n> |
|
867 | 868 | being the prompt counter), such that the result of output <n> is always |
|
868 | 869 | available as _<n> (don't use the angle brackets, just the number, e.g. |
|
869 | 870 | _21). |
|
870 | 871 | |
|
871 | 872 | These global variables are all stored in a global dictionary (not a |
|
872 | 873 | list, since it only has entries for lines which returned a result) |
|
873 | 874 | available under the names _oh and Out (similar to _ih and In). So the |
|
874 | 875 | output from line 12 can be obtained as _12, Out[12] or _oh[12]. If you |
|
875 | 876 | accidentally overwrite the Out variable you can recover it by typing |
|
876 | 877 | 'Out=_oh' at the prompt. |
|
877 | 878 | |
|
878 | 879 | This system obviously can potentially put heavy memory demands on your |
|
879 | 880 | system, since it prevents Python's garbage collector from removing any |
|
880 | 881 | previously computed results. You can control how many results are kept |
|
881 | 882 | in memory with the option (at the command line or in your ipythonrc |
|
882 | 883 | file) cache_size. If you set it to 0, the whole system is completely |
|
883 | 884 | disabled and the prompts revert to the classic '>>>' of normal Python. |
|
884 | 885 | |
|
885 | 886 | |
|
886 | 887 | Directory history |
|
887 | 888 | ----------------- |
|
888 | 889 | |
|
889 | 890 | Your history of visited directories is kept in the global list _dh, and |
|
890 | 891 | the magic %cd command can be used to go to any entry in that list. The |
|
891 | 892 | %dhist command allows you to view this history. Do ``cd -<TAB`` to |
|
892 | 893 | conventiently view the directory history. |
|
893 | 894 | |
|
894 | 895 | |
|
895 | 896 | Automatic parentheses and quotes |
|
896 | 897 | -------------------------------- |
|
897 | 898 | |
|
898 | 899 | These features were adapted from Nathan Gray's LazyPython. They are |
|
899 | 900 | meant to allow less typing for common situations. |
|
900 | 901 | |
|
901 | 902 | |
|
902 | 903 | Automatic parentheses |
|
903 | 904 | --------------------- |
|
904 | 905 | |
|
905 | 906 | Callable objects (i.e. functions, methods, etc) can be invoked like this |
|
906 | 907 | (notice the commas between the arguments):: |
|
907 | 908 | |
|
908 | 909 | >>> callable_ob arg1, arg2, arg3 |
|
909 | 910 | |
|
910 | 911 | and the input will be translated to this:: |
|
911 | 912 | |
|
912 | 913 | -> callable_ob(arg1, arg2, arg3) |
|
913 | 914 | |
|
914 | 915 | You can force automatic parentheses by using '/' as the first character |
|
915 | 916 | of a line. For example:: |
|
916 | 917 | |
|
917 | 918 | >>> /globals # becomes 'globals()' |
|
918 | 919 | |
|
919 | 920 | Note that the '/' MUST be the first character on the line! This won't work:: |
|
920 | 921 | |
|
921 | 922 | >>> print /globals # syntax error |
|
922 | 923 | |
|
923 | 924 | In most cases the automatic algorithm should work, so you should rarely |
|
924 | 925 | need to explicitly invoke /. One notable exception is if you are trying |
|
925 | 926 | to call a function with a list of tuples as arguments (the parenthesis |
|
926 | 927 | will confuse IPython):: |
|
927 | 928 | |
|
928 | 929 | In [1]: zip (1,2,3),(4,5,6) # won't work |
|
929 | 930 | |
|
930 | 931 | but this will work:: |
|
931 | 932 | |
|
932 | 933 | In [2]: /zip (1,2,3),(4,5,6) |
|
933 | 934 | ---> zip ((1,2,3),(4,5,6)) |
|
934 | 935 | Out[2]= [(1, 4), (2, 5), (3, 6)] |
|
935 | 936 | |
|
936 | 937 | IPython tells you that it has altered your command line by displaying |
|
937 | 938 | the new command line preceded by ->. e.g.:: |
|
938 | 939 | |
|
939 | 940 | In [18]: callable list |
|
940 | 941 | ----> callable (list) |
|
941 | 942 | |
|
942 | 943 | |
|
943 | 944 | Automatic quoting |
|
944 | 945 | ----------------- |
|
945 | 946 | |
|
946 | 947 | You can force automatic quoting of a function's arguments by using ',' |
|
947 | 948 | or ';' as the first character of a line. For example:: |
|
948 | 949 | |
|
949 | 950 | >>> ,my_function /home/me # becomes my_function("/home/me") |
|
950 | 951 | |
|
951 | 952 | If you use ';' instead, the whole argument is quoted as a single string |
|
952 | 953 | (while ',' splits on whitespace):: |
|
953 | 954 | |
|
954 | 955 | >>> ,my_function a b c # becomes my_function("a","b","c") |
|
955 | 956 | |
|
956 | 957 | >>> ;my_function a b c # becomes my_function("a b c") |
|
957 | 958 | |
|
958 | 959 | Note that the ',' or ';' MUST be the first character on the line! This |
|
959 | 960 | won't work:: |
|
960 | 961 | |
|
961 | 962 | >>> x = ,my_function /home/me # syntax error |
|
962 | 963 | |
|
963 | 964 | IPython as your default Python environment |
|
964 | 965 | ========================================== |
|
965 | 966 | |
|
966 | 967 | Python honors the environment variable PYTHONSTARTUP and will execute at |
|
967 | 968 | startup the file referenced by this variable. If you put at the end of |
|
968 | 969 | this file the following two lines of code:: |
|
969 | 970 | |
|
970 | 971 | import IPython |
|
971 | 972 | IPython.Shell.IPShell().mainloop(sys_exit=1) |
|
972 | 973 | |
|
973 | 974 | then IPython will be your working environment anytime you start Python. |
|
974 | 975 | The sys_exit=1 is needed to have IPython issue a call to sys.exit() when |
|
975 | 976 | it finishes, otherwise you'll be back at the normal Python '>>>' |
|
976 | 977 | prompt. |
|
977 | 978 | |
|
978 | 979 | This is probably useful to developers who manage multiple Python |
|
979 | 980 | versions and don't want to have correspondingly multiple IPython |
|
980 | 981 | versions. Note that in this mode, there is no way to pass IPython any |
|
981 | 982 | command-line options, as those are trapped first by Python itself. |
|
982 | 983 | |
|
983 | 984 | .. _Embedding: |
|
984 | 985 | |
|
985 | 986 | Embedding IPython |
|
986 | 987 | ================= |
|
987 | 988 | |
|
988 | 989 | It is possible to start an IPython instance inside your own Python |
|
989 | 990 | programs. This allows you to evaluate dynamically the state of your |
|
990 | 991 | code, operate with your variables, analyze them, etc. Note however that |
|
991 | 992 | any changes you make to values while in the shell do not propagate back |
|
992 | 993 | to the running code, so it is safe to modify your values because you |
|
993 | 994 | won't break your code in bizarre ways by doing so. |
|
994 | 995 | |
|
995 | 996 | This feature allows you to easily have a fully functional python |
|
996 | 997 | environment for doing object introspection anywhere in your code with a |
|
997 | 998 | simple function call. In some cases a simple print statement is enough, |
|
998 | 999 | but if you need to do more detailed analysis of a code fragment this |
|
999 | 1000 | feature can be very valuable. |
|
1000 | 1001 | |
|
1001 | 1002 | It can also be useful in scientific computing situations where it is |
|
1002 | 1003 | common to need to do some automatic, computationally intensive part and |
|
1003 | 1004 | then stop to look at data, plots, etc. |
|
1004 | 1005 | Opening an IPython instance will give you full access to your data and |
|
1005 | 1006 | functions, and you can resume program execution once you are done with |
|
