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1 =================
1 =================
2 IPython reference
2 IPython reference
3 =================
3 =================
4
4
5 .. _command_line_options:
5 .. _command_line_options:
6
6
7 Command-line usage
7 Command-line usage
8 ==================
8 ==================
9
9
10 You start IPython with the command::
10 You start IPython with the command::
11
11
12 $ ipython [options] files
12 $ ipython [options] files
13
13
14 .. note::
15
16 For IPython on Python 3, use ``ipython3`` in place of ``ipython``.
17
14 If invoked with no options, it executes all the files listed in sequence
18 If invoked with no options, it executes all the files listed in sequence
15 and drops you into the interpreter while still acknowledging any options
19 and drops you into the interpreter while still acknowledging any options
16 you may have set in your ipython_config.py. This behavior is different from
20 you may have set in your ipython_config.py. This behavior is different from
17 standard Python, which when called as python -i will only execute one
21 standard Python, which when called as python -i will only execute one
18 file and ignore your configuration setup.
22 file and ignore your configuration setup.
19
23
20 Please note that some of the configuration options are not available at
24 Please note that some of the configuration options are not available at
21 the command line, simply because they are not practical here. Look into
25 the command line, simply because they are not practical here. Look into
22 your configuration files for details on those. There are separate configuration
26 your configuration files for details on those. There are separate configuration
23 files for each profile, and the files look like "ipython_config.py" or
27 files for each profile, and the files look like "ipython_config.py" or
24 "ipython_config_<frontendname>.py". Profile directories look like
28 "ipython_config_<frontendname>.py". Profile directories look like
25 "profile_profilename" and are typically installed in the IPYTHON_DIR directory.
29 "profile_profilename" and are typically installed in the IPYTHON_DIR directory.
26 For Linux users, this will be $HOME/.config/ipython, and for other users it
30 For Linux users, this will be $HOME/.config/ipython, and for other users it
27 will be $HOME/.ipython. For Windows users, $HOME resolves to C:\\Documents and
31 will be $HOME/.ipython. For Windows users, $HOME resolves to C:\\Documents and
28 Settings\\YourUserName in most instances.
32 Settings\\YourUserName in most instances.
29
33
30
34
31 Eventloop integration
35 Eventloop integration
32 ---------------------
36 ---------------------
33
37
34 Previously IPython had command line options for controlling GUI event loop
38 Previously IPython had command line options for controlling GUI event loop
35 integration (-gthread, -qthread, -q4thread, -wthread, -pylab). As of IPython
39 integration (-gthread, -qthread, -q4thread, -wthread, -pylab). As of IPython
36 version 0.11, these have been removed. Please see the new ``%gui``
40 version 0.11, these have been removed. Please see the new ``%gui``
37 magic command or :ref:`this section <gui_support>` for details on the new
41 magic command or :ref:`this section <gui_support>` for details on the new
38 interface, or specify the gui at the commandline::
42 interface, or specify the gui at the commandline::
39
43
40 $ ipython --gui=qt
44 $ ipython --gui=qt
41
45
42
46
43 Regular Options
47 Regular Options
44 ---------------
48 ---------------
45
49
46 After the above threading options have been given, regular options can
50 After the above threading options have been given, regular options can
47 follow in any order. All options can be abbreviated to their shortest
51 follow in any order. All options can be abbreviated to their shortest
48 non-ambiguous form and are case-sensitive. One or two dashes can be
52 non-ambiguous form and are case-sensitive.
49 used. Some options have an alternate short form, indicated after a ``|``.
50
53
51 Most options can also be set from your configuration file. See the provided
54 Most options can also be set from your configuration file. See the provided
52 example for more details on what the options do. Options given at the command
55 example for more details on what the options do. Options given at the command
53 line override the values set in the configuration file.
56 line override the values set in the configuration file.
54
57
55 All options with a [no] prepended can be specified in negated form
58 All options with a [no] prepended can be specified in negated form
56 (--no-option instead of --option) to turn the feature off.
59 (--no-option instead of --option) to turn the feature off.
57
60
58 ``-h, --help`` print a help message and exit.
61 ``-h, --help`` print a help message and exit.
59
62
60 ``--pylab, pylab=<name>``
63 ``--pylab, pylab=<name>``
61 See :ref:`Matplotlib support <matplotlib_support>`
64 See :ref:`Matplotlib support <matplotlib_support>`
62 for more details.
65 for more details.