1006 | 1007 | the interactive part (perhaps to stop again later, as many times as |
|
1007 | 1008 | needed). |
|
1008 | 1009 | |
|
1009 | 1010 | The following code snippet is the bare minimum you need to include in |
|
1010 | 1011 | your Python programs for this to work (detailed examples follow later):: |
|
1011 | 1012 | |
|
1012 | 1013 | from IPython.Shell import IPShellEmbed |
|
1013 | 1014 | |
|
1014 | 1015 | ipshell = IPShellEmbed() |
|
1015 | 1016 | |
|
1016 | 1017 | ipshell() # this call anywhere in your program will start IPython |
|
1017 | 1018 | |
|
1018 | 1019 | You can run embedded instances even in code which is itself being run at |
|
1019 | 1020 | the IPython interactive prompt with '%run <filename>'. Since it's easy |
|
1020 | 1021 | to get lost as to where you are (in your top-level IPython or in your |
|
1021 | 1022 | embedded one), it's a good idea in such cases to set the in/out prompts |
|
1022 | 1023 | to something different for the embedded instances. The code examples |
|
1023 | 1024 | below illustrate this. |
|
1024 | 1025 | |
|
1025 | 1026 | You can also have multiple IPython instances in your program and open |
|
1026 | 1027 | them separately, for example with different options for data |
|
1027 | 1028 | presentation. If you close and open the same instance multiple times, |
|
1028 | 1029 | its prompt counters simply continue from each execution to the next. |
|
1029 | 1030 | |
|
1030 | 1031 | Please look at the docstrings in the Shell.py module for more details on |
|
1031 | 1032 | the use of this system. |
|
1032 | 1033 | |
|
1033 | 1034 | The following sample file illustrating how to use the embedding |
|
1034 | 1035 | functionality is provided in the examples directory as example-embed.py. |
|
1035 | 1036 | It should be fairly self-explanatory:: |
|
1036 | 1037 | |
|
1037 | 1038 | |
|
1038 | 1039 | #!/usr/bin/env python |
|
1039 | 1040 | |
|
1040 | 1041 | """An example of how to embed an IPython shell into a running program. |
|
1041 | 1042 | |
|
1042 | 1043 | Please see the documentation in the IPython.Shell module for more details. |
|
1043 | 1044 | |
|
1044 | 1045 | The accompanying file example-embed-short.py has quick code fragments for |
|
1045 | 1046 | embedding which you can cut and paste in your code once you understand how |
|
1046 | 1047 | things work. |
|
1047 | 1048 | |
|
1048 | 1049 | The code in this file is deliberately extra-verbose, meant for learning.""" |
|
1049 | 1050 | |
|
1050 | 1051 | # The basics to get you going: |
|
1051 | 1052 | |
|
1052 | 1053 | # IPython sets the __IPYTHON__ variable so you can know if you have nested |
|
1053 | 1054 | # copies running. |
|
1054 | 1055 | |
|
1055 | 1056 | # Try running this code both at the command line and from inside IPython (with |
|
1056 | 1057 | # %run example-embed.py) |
|
1057 | 1058 | try: |
|
1058 | 1059 | __IPYTHON__ |
|
1059 | 1060 | except NameError: |
|
1060 | 1061 | nested = 0 |
|
1061 | 1062 | args = [''] |
|
1062 | 1063 | else: |
|
1063 | 1064 | print "Running nested copies of IPython." |
|
1064 | 1065 | print "The prompts for the nested copy have been modified" |
|
1065 | 1066 | nested = 1 |
|
1066 | 1067 | # what the embedded instance will see as sys.argv: |
|
1067 | 1068 | args = ['-pi1','In <\\#>: ','-pi2',' .\\D.: ', |
|
1068 | 1069 | '-po','Out<\\#>: ','-nosep'] |
|
1069 | 1070 | |
|
1070 | 1071 | # First import the embeddable shell class |
|
1071 | 1072 | from IPython.Shell import IPShellEmbed |
|
1072 | 1073 | |
|
1073 | 1074 | # Now create an instance of the embeddable shell. The first argument is a |
|
1074 | 1075 | # string with options exactly as you would type them if you were starting |
|
1075 | 1076 | # IPython at the system command line. Any parameters you want to define for |
|
1076 | 1077 | # configuration can thus be specified here. |
|
1077 | 1078 | ipshell = IPShellEmbed(args, |
|
1078 | 1079 | banner = 'Dropping into IPython', |
|
1079 | 1080 | exit_msg = 'Leaving Interpreter, back to program.') |
|
1080 | 1081 | |
|
1081 | 1082 | # Make a second instance, you can have as many as you want. |
|
1082 | 1083 | if nested: |
|
1083 | 1084 | args[1] = 'In2<\\#>' |
|
1084 | 1085 | else: |
|
1085 | 1086 | args = ['-pi1','In2<\\#>: ','-pi2',' .\\D.: ', |
|
1086 | 1087 | '-po','Out<\\#>: ','-nosep'] |
|
1087 | 1088 | ipshell2 = IPShellEmbed(args,banner = 'Second IPython instance.') |
|
1088 | 1089 | |
|
1089 | 1090 | print '\nHello. This is printed from the main controller program.\n' |
|
1090 | 1091 | |
|
1091 | 1092 | # You can then call ipshell() anywhere you need it (with an optional |
|
1092 | 1093 | # message): |
|
1093 | 1094 | ipshell('***Called from top level. ' |
|
1094 | 1095 | 'Hit Ctrl-D to exit interpreter and continue program.\n' |
|
1095 | 1096 | 'Note that if you use %kill_embedded, you can fully deactivate\n' |
|
1096 | 1097 | 'This embedded instance so it will never turn on again') |
|
1097 | 1098 | |
|
1098 | 1099 | print '\nBack in caller program, moving along...\n' |
|
1099 | 1100 | |
|
1100 | 1101 | #--------------------------------------------------------------------------- |
|
1101 | 1102 | # More details: |
|
1102 | 1103 | |
|
1103 | 1104 | # IPShellEmbed instances don't print the standard system banner and |
|
1104 | 1105 | # messages. The IPython banner (which actually may contain initialization |
|
1105 | 1106 | # messages) is available as <instance>.IP.BANNER in case you want it. |
|
1106 | 1107 | |
|
1107 | 1108 | # IPShellEmbed instances print the following information everytime they |
|
1108 | 1109 | # start: |
|
1109 | 1110 | |
|
1110 | 1111 | # - A global startup banner. |
|
1111 | 1112 | |
|
1112 | 1113 | # - A call-specific header string, which you can use to indicate where in the |
|
1113 | 1114 | # execution flow the shell is starting. |
|
1114 | 1115 | |
|
1115 | 1116 | # They also print an exit message every time they exit. |
|
1116 | 1117 | |
|
1117 | 1118 | # Both the startup banner and the exit message default to None, and can be set |
|
1118 | 1119 | # either at the instance constructor or at any other time with the |
|
1119 | 1120 | # set_banner() and set_exit_msg() methods. |
|
1120 | 1121 | |
|
1121 | 1122 | # The shell instance can be also put in 'dummy' mode globally or on a per-call |
|
1122 | 1123 | # basis. This gives you fine control for debugging without having to change |
|
1123 | 1124 | # code all over the place. |
|
1124 | 1125 | |
|
1125 | 1126 | # The code below illustrates all this. |
|
1126 | 1127 | |
|
1127 | 1128 | |
|
1128 | 1129 | # This is how the global banner and exit_msg can be reset at any point |
|
1129 | 1130 | ipshell.set_banner('Entering interpreter - New Banner') |
|
1130 | 1131 | ipshell.set_exit_msg('Leaving interpreter - New exit_msg') |
|
1131 | 1132 | |
|
1132 | 1133 | def foo(m): |
|
1133 | 1134 | s = 'spam' |
|
1134 | 1135 | ipshell('***In foo(). Try @whos, or print s or m:') |
|
1135 | 1136 | print 'foo says m = ',m |
|
1136 | 1137 | |
|
1137 | 1138 | def bar(n): |
|
1138 | 1139 | s = 'eggs' |
|
1139 | 1140 | ipshell('***In bar(). Try @whos, or print s or n:') |
|
1140 | 1141 | print 'bar says n = ',n |
|
1141 | 1142 | |
|
1142 | 1143 | # Some calls to the above functions which will trigger IPython: |
|
1143 | 1144 | print 'Main program calling foo("eggs")\n' |
|
1144 | 1145 | foo('eggs') |
|
1145 | 1146 | |
|
1146 | 1147 | # The shell can be put in 'dummy' mode where calls to it silently return. This |
|
1147 | 1148 | # allows you, for example, to globally turn off debugging for a program with a |
|
1148 | 1149 | # single call. |
|
1149 | 1150 | ipshell.set_dummy_mode(1) |
|
1150 | 1151 | print '\nTrying to call IPython which is now "dummy":' |
|
1151 | 1152 | ipshell() |
|
1152 | 1153 | print 'Nothing happened...' |
|
1153 | 1154 | # The global 'dummy' mode can still be overridden for a single call |
|
1154 | 1155 | print '\nOverriding dummy mode manually:' |
|
1155 | 1156 | ipshell(dummy=0) |
|
1156 | 1157 | |
|
1157 | 1158 | # Reactivate the IPython shell |
|
1158 | 1159 | ipshell.set_dummy_mode(0) |
|
1159 | 1160 | |
|
1160 | 1161 | print 'You can even have multiple embedded instances:' |
|
1161 | 1162 | ipshell2() |
|
1162 | 1163 | |
|
1163 | 1164 | print '\nMain program calling bar("spam")\n' |
|
1164 | 1165 | bar('spam') |
|
1165 | 1166 | |
|
1166 | 1167 | print 'Main program finished. Bye!' |
|
1167 | 1168 | |
|
1168 | 1169 | #********************** End of file <example-embed.py> *********************** |
|
1169 | 1170 | |
|
1170 | 1171 | Once you understand how the system functions, you can use the following |
|
1171 | 1172 | code fragments in your programs which are ready for cut and paste:: |
|
1172 | 1173 | |
|
1173 | 1174 | |
|
1174 | 1175 | """Quick code snippets for embedding IPython into other programs. |
|
1175 | 1176 | |
|
1176 | 1177 | See example-embed.py for full details, this file has the bare minimum code for |
|
1177 | 1178 | cut and paste use once you understand how to use the system.""" |
|
1178 | 1179 | |
|
1179 | 1180 | #--------------------------------------------------------------------------- |
|
1180 | 1181 | # This code loads IPython but modifies a few things if it detects it's running |
|
1181 | 1182 | # embedded in another IPython session (helps avoid confusion) |
|
1182 | 1183 | |
|
1183 | 1184 | try: |
|
1184 | 1185 | __IPYTHON__ |
|
1185 | 1186 | except NameError: |
|
1186 | 1187 | argv = [''] |
|
1187 | 1188 | banner = exit_msg = '' |
|
1188 | 1189 | else: |
|
1189 | 1190 | # Command-line options for IPython (a list like sys.argv) |
|
1190 | 1191 | argv = ['-pi1','In <\\#>:','-pi2',' .\\D.:','-po','Out<\\#>:'] |
|
1191 | 1192 | banner = '*** Nested interpreter ***' |
|
1192 | 1193 | exit_msg = '*** Back in main IPython ***' |
|
1193 | 1194 | |
|
1194 | 1195 | # First import the embeddable shell class |
|
1195 | 1196 | from IPython.Shell import IPShellEmbed |
|
1196 | 1197 | # Now create the IPython shell instance. Put ipshell() anywhere in your code |
|
1197 | 1198 | # where you want it to open. |
|
1198 | 1199 | ipshell = IPShellEmbed(argv,banner=banner,exit_msg=exit_msg) |
|
1199 | 1200 | |
|
1200 | 1201 | #--------------------------------------------------------------------------- |
|
1201 | 1202 | # This code will load an embeddable IPython shell always with no changes for |
|
1202 | 1203 | # nested embededings. |
|
1203 | 1204 | |
|
1204 | 1205 | from IPython.Shell import IPShellEmbed |
|
1205 | 1206 | ipshell = IPShellEmbed() |
|
1206 | 1207 | # Now ipshell() will open IPython anywhere in the code. |
|
1207 | 1208 | |
|
1208 | 1209 | #--------------------------------------------------------------------------- |
|
1209 | 1210 | # This code loads an embeddable shell only if NOT running inside |
|
1210 | 1211 | # IPython. Inside IPython, the embeddable shell variable ipshell is just a |
|
1211 | 1212 | # dummy function. |
|
1212 | 1213 | |
|
1213 | 1214 | try: |
|
1214 | 1215 | __IPYTHON__ |
|
1215 | 1216 | except NameError: |
|
1216 | 1217 | from IPython.Shell import IPShellEmbed |
|
1217 | 1218 | ipshell = IPShellEmbed() |
|
1218 | 1219 | # Now ipshell() will open IPython anywhere in the code |
|
1219 | 1220 | else: |
|
1220 | 1221 | # Define a dummy ipshell() so the same code doesn't crash inside an |
|
1221 | 1222 | # interactive IPython |
|
1222 | 1223 | def ipshell(): pass |
|
1223 | 1224 | |
|
1224 | 1225 | #******************* End of file <example-embed-short.py> ******************** |
|
1225 | 1226 | |
|
1226 | 1227 | Using the Python debugger (pdb) |
|
1227 | 1228 | =============================== |
|
1228 | 1229 | |
|
1229 | 1230 | Running entire programs via pdb |
|
1230 | 1231 | ------------------------------- |
|
1231 | 1232 | |
|
1232 | 1233 | pdb, the Python debugger, is a powerful interactive debugger which |
|
1233 | 1234 | allows you to step through code, set breakpoints, watch variables, |
|
1234 | 1235 | etc. IPython makes it very easy to start any script under the control |
|
1235 | 1236 | of pdb, regardless of whether you have wrapped it into a 'main()' |
|
1236 | 1237 | function or not. For this, simply type '%run -d myscript' at an |
|
1237 | 1238 | IPython prompt. See the %run command's documentation (via '%run?' or |
|
1238 | 1239 | in Sec. magic_ for more details, including how to control where pdb |
|
1239 | 1240 | will stop execution first. |
|
1240 | 1241 | |
|
1241 | 1242 | For more information on the use of the pdb debugger, read the included |
|
1242 | 1243 | pdb.doc file (part of the standard Python distribution). On a stock |
|
1243 | 1244 | Linux system it is located at /usr/lib/python2.3/pdb.doc, but the |
|
1244 | 1245 | easiest way to read it is by using the help() function of the pdb module |
|
1245 | 1246 | as follows (in an IPython prompt): |
|
1246 | 1247 | |
|
1247 | 1248 | In [1]: import pdb |
|
1248 | 1249 | In [2]: pdb.help() |
|
1249 | 1250 | |
|
1250 | 1251 | This will load the pdb.doc document in a file viewer for you automatically. |
|
1251 | 1252 | |
|
1252 | 1253 | |
|
1253 | 1254 | Automatic invocation of pdb on exceptions |
|
1254 | 1255 | ----------------------------------------- |
|
1255 | 1256 | |
|
1256 | 1257 | IPython, if started with the -pdb option (or if the option is set in |
|
1257 | 1258 | your rc file) can call the Python pdb debugger every time your code |
|
1258 | 1259 | triggers an uncaught exception. This feature |
|
1259 | 1260 | can also be toggled at any time with the %pdb magic command. This can be |
|
1260 | 1261 | extremely useful in order to find the origin of subtle bugs, because pdb |
|
1261 | 1262 | opens up at the point in your code which triggered the exception, and |
|
1262 | 1263 | while your program is at this point 'dead', all the data is still |
|
1263 | 1264 | available and you can walk up and down the stack frame and understand |
|
1264 | 1265 | the origin of the problem. |
|
1265 | 1266 | |
|
1266 | 1267 | Furthermore, you can use these debugging facilities both with the |
|
1267 | 1268 | embedded IPython mode and without IPython at all. For an embedded shell |
|
1268 | 1269 | (see sec. Embedding_), simply call the constructor with |
|
1269 | 1270 | '-pdb' in the argument string and automatically pdb will be called if an |
|
1270 | 1271 | uncaught exception is triggered by your code. |
|
1271 | 1272 | |
|
1272 | 1273 | For stand-alone use of the feature in your programs which do not use |
|
1273 | 1274 | IPython at all, put the following lines toward the top of your 'main' |