63
66
64 ``--autocall=<val>``
67 ``--autocall=<val>``
65 Make IPython automatically call any callable object even if you
68 Make IPython automatically call any callable object even if you
66 didn't type explicit parentheses. For example, 'str 43' becomes
69 didn't type explicit parentheses. For example, 'str 43' becomes
67 'str(43)' automatically. The value can be '0' to disable the feature,
70 'str(43)' automatically. The value can be '0' to disable the feature,
68 '1' for smart autocall, where it is not applied if there are no more
71 '1' for smart autocall, where it is not applied if there are no more
69 arguments on the line, and '2' for full autocall, where all callable
72 arguments on the line, and '2' for full autocall, where all callable
70 objects are automatically called (even if no arguments are
73 objects are automatically called (even if no arguments are
71 present). The default is '1'.
74 present). The default is '1'.
72
75
73 ``--[no-]autoindent``
76 ``--[no-]autoindent``
74 Turn automatic indentation on/off.
77 Turn automatic indentation on/off.
75
78
76 ``--[no-]automagic``
79 ``--[no-]automagic``
77 make magic commands automatic (without needing their first character
80 make magic commands automatic (without needing their first character
78 to be %). Type %magic at the IPython prompt for more information.
81 to be %). Type %magic at the IPython prompt for more information.
79
82
80 ``--[no-]autoedit_syntax``
83 ``--[no-]autoedit_syntax``
81 When a syntax error occurs after editing a file, automatically
84 When a syntax error occurs after editing a file, automatically
82 open the file to the trouble causing line for convenient
85 open the file to the trouble causing line for convenient
83 fixing.
86 fixing.
84
87
85 ``--[no-]banner``
88 ``--[no-]banner``
86 Print the initial information banner (default on).
89 Print the initial information banner (default on).
87
90
88 ``-c <command>``
91 ``-c <command>``
89 execute the given command string. This is similar to the -c
92 execute the given command string. This is similar to the -c
90 option in the normal Python interpreter.
93 option in the normal Python interpreter.
91
94
92 ``--cache-size=<n>``
95 ``--cache-size=<n>``
93 size of the output cache (maximum number of entries to hold in
96 size of the output cache (maximum number of entries to hold in
94 memory). The default is 1000, you can change it permanently in your
97 memory). The default is 1000, you can change it permanently in your
95 config file. Setting it to 0 completely disables the caching system,
98 config file. Setting it to 0 completely disables the caching system,
96 and the minimum value accepted is 20 (if you provide a value less than
99 and the minimum value accepted is 20 (if you provide a value less than
97 20, it is reset to 0 and a warning is issued) This limit is defined
100 20, it is reset to 0 and a warning is issued) This limit is defined
98 because otherwise you'll spend more time re-flushing a too small cache
101 because otherwise you'll spend more time re-flushing a too small cache
99 than working.
102 than working.
100
103
101 ``--classic``
104 ``--classic``
102 Gives IPython a similar feel to the classic Python
105 Gives IPython a similar feel to the classic Python
103 prompt.
106 prompt.
104
107
105 ``--colors=<scheme>``
108 ``--colors=<scheme>``
106 Color scheme for prompts and exception reporting. Currently
109 Color scheme for prompts and exception reporting. Currently
107 implemented: NoColor, Linux and LightBG.
110 implemented: NoColor, Linux and LightBG.
108
111
109 ``--[no-]color_info``
112 ``--[no-]color_info``
110 IPython can display information about objects via a set of functions,
113 IPython can display information about objects via a set of functions,
111 and optionally can use colors for this, syntax highlighting source
114 and optionally can use colors for this, syntax highlighting source
112 code and various other elements. However, because this information is
115 code and various other elements. However, because this information is
113 passed through a pager (like 'less') and many pagers get confused with
116 passed through a pager (like 'less') and many pagers get confused with
114 color codes, this option is off by default. You can test it and turn
117 color codes, this option is off by default. You can test it and turn
115 it on permanently in your configuration file if it works for you. As a
118 it on permanently in your configuration file if it works for you. As a
116 reference, the 'less' pager supplied with Mandrake 8.2 works ok, but
119 reference, the 'less' pager supplied with Mandrake 8.2 works ok, but
117 that in RedHat 7.2 doesn't.
120 that in RedHat 7.2 doesn't.
118
121
119 Test it and turn it on permanently if it works with your
122 Test it and turn it on permanently if it works with your
120 system. The magic function %color_info allows you to toggle this
123 system. The magic function %color_info allows you to toggle this
121 interactively for testing.
124 interactively for testing.