|
1274 | 1275 | routine:: |
|
1275 | 1276 | |
|
1276 | 1277 | import sys |
|
1277 | 1278 | from IPython.core import ultratb |
|
1278 | 1279 | sys.excepthook = ultratb.FormattedTB(mode='Verbose', |
|
1279 | 1280 | color_scheme='Linux', call_pdb=1) |
|
1280 | 1281 | |
|
1281 | 1282 | The mode keyword can be either 'Verbose' or 'Plain', giving either very |
|
1282 | 1283 | detailed or normal tracebacks respectively. The color_scheme keyword can |
|
1283 | 1284 | be one of 'NoColor', 'Linux' (default) or 'LightBG'. These are the same |
|
1284 | 1285 | options which can be set in IPython with -colors and -xmode. |
|
1285 | 1286 | |
|
1286 | 1287 | This will give any of your programs detailed, colored tracebacks with |
|
1287 | 1288 | automatic invocation of pdb. |
|
1288 | 1289 | |
|
1289 | 1290 | |
|
1290 | 1291 | Extensions for syntax processing |
|
1291 | 1292 | ================================ |
|
1292 | 1293 | |
|
1293 | 1294 | This isn't for the faint of heart, because the potential for breaking |
|
1294 | 1295 | things is quite high. But it can be a very powerful and useful feature. |
|
1295 | 1296 | In a nutshell, you can redefine the way IPython processes the user input |
|
1296 | 1297 | line to accept new, special extensions to the syntax without needing to |
|
1297 | 1298 | change any of IPython's own code. |
|
1298 | 1299 | |
|
1299 | 1300 | In the IPython/extensions directory you will find some examples |
|
1300 | 1301 | supplied, which we will briefly describe now. These can be used 'as is' |
|
1301 | 1302 | (and both provide very useful functionality), or you can use them as a |
|
1302 | 1303 | starting point for writing your own extensions. |
|
1303 | 1304 | |
|
1304 | 1305 | |
|
1305 | 1306 | Pasting of code starting with '>>> ' or '... ' |
|
1306 | 1307 | ---------------------------------------------- |
|
1307 | 1308 | |
|
1308 | 1309 | In the python tutorial it is common to find code examples which have |
|
1309 | 1310 | been taken from real python sessions. The problem with those is that all |
|
1310 | 1311 | the lines begin with either '>>> ' or '... ', which makes it impossible |
|
1311 | 1312 | to paste them all at once. One must instead do a line by line manual |
|
1312 | 1313 | copying, carefully removing the leading extraneous characters. |
|
1313 | 1314 | |
|
1314 | 1315 | This extension identifies those starting characters and removes them |
|
1315 | 1316 | from the input automatically, so that one can paste multi-line examples |
|
1316 | 1317 | directly into IPython, saving a lot of time. Please look at the file |
|
1317 | 1318 | InterpreterPasteInput.py in the IPython/extensions directory for details |
|
1318 | 1319 | on how this is done. |
|
1319 | 1320 | |
|
1320 | 1321 | IPython comes with a special profile enabling this feature, called |
|
1321 | 1322 | tutorial. Simply start IPython via 'ipython -p tutorial' and the feature |
|
1322 | 1323 | will be available. In a normal IPython session you can activate the |
|
1323 | 1324 | feature by importing the corresponding module with: |
|
1324 | 1325 | In [1]: import IPython.extensions.InterpreterPasteInput |
|
1325 | 1326 | |
|
1326 | 1327 | The following is a 'screenshot' of how things work when this extension |
|
1327 | 1328 | is on, copying an example from the standard tutorial:: |
|
1328 | 1329 | |
|
1329 | 1330 | IPython profile: tutorial |
|
1330 | 1331 | |
|
1331 | 1332 | *** Pasting of code with ">>>" or "..." has been enabled. |
|
1332 | 1333 | |
|
1333 | 1334 | In [1]: >>> def fib2(n): # return Fibonacci series up to n |
|
1334 | 1335 | ...: ... """Return a list containing the Fibonacci series up to |
|
1335 | 1336 | n.""" |
|
1336 | 1337 | ...: ... result = [] |
|
1337 | 1338 | ...: ... a, b = 0, 1 |
|
1338 | 1339 | ...: ... while b < n: |
|
1339 | 1340 | ...: ... result.append(b) # see below |
|
1340 | 1341 | ...: ... a, b = b, a+b |
|
1341 | 1342 | ...: ... return result |
|
1342 | 1343 | ...: |
|
1343 | 1344 | |
|
1344 | 1345 | In [2]: fib2(10) |
|
1345 | 1346 | Out[2]: [1, 1, 2, 3, 5, 8] |
|
1346 | 1347 | |
|
1347 | 1348 | Note that as currently written, this extension does not recognize |
|
1348 | 1349 | IPython's prompts for pasting. Those are more complicated, since the |
|
1349 | 1350 | user can change them very easily, they involve numbers and can vary in |
|
1350 | 1351 | length. One could however extract all the relevant information from the |
|
1351 | 1352 | IPython instance and build an appropriate regular expression. This is |
|
1352 | 1353 | left as an exercise for the reader. |
|
1353 | 1354 | |
|
1354 | 1355 | |
|
1355 | 1356 | Input of physical quantities with units |
|
1356 | 1357 | --------------------------------------- |
|
1357 | 1358 | |
|
1358 | 1359 | The module PhysicalQInput allows a simplified form of input for physical |
|
1359 | 1360 | quantities with units. This file is meant to be used in conjunction with |
|
1360 | 1361 | the PhysicalQInteractive module (in the same directory) and |
|
1361 | 1362 | Physics.PhysicalQuantities from Konrad Hinsen's ScientificPython |
|
1362 | 1363 | (http://dirac.cnrs-orleans.fr/ScientificPython/). |
|
1363 | 1364 | |
|
1364 | 1365 | The Physics.PhysicalQuantities module defines PhysicalQuantity objects, |
|
1365 | 1366 | but these must be declared as instances of a class. For example, to |
|
1366 | 1367 | define v as a velocity of 3 m/s, normally you would write:: |
|
1367 | 1368 | |
|
1368 | 1369 | In [1]: v = PhysicalQuantity(3,'m/s') |
|
1369 | 1370 | |
|
1370 | 1371 | Using the PhysicalQ_Input extension this can be input instead as: |
|
1371 | 1372 | In [1]: v = 3 m/s |
|
1372 | 1373 | which is much more convenient for interactive use (even though it is |
|
1373 | 1374 | blatantly invalid Python syntax). |
|
1374 | 1375 | |
|
1375 | 1376 | The physics profile supplied with IPython (enabled via 'ipython -p |
|
1376 | 1377 | physics') uses these extensions, which you can also activate with: |
|
1377 | 1378 | |
|
1378 | 1379 | from math import * # math MUST be imported BEFORE PhysicalQInteractive |
|
1379 | 1380 | from IPython.extensions.PhysicalQInteractive import * |
|
1380 | 1381 | import IPython.extensions.PhysicalQInput |
|
1381 | 1382 | |
|
1382 | 1383 | .. _gui_support: |
|
1383 | 1384 | |
|
1384 | 1385 | GUI event loop support support |
|
1385 | 1386 | ============================== |
|
1386 | 1387 | |
|
1387 | 1388 | .. versionadded:: 0.11 |
|
1388 | 1389 | The ``%gui`` magic and :mod:`IPython.lib.inputhook`. |
|
1389 | 1390 | |
|
1390 | 1391 | IPython has excellent support for working interactively with Graphical User |
|
1391 | 1392 | Interface (GUI) toolkits, such as wxPython, PyQt4, PyGTK and Tk. This is |
|
1392 | 1393 | implemented using Python's builtin ``PyOSInputHook`` hook. This implementation |
|
1393 | 1394 | is extremely robust compared to our previous threaded based version. The |
|
1394 | 1395 | advantages of this are: |
|
1395 | 1396 | |
|
1396 | 1397 | * GUIs can be enabled and disabled dynamically at runtime. |
|
1397 | 1398 | * The active GUI can be switched dynamically at runtime. |
|
1398 | 1399 | * In some cases, multiple GUIs can run simultaneously with no problems. |
|