122
125
123 ``--[no-]debug``
126 ``--[no-]debug``
124 Show information about the loading process. Very useful to pin down
127 Show information about the loading process. Very useful to pin down
125 problems with your configuration files or to get details about
128 problems with your configuration files or to get details about
126 session restores.
129 session restores.
127
130
128 ``--[no-]deep_reload``
131 ``--[no-]deep_reload``
129 IPython can use the deep_reload module which reloads changes in
132 IPython can use the deep_reload module which reloads changes in
130 modules recursively (it replaces the reload() function, so you don't
133 modules recursively (it replaces the reload() function, so you don't
131 need to change anything to use it). deep_reload() forces a full
134 need to change anything to use it). deep_reload() forces a full
132 reload of modules whose code may have changed, which the default
135 reload of modules whose code may have changed, which the default
133 reload() function does not.
136 reload() function does not.
134
137
135 When deep_reload is off, IPython will use the normal reload(),
138 When deep_reload is off, IPython will use the normal reload(),
136 but deep_reload will still be available as dreload(). This
139 but deep_reload will still be available as dreload(). This
137 feature is off by default [which means that you have both
140 feature is off by default [which means that you have both
138 normal reload() and dreload()].
141 normal reload() and dreload()].
139
142
140 ``--editor=<name>``
143 ``--editor=<name>``
141 Which editor to use with the %edit command. By default,
144 Which editor to use with the %edit command. By default,
142 IPython will honor your EDITOR environment variable (if not
145 IPython will honor your EDITOR environment variable (if not
143 set, vi is the Unix default and notepad the Windows one).
146 set, vi is the Unix default and notepad the Windows one).
144 Since this editor is invoked on the fly by IPython and is
147 Since this editor is invoked on the fly by IPython and is
145 meant for editing small code snippets, you may want to use a
148 meant for editing small code snippets, you may want to use a
146 small, lightweight editor here (in case your default EDITOR is
149 small, lightweight editor here (in case your default EDITOR is
147 something like Emacs).
150 something like Emacs).
148
151
149 ``--ipython_dir=<name>``
152 ``--ipython_dir=<name>``
150 name of your IPython configuration directory IPYTHON_DIR. This
153 name of your IPython configuration directory IPYTHON_DIR. This
151 can also be specified through the environment variable
154 can also be specified through the environment variable
152 IPYTHON_DIR.
155 IPYTHON_DIR.
153
156
154 ``--logfile=<name>``
157 ``--logfile=<name>``
155 specify the name of your logfile.
158 specify the name of your logfile.
156
159
157 This implies ``%logstart`` at the beginning of your session
160 This implies ``%logstart`` at the beginning of your session
158
161
159 generate a log file of all input. The file is named
162 generate a log file of all input. The file is named
160 ipython_log.py in your current directory (which prevents logs
163 ipython_log.py in your current directory (which prevents logs
161 from multiple IPython sessions from trampling each other). You
164 from multiple IPython sessions from trampling each other). You
162 can use this to later restore a session by loading your
165 can use this to later restore a session by loading your
163 logfile with ``ipython -i ipython_log.py``
166 logfile with ``ipython -i ipython_log.py``
164
167
165 ``--logplay=<name>``
168 ``--logplay=<name>``
166
169
167 NOT AVAILABLE in 0.11
170 NOT AVAILABLE in 0.11
168
171
169 you can replay a previous log. For restoring a session as close as
172 you can replay a previous log. For restoring a session as close as
170 possible to the state you left it in, use this option (don't just run
173 possible to the state you left it in, use this option (don't just run
171 the logfile). With -logplay, IPython will try to reconstruct the
174 the logfile). With -logplay, IPython will try to reconstruct the
172 previous working environment in full, not just execute the commands in
175 previous working environment in full, not just execute the commands in
173 the logfile.
176 the logfile.
174
177
175 When a session is restored, logging is automatically turned on
178 When a session is restored, logging is automatically turned on
176 again with the name of the logfile it was invoked with (it is
179 again with the name of the logfile it was invoked with (it is
177 read from the log header). So once you've turned logging on for
180 read from the log header). So once you've turned logging on for
178 a session, you can quit IPython and reload it as many times as
181 a session, you can quit IPython and reload it as many times as
179 you want and it will continue to log its history and restore
182 you want and it will continue to log its history and restore
180 from the beginning every time.
183 from the beginning every time.