1399 | 1400 | * There is a developer API in :mod:`IPython.lib.inputhook` for customizing |
|
1400 | 1401 | all of these things. |
|
1401 | 1402 | |
|
1402 | 1403 | For users, enabling GUI event loop integration is simple. You simple use the |
|
1403 | 1404 | ``%gui`` magic as follows:: |
|
1404 | 1405 | |
|
1405 | 1406 | %gui [-a] [GUINAME] |
|
1406 | 1407 | |
|
1407 | 1408 | With no arguments, ``%gui`` removes all GUI support. Valid ``GUINAME`` |
|
1408 | 1409 | arguments are ``wx``, ``qt4``, ``gtk`` and ``tk``. The ``-a`` option will |
|
1409 | 1410 | create and return a running application object for the selected GUI toolkit. |
|
1410 | 1411 | |
|
1411 | 1412 | Thus, to use wxPython interactively and create a running :class:`wx.App` |
|
1412 | 1413 | object, do:: |
|
1413 | 1414 | |
|
1414 | 1415 | %gui -a wx |
|
1415 | 1416 | |
|
1416 | 1417 | For information on IPython's Matplotlib integration (and the ``pylab`` mode) |
|
1417 | 1418 | see :ref:`this section <matplotlib_support>`. |
|
1418 | 1419 | |
|
1419 | 1420 | For developers that want to use IPython's GUI event loop integration in |
|
1420 | 1421 | the form of a library, these capabilities are exposed in library form |
|
1421 | 1422 | in the :mod:`IPython.lib.inputhook`. Interested developers should see the |
|
1422 | 1423 | module docstrings for more information, but there are a few points that |
|
1423 | 1424 | should be mentioned here. |
|
1424 | 1425 | |
|
1425 | 1426 | First, the ``PyOSInputHook`` approach only works in command line settings |
|
1426 | 1427 | where readline is activated. |
|
1427 | 1428 | |
|
1428 | 1429 | Second, when using the ``PyOSInputHook`` approach, a GUI application should |
|
1429 | 1430 | *not* start its event loop. Instead all of this is handled by the |
|
1430 | 1431 | ``PyOSInputHook``. This means that applications that are meant to be used both |
|
1431 | 1432 | in IPython and as standalone apps need to have special code to detects how the |
|
1432 | 1433 | application is being run. We highly recommend using IPython's |
|
1433 | 1434 | :func:`appstart_` functions for this. Here is a simple example that shows the |
|
1434 | 1435 | recommended code that should be at the bottom of a wxPython using GUI |
|
1435 | 1436 | application:: |
|
1436 | 1437 | |
|
1437 | 1438 | try: |
|
1438 | 1439 | from IPython import appstart_wx |
|
1439 | 1440 | appstart_wx(app) |
|
1440 | 1441 | except ImportError: |
|
1441 | 1442 | app.MainLoop() |
|
1442 | 1443 | |
|
1443 | 1444 | This pattern should be used instead of the simple ``app.MainLoop()`` code |
|
1444 | 1445 | that a standalone wxPython application would have. |
|
1445 | 1446 | |
|
1446 | 1447 | Third, unlike previous versions of IPython, we no longer "hijack" (replace |
|
1447 | 1448 | them with no-ops) the event loops. This is done to allow applications that |
|
1448 | 1449 | actually need to run the real event loops to do so. This is often needed to |
|
1449 | 1450 | process pending events at critical points. |
|
1450 | 1451 | |
|
1451 | 1452 | Finally, we also have a number of examples in our source directory |
|
1452 | 1453 | :file:`docs/examples/lib` that demonstrate these capabilities. |
|
1453 | 1454 | |
|
1454 | 1455 | .. _matplotlib_support: |
|
1455 | 1456 | |
|
1456 | 1457 | Plotting with matplotlib |
|
1457 | 1458 | ======================== |
|
1458 | 1459 | |
|
1459 | 1460 | |
|
1460 | 1461 | `Matplotlib`_ provides high quality 2D and |
|
1461 | 1462 | 3D plotting for Python. Matplotlib can produce plots on screen using a variety |
|
1462 | 1463 | of GUI toolkits, including Tk, PyGTK, PyQt4 and wxPython. It also provides a |
|
1463 | 1464 | number of commands useful for scientific computing, all with a syntax |
|
1464 | 1465 | compatible with that of the popular Matlab program. |
|
1465 | 1466 | |
|
1466 | 1467 | Many IPython users have come to rely on IPython's ``-pylab`` mode which |
|
1467 | 1468 | automates the integration of Matplotlib with IPython. We are still in the |
|
1468 | 1469 | process of working with the Matplotlib developers to finalize the new pylab |
|
1469 | 1470 | API, but for now you can use Matplotlib interactively using the following |
|
1470 | 1471 | commands:: |
|
1471 | 1472 | |
|
1472 | 1473 | %gui -a wx |
|
1473 | 1474 | import matplotlib |
|
1474 | 1475 | matplotlib.use('wxagg') |
|
1475 | 1476 | from matplotlib import pylab |
|
1476 | 1477 | pylab.interactive(True) |
|
1477 | 1478 | |
|
1478 | 1479 | All of this will soon be automated as Matplotlib beings to include |
|
1479 | 1480 | new logic that uses our new GUI support. |
|
1480 | 1481 | |
|
1481 | 1482 | .. _interactive_demos: |
|
1482 | 1483 | |
|
1483 | 1484 | Interactive demos with IPython |
|
1484 | 1485 | ============================== |
|
1485 | 1486 | |
|
1486 | 1487 | IPython ships with a basic system for running scripts interactively in |
|
1487 | 1488 | sections, useful when presenting code to audiences. A few tags embedded |
|
1488 | 1489 | in comments (so that the script remains valid Python code) divide a file |
|
1489 | 1490 | into separate blocks, and the demo can be run one block at a time, with |
|
1490 | 1491 | IPython printing (with syntax highlighting) the block before executing |
|
1491 | 1492 | it, and returning to the interactive prompt after each block. The |
|
1492 | 1493 | interactive namespace is updated after each block is run with the |
|
1493 | 1494 | contents of the demo's namespace. |
|
1494 | 1495 | |
|
1495 | 1496 | This allows you to show a piece of code, run it and then execute |
|
1496 | 1497 | interactively commands based on the variables just created. Once you |
|
1497 | 1498 | want to continue, you simply execute the next block of the demo. The |
|
1498 | 1499 | following listing shows the markup necessary for dividing a script into |
|
1499 | 1500 | sections for execution as a demo:: |
|
1500 | 1501 | |
|
1501 | 1502 | |
|
1502 | 1503 | """A simple interactive demo to illustrate the use of IPython's Demo class. |
|
1503 | 1504 | |
|
1504 | 1505 | Any python script can be run as a demo, but that does little more than showing |
|
1505 | 1506 | it on-screen, syntax-highlighted in one shot. If you add a little simple |
|
1506 | 1507 | markup, you can stop at specified intervals and return to the ipython prompt, |
|
1507 | 1508 | resuming execution later. |
|
1508 | 1509 | """ |
|
1509 | 1510 | |
|
1510 | 1511 | print 'Hello, welcome to an interactive IPython demo.' |
|
1511 | 1512 | print 'Executing this block should require confirmation before proceeding,' |
|
1512 | 1513 | print 'unless auto_all has been set to true in the demo object' |
|
1513 | 1514 | |
|
1514 | 1515 | # The mark below defines a block boundary, which is a point where IPython will |
|
1515 | 1516 | # stop execution and return to the interactive prompt. |
|
1516 | 1517 | # Note that in actual interactive execution, |
|
1517 | 1518 | # <demo> --- stop --- |
|
1518 | 1519 | |
|
1519 | 1520 | x = 1 |
|
1520 | 1521 | y = 2 |
|
1521 | 1522 | |
|
1522 | 1523 | # <demo> --- stop --- |
|
1523 | 1524 | |
|
1524 | 1525 | # the mark below makes this block as silent |
|
1525 | 1526 | # <demo> silent |
|
1526 | 1527 | |
|
1527 | 1528 | print 'This is a silent block, which gets executed but not printed.' |
|
1528 | 1529 | |
|
1529 | 1530 | # <demo> --- stop --- |
|
1530 | 1531 | # <demo> auto |
|
1531 | 1532 | print 'This is an automatic block.' |
|
1532 | 1533 | print 'It is executed without asking for confirmation, but printed.' |
|
1533 | 1534 | z = x+y |
|
1534 | 1535 | |
|
1535 | 1536 | print 'z=',x |
|
1536 | 1537 | |
|
1537 | 1538 | # <demo> --- stop --- |
|
1538 | 1539 | # This is just another normal block. |
|
1539 | 1540 | print 'z is now:', z |
|
1540 | 1541 | |
|
1541 | 1542 | print 'bye!' |
|
1542 | 1543 | |
|
1543 | 1544 | In order to run a file as a demo, you must first make a Demo object out |
|
1544 | 1545 | of it. If the file is named myscript.py, the following code will make a |
|
1545 | 1546 | demo:: |
|
1546 | 1547 | |
|
1547 | 1548 | from IPython.demo import Demo |
|
1548 | 1549 | |
|
1549 | 1550 | mydemo = Demo('myscript.py') |
|
1550 | 1551 | |
|
1551 | 1552 | This creates the mydemo object, whose blocks you run one at a time by |
|
1552 | 1553 | simply calling the object with no arguments. If you have autocall active |
|
1553 | 1554 | in IPython (the default), all you need to do is type:: |
|
1554 | 1555 | |
|
1555 | 1556 | mydemo |
|
1556 | 1557 | |
|
1557 | 1558 | and IPython will call it, executing each block. Demo objects can be |
|
1558 | 1559 | restarted, you can move forward or back skipping blocks, re-execute the |
|
1559 | 1560 | last block, etc. Simply use the Tab key on a demo object to see its |
|
1560 | 1561 | methods, and call '?' on them to see their docstrings for more usage |
|
1561 | 1562 | details. In addition, the demo module itself contains a comprehensive |
|
1562 | 1563 | docstring, which you can access via:: |
|
1563 | 1564 | |
|
1564 | 1565 | from IPython import demo |
|
1565 | 1566 | |
|
1566 | 1567 | demo? |
|
1567 | 1568 | |
|
1568 | 1569 | Limitations: It is important to note that these demos are limited to |
|
1569 | 1570 | fairly simple uses. In particular, you can not put division marks in |
|
1570 | 1571 | indented code (loops, if statements, function definitions, etc.) |
|
1571 | 1572 | Supporting something like this would basically require tracking the |
|
1572 | 1573 | internal execution state of the Python interpreter, so only top-level |
|
1573 | 1574 | divisions are allowed. If you want to be able to open an IPython |
|
1574 | 1575 | instance at an arbitrary point in a program, you can use IPython's |
|
1575 | 1576 | embedding facilities, described in detail in Sec. 9 |
|
1576 | 1577 | |
|
1577 | 1578 | .. [Matplotlib] Matplotlib. http://matplotlib.sourceforge.net |
|
1578 | 1579 |
@@ -1,336 +1,336 b'' | |||
|
1 | 1 | .. _tutorial: |
|
2 | 2 | |
|
3 | 3 | ====================== |
|
4 | 4 | Quick IPython tutorial |
|
5 | 5 | ====================== |
|
6 | 6 | |
|
7 | 7 | .. warning:: |
|
8 | 8 | |
|
9 | 9 | As of the 0.11 version of IPython, some of the features and APIs |
|
10 | 10 | described in this section have been deprecated or are broken. Our plan |
|
11 | 11 | is to continue to support these features, but they need to be updated |
|
12 | 12 | to take advantage of recent API changes. Furthermore, this section |
|
13 | 13 | of the documentation need to be updated to reflect all of these changes. |
|
14 | 14 | |
|
15 | 15 | IPython can be used as an improved replacement for the Python prompt, |
|
16 | 16 | and for that you don't really need to read any more of this manual. But |
|
17 | 17 | in this section we'll try to summarize a few tips on how to make the |
|
18 | 18 | most effective use of it for everyday Python development, highlighting |
|
19 | 19 | things you might miss in the rest of the manual (which is getting long). |
|
20 | 20 | We'll give references to parts in the manual which provide more detail |
|
21 | 21 | when appropriate. |
|
22 | 22 | |
|
23 | 23 | The following article by Jeremy Jones provides an introductory tutorial |
|
24 | 24 | about IPython: http://www.onlamp.com/pub/a/python/2005/01/27/ipython.html |
|
25 | 25 | |
|
26 | 26 | Highlights |
|
27 | 27 | ========== |
|
28 | 28 | |
|
29 | 29 | Tab completion |
|
30 | 30 | -------------- |
|
31 | 31 | |
|
32 | 32 | TAB-completion, especially for attributes, is a convenient way to explore the |
|
33 | 33 | structure of any object you're dealing with. Simply type object_name.<TAB> and |
|
34 | 34 | a list of the object's attributes will be printed (see :ref:`the readline |
|
35 | 35 | section <readline>` for more). Tab completion also works on file and directory |
|
36 | 36 | names, which combined with IPython's alias system allows you to do from within |
|
37 | 37 | IPython many of the things you normally would need the system shell for. |
|
38 | 38 | |
|
39 | 39 | Explore your objects |
|
40 | 40 | -------------------- |
|
41 | 41 | |
|
42 | 42 | Typing object_name? will print all sorts of details about any object, |
|
43 | 43 | including docstrings, function definition lines (for call arguments) and |
|
44 | 44 | constructor details for classes. The magic commands %pdoc, %pdef, %psource |
|
45 | 45 | and %pfile will respectively print the docstring, function definition line, |
|
46 | 46 | full source code and the complete file for any object (when they can be |
|
47 | 47 | found). If automagic is on (it is by default), you don't need to type the '%' |
|
48 | 48 | explicitly. See :ref:`this section <dynamic_object_info>` for more. |
|
49 | 49 | |
|
50 | 50 | The `%run` magic command |
|
51 | 51 | ------------------------ |
|
52 | 52 | |
|
53 | 53 | The %run magic command allows you to run any python script and load all of its |
|
54 | 54 | data directly into the interactive namespace. Since the file is re-read from |
|
55 | 55 | disk each time, changes you make to it are reflected immediately (in contrast |
|
56 | 56 | to the behavior of import). I rarely use import for code I am testing, relying |
|
57 | 57 | on %run instead. See :ref:`this section <magic>` for more on this and other |
|
58 | 58 | magic commands, or type the name of any magic command and ? to get details on |
|
59 | 59 | it. See also :ref:`this section <dreload>` for a recursive reload command. %run |
|
60 | 60 | also has special flags for timing the execution of your scripts (-t) and for |
|
61 | 61 | executing them under the control of either Python's pdb debugger (-d) or |
|
62 | 62 | profiler (-p). With all of these, %run can be used as the main tool for |
|
63 | 63 | efficient interactive development of code which you write in your editor of |
|
64 | 64 | choice. |
|
65 | 65 | |
|
66 | 66 | Debug a Python script |
|
67 | 67 | --------------------- |
|
68 | 68 | |
|
69 | 69 | Use the Python debugger, pdb. The %pdb command allows you to toggle on and off |
|
70 | 70 | the automatic invocation of an IPython-enhanced pdb debugger (with coloring, |
|
71 | 71 | tab completion and more) at any uncaught exception. The advantage of this is |
|
72 | 72 | that pdb starts inside the function where the exception occurred, with all data |
|
73 | 73 | still available. You can print variables, see code, execute statements and even |
|
74 | 74 | walk up and down the call stack to track down the true source of the problem |
|
75 | 75 | (which often is many layers in the stack above where the exception gets |
|
76 | 76 | triggered). Running programs with %run and pdb active can be an efficient to |
|
77 | 77 | develop and debug code, in many cases eliminating the need for print statements |
|
78 | 78 | or external debugging tools. I often simply put a 1/0 in a place where I want |
|
79 | 79 | to take a look so that pdb gets called, quickly view whatever variables I need |
|
80 | 80 | to or test various pieces of code and then remove the 1/0. Note also that '%run |
|
81 | 81 | -d' activates pdb and automatically sets initial breakpoints for you to step |
|
82 | 82 | through your code, watch variables, etc. The :ref:`output caching section |
|
83 | 83 | <output_caching>` has more details. |
|
84 | 84 | |
|
85 | 85 | Use the output cache |
|
86 | 86 | -------------------- |
|
87 | 87 | |
|
88 | 88 | All output results are automatically stored in a global dictionary named Out |
|
89 | 89 | and variables named _1, _2, etc. alias them. For example, the result of input |
|
90 | 90 | line 4 is available either as Out[4] or as _4. Additionally, three variables |
|
91 | 91 | named _, __ and ___ are always kept updated with the for the last three |
|
92 | 92 | results. This allows you to recall any previous result and further use it for |
|
93 | 93 | new calculations. See :ref:`the output caching section <output_caching>` for |
|
94 | 94 | more. |
|
95 | 95 | |
|
96 | 96 | Suppress output |
|
97 | 97 | --------------- |
|
98 | 98 | |
|
99 | 99 | Put a ';' at the end of a line to suppress the printing of output. This is |
|
100 | 100 | useful when doing calculations which generate long output you are not |
|
101 | 101 | interested in seeing. The _* variables and the Out[] list do get updated with |
|
102 | 102 | the contents of the output, even if it is not printed. You can thus still |
|
103 | 103 | access the generated results this way for further processing. |
|
104 | 104 | |
|
105 | 105 | Input cache |
|
106 | 106 | ----------- |
|
107 | 107 | |
|
108 | 108 | A similar system exists for caching input. All input is stored in a global |
|
109 | 109 | list called In , so you can re-execute lines 22 through 28 plus line 34 by |
|
110 | 110 | typing 'exec In[22:29]+In[34]' (using Python slicing notation). If you need |
|
111 | 111 | to execute the same set of lines often, you can assign them to a macro with |
|
112 | 112 | the %macro function. See :ref:`here <input_caching>` for more. |
|
113 | 113 | |
|
114 | 114 | Use your input history |
|
115 | 115 | ---------------------- |
|
116 | 116 | |
|
117 | 117 | The %hist command can show you all previous input, without line numbers if |
|
118 | 118 | desired (option -n) so you can directly copy and paste code either back in |
|
119 | 119 | IPython or in a text editor. You can also save all your history by turning on |
|
120 | 120 | logging via %logstart; these logs can later be either reloaded as IPython |
|
121 | 121 | sessions or used as code for your programs. |
|
122 | 122 | |
|
123 | 123 | In particular, note taht the %rep magic function can repeat a command or get a |
|
124 | 124 | command to the input line for further editing:: |
|
125 | 125 | |
|
126 | 126 | $ l = ["hei", "vaan"] |
|
127 | 127 | $ "".join(l) |
|
128 | 128 | ==> heivaan |
|
129 | 129 | $ %rep |
|
130 | 130 | $ heivaan_ <== cursor blinking |
|
131 | 131 | |
|
132 | 132 | For more details, type ``%rep?`` as usual. |
|
133 | 133 | |
|
134 | 134 | Define your own system aliases |
|
135 | 135 | ------------------------------ |
|
136 | 136 | |
|
137 | 137 | Even though IPython gives you access to your system shell via the ! prefix, |
|
138 | 138 | it is convenient to have aliases to the system commands you use most often. |
|
139 | 139 | This allows you to work seamlessly from inside IPython with the same commands |
|
140 | 140 | you are used to in your system shell. IPython comes with some pre-defined |
|
141 | 141 | aliases and a complete system for changing directories, both via a stack (see |
|
142 | 142 | %pushd, %popd and %dhist) and via direct %cd. The latter keeps a history of |
|
143 | 143 | visited directories and allows you to go to any previously visited one. |
|
144 | 144 | |
|
145 | 145 | Call system shell commands |
|
146 | 146 | -------------------------- |
|
147 | 147 | |
|
148 | 148 | Use Python to manipulate the results of system commands. The '!!' special |
|
149 | 149 | syntax, and the %sc and %sx magic commands allow you to capture system output |
|
150 | 150 | into Python variables. |
|
151 | 151 | |
|
152 | 152 | Use Python variables when calling the shell |
|
153 | 153 | ------------------------------------------- |
|
154 | 154 | |
|
155 | 155 | Expand python variables when calling the shell (either via '!' and '!!' or via |
|
156 | 156 | aliases) by prepending a $ in front of them. You can also expand complete |
|
157 | 157 | python expressions. See :ref:`our shell section <system_shell_access>` for |
|
158 | 158 | more details. |
|
159 | 159 | |
|
160 | 160 | Use profiles |
|
161 | 161 | ------------ |
|
162 | 162 | |
|
163 | 163 | Use profiles to maintain different configurations (modules to load, function |
|
164 | 164 | definitions, option settings) for particular tasks. You can then have |
|
165 | 165 | customized versions of IPython for specific purposes. :ref:`This section |
|
166 | 166 | <profiles>` has more details. |
|
167 | 167 | |
|
168 | 168 | |
|
169 | 169 | Embed IPython in your programs |
|
170 | 170 | ------------------------------ |
|
171 | 171 | |
|
172 | 172 | A few lines of code are enough to load a complete IPython inside your own |
|
173 | 173 | programs, giving you the ability to work with your data interactively after |
|
174 | 174 | automatic processing has been completed. See :ref:`here <embedding>` for more. |
|
175 | 175 | |
|
176 | 176 | Use the Python profiler |
|
177 | 177 | ----------------------- |
|
178 | 178 | |
|
179 | 179 | When dealing with performance issues, the %run command with a -p option |
|
180 | 180 | allows you to run complete programs under the control of the Python profiler. |
|
181 | 181 | The %prun command does a similar job for single Python expressions (like |
|
182 | 182 | function calls). |
|
183 | 183 | |
|
184 | 184 | Use IPython to present interactive demos |
|
185 | 185 | ---------------------------------------- |
|
186 | 186 | |
|
187 | 187 | Use the IPython.demo.Demo class to load any Python script as an interactive |
|
188 | 188 | demo. With a minimal amount of simple markup, you can control the execution of |
|
189 | 189 | the script, stopping as needed. See :ref:`here <interactive_demos>` for more. |
|
190 | 190 | |
|
191 | 191 | Run doctests |
|
192 | 192 | ------------ |
|
193 | 193 | |
|
194 | 194 | Run your doctests from within IPython for development and debugging. The |
|
195 | 195 | special %doctest_mode command toggles a mode where the prompt, output and |
|
196 | 196 | exceptions display matches as closely as possible that of the default Python |
|
197 | 197 | interpreter. In addition, this mode allows you to directly paste in code that |
|
198 | 198 | contains leading '>>>' prompts, even if they have extra leading whitespace |
|
199 | 199 | (as is common in doctest files). This combined with the '%history -tn' call |
|
200 | 200 | to see your translated history (with these extra prompts removed and no line |
|
201 | 201 | numbers) allows for an easy doctest workflow, where you can go from doctest |
|
202 | 202 | to interactive execution to pasting into valid Python code as needed. |
|
203 | 203 | |
|
204 | 204 | Source code handling tips |
|
205 | 205 | ========================= |
|
206 | 206 | |
|
207 | 207 | IPython is a line-oriented program, without full control of the |
|
208 | 208 | terminal. Therefore, it doesn't support true multiline editing. However, |
|
209 | 209 | it has a number of useful tools to help you in dealing effectively with |
|
210 | 210 | more complex editing. |
|
211 | 211 | |
|
212 | 212 | The %edit command gives a reasonable approximation of multiline editing, |
|
213 | 213 | by invoking your favorite editor on the spot. IPython will execute the |
|
214 | 214 | code you type in there as if it were typed interactively. Type %edit? |
|
215 | 215 | for the full details on the edit command. |
|
216 | 216 | |
|
217 | 217 | If you have typed various commands during a session, which you'd like to |
|
218 | 218 | reuse, IPython provides you with a number of tools. Start by using %hist |
|
219 | 219 | to see your input history, so you can see the line numbers of all input. |
|
220 | 220 | Let us say that you'd like to reuse lines 10 through 20, plus lines 24 |
|
221 | 221 | and 28. All the commands below can operate on these with the syntax:: |
|
222 | 222 | |
|
223 | 223 | %command 10-20 24 28 |
|
224 | 224 | |
|
225 | 225 | where the command given can be: |
|
226 | 226 | |
|
227 | 227 | * %macro <macroname>: this stores the lines into a variable which, |
|
228 | 228 | when called at the prompt, re-executes the input. Macros can be |
|
229 | 229 | edited later using '%edit macroname', and they can be stored |
|
230 | 230 | persistently across sessions with '%store macroname' (the storage |
|
231 | 231 | system is per-profile). The combination of quick macros, |
|
232 | 232 | persistent storage and editing, allows you to easily refine |
|
233 | 233 | quick-and-dirty interactive input into permanent utilities, always |
|
234 | 234 | available both in IPython and as files for general reuse. |
|
235 | 235 | * %edit: this will open a text editor with those lines pre-loaded |
|
236 | 236 | for further modification. It will then execute the resulting |
|
237 | 237 | file's contents as if you had typed it at the prompt. |
|
238 | 238 | * %save <filename>: this saves the lines directly to a named file on |
|
239 | 239 | disk. |
|
240 | 240 | |
|
241 | 241 | While %macro saves input lines into memory for interactive re-execution, |
|
242 | 242 | sometimes you'd like to save your input directly to a file. The %save |
|
243 | 243 | magic does this: its input sytnax is the same as %macro, but it saves |
|
244 | 244 | your input directly to a Python file. Note that the %logstart command |
|
245 | 245 | also saves input, but it logs all input to disk (though you can |
|
246 | 246 | temporarily suspend it and reactivate it with %logoff/%logon); %save |
|
247 | 247 | allows you to select which lines of input you need to save. |
|
248 | 248 | |
|
249 | 249 | |
|
250 | 250 | Lightweight 'version control' |
|
251 | 251 | ============================= |
|
252 | 252 | |
|
253 | 253 | When you call %edit with no arguments, IPython opens an empty editor |
|
254 | 254 | with a temporary file, and it returns the contents of your editing |
|
255 | 255 | session as a string variable. Thanks to IPython's output caching |
|
256 | 256 | mechanism, this is automatically stored:: |
|
257 | 257 | |
|
258 | 258 | In [1]: %edit |
|
259 | 259 | |
|
260 | 260 | IPython will make a temporary file named: /tmp/ipython_edit_yR-HCN.py |
|
261 | 261 | |
|
262 | 262 | Editing... done. Executing edited code... |
|
263 | 263 | |
|
264 | 264 | hello - this is a temporary file |
|
265 | 265 | |
|
266 | 266 | Out[1]: "print 'hello - this is a temporary file'\n" |
|
267 | 267 | |
|
268 | 268 | Now, if you call '%edit -p', IPython tries to open an editor with the |
|
269 | 269 | same data as the last time you used %edit. So if you haven't used %edit |
|
270 | 270 | in the meantime, this same contents will reopen; however, it will be |
|
271 | 271 | done in a new file. This means that if you make changes and you later |
|
272 | 272 | want to find an old version, you can always retrieve it by using its |
|
273 | 273 | output number, via '%edit _NN', where NN is the number of the output |
|
274 | 274 | prompt. |
|
275 | 275 | |
|
276 | 276 | Continuing with the example above, this should illustrate this idea:: |
|
277 | 277 | |
|
278 | 278 | In [2]: edit -p |
|
279 | 279 | |
|
280 | 280 | IPython will make a temporary file named: /tmp/ipython_edit_nA09Qk.py |
|
281 | 281 | |
|
282 | 282 | Editing... done. Executing edited code... |
|
283 | 283 | |
|
284 | 284 | hello - now I made some changes |
|
285 | 285 | |
|
286 | 286 | Out[2]: "print 'hello - now I made some changes'\n" |
|
287 | 287 | |
|
288 | 288 | In [3]: edit _1 |
|
289 | 289 | |
|
290 | 290 | IPython will make a temporary file named: /tmp/ipython_edit_gy6-zD.py |
|
291 | 291 | |
|
292 | 292 | Editing... done. Executing edited code... |
|
293 | 293 | |
|
294 | 294 | hello - this is a temporary file |
|
295 | 295 | |
|
296 | 296 | IPython version control at work :) |
|
297 | 297 | |
|
298 | 298 | Out[3]: "print 'hello - this is a temporary file'\nprint 'IPython version control at work :)'\n" |
|
299 | 299 | |
|
300 | 300 | |
|
301 | 301 | This section was written after a contribution by Alexander Belchenko on |
|
302 | 302 | the IPython user list. |
|
303 | 303 | |
|
304 | 304 | |
|
305 | 305 | Effective logging |
|
306 | 306 | ================= |
|
307 | 307 | |
|
308 | 308 | A very useful suggestion sent in by Robert Kern follows: |
|
309 | 309 | |
|
310 | 310 | I recently happened on a nifty way to keep tidy per-project log files. I |
|
311 | 311 | made a profile for my project (which is called "parkfield"):: |
|
312 | 312 | |
|
313 | 313 | include ipythonrc |
|
314 | 314 | |
|
315 | 315 | # cancel earlier logfile invocation: |
|
316 | 316 | |
|
317 | 317 | logfile '' |
|
318 | 318 | |
|
319 | 319 | execute import time |
|
320 | 320 | |
|
321 | 321 | execute __cmd = '/Users/kern/research/logfiles/parkfield-%s.log rotate' |
|
322 | 322 | |
|
323 | 323 | execute __IP.magic_logstart(__cmd % time.strftime('%Y-%m-%d')) |
|
324 | 324 | |
|
325 | 325 | I also added a shell alias for convenience:: |
|
326 | 326 | |
|
327 |
alias parkfield="ipython -pylab |
|
|
327 | alias parkfield="ipython --pylab profile=parkfield" | |
|
328 | 328 | |
|
329 | 329 | Now I have a nice little directory with everything I ever type in, |
|
330 | 330 | organized by project and date. |
|
331 | 331 | |
|
332 | 332 | Contribute your own: If you have your own favorite tip on using IPython |
|
333 | 333 | efficiently for a certain task (especially things which can't be done in |
|
334 | 334 | the normal Python interpreter), don't hesitate to send it! |
|
335 | 335 | |
|
336 | 336 |
General Comments 0
You need to be logged in to leave comments.
Login now