181
184
182 Caveats: there are limitations in this option. The history
185 Caveats: there are limitations in this option. The history
183 variables _i*,_* and _dh don't get restored properly. In the
186 variables _i*,_* and _dh don't get restored properly. In the
184 future we will try to implement full session saving by writing
187 future we will try to implement full session saving by writing
185 and retrieving a 'snapshot' of the memory state of IPython. But
188 and retrieving a 'snapshot' of the memory state of IPython. But
186 our first attempts failed because of inherent limitations of
189 our first attempts failed because of inherent limitations of
187 Python's Pickle module, so this may have to wait.
190 Python's Pickle module, so this may have to wait.
188
191
189 ``--[no-]messages``
192 ``--[no-]messages``
190 Print messages which IPython collects about its startup
193 Print messages which IPython collects about its startup
191 process (default on).
194 process (default on).
192
195
193 ``--[no-]pdb``
196 ``--[no-]pdb``
194 Automatically call the pdb debugger after every uncaught
197 Automatically call the pdb debugger after every uncaught
195 exception. If you are used to debugging using pdb, this puts
198 exception. If you are used to debugging using pdb, this puts
196 you automatically inside of it after any call (either in
199 you automatically inside of it after any call (either in
197 IPython or in code called by it) which triggers an exception
200 IPython or in code called by it) which triggers an exception
198 which goes uncaught.
201 which goes uncaught.
199
202
200 ``--[no-]pprint``
203 ``--[no-]pprint``
201 ipython can optionally use the pprint (pretty printer) module
204 ipython can optionally use the pprint (pretty printer) module
202 for displaying results. pprint tends to give a nicer display
205 for displaying results. pprint tends to give a nicer display
203 of nested data structures. If you like it, you can turn it on
206 of nested data structures. If you like it, you can turn it on
204 permanently in your config file (default off).
207 permanently in your config file (default off).
205
208
206 ``--profile=<name>``
209 ``--profile=<name>``
207
210
208 Select the IPython profile by name.
211 Select the IPython profile by name.
209
212
210 This is a quick way to keep and load multiple
213 This is a quick way to keep and load multiple
211 config files for different tasks, especially if you use the
214 config files for different tasks, especially if you use the
212 include option of config files. You can keep a basic
215 include option of config files. You can keep a basic
213 :file:`IPYTHON_DIR/profile_default/ipython_config.py` file
216 :file:`IPYTHON_DIR/profile_default/ipython_config.py` file
214 and then have other 'profiles' which
217 and then have other 'profiles' which
215 include this one and load extra things for particular
218 include this one and load extra things for particular
216 tasks. For example:
219 tasks. For example:
217
220
218 1. $IPYTHON_DIR/profile_default : load basic things you always want.
221 1. $IPYTHON_DIR/profile_default : load basic things you always want.
219 2. $IPYTHON_DIR/profile_math : load (1) and basic math-related modules.
222 2. $IPYTHON_DIR/profile_math : load (1) and basic math-related modules.
220 3. $IPYTHON_DIR/profile_numeric : load (1) and Numeric and plotting modules.
223 3. $IPYTHON_DIR/profile_numeric : load (1) and Numeric and plotting modules.
221
224
222 Since it is possible to create an endless loop by having
225 Since it is possible to create an endless loop by having
223 circular file inclusions, IPython will stop if it reaches 15
226 circular file inclusions, IPython will stop if it reaches 15
224 recursive inclusions.
227 recursive inclusions.
225
228
226 ``InteractiveShell.prompt_in1=<string>``
229 ``InteractiveShell.prompt_in1=<string>``
227
230
228 Specify the string used for input prompts. Note that if you are using
231 Specify the string used for input prompts. Note that if you are using
229 numbered prompts, the number is represented with a '\#' in the
232 numbered prompts, the number is represented with a '\#' in the
230 string. Don't forget to quote strings with spaces embedded in
233 string. Don't forget to quote strings with spaces embedded in
231 them. Default: 'In [\#]:'. The :ref:`prompts section <prompts>`
234 them. Default: 'In [\#]:'. The :ref:`prompts section <prompts>`
232 discusses in detail all the available escapes to customize your
235 discusses in detail all the available escapes to customize your
233 prompts.
236 prompts.
234
237
235 ``InteractiveShell.prompt_in2=<string>``
238 ``InteractiveShell.prompt_in2=<string>``
236 Similar to the previous option, but used for the continuation
239 Similar to the previous option, but used for the continuation
237 prompts. The special sequence '\D' is similar to '\#', but
240 prompts. The special sequence '\D' is similar to '\#', but
238 with all digits replaced dots (so you can have your
241 with all digits replaced dots (so you can have your
239 continuation prompt aligned with your input prompt). Default:
242 continuation prompt aligned with your input prompt). Default:
240 ' .\D.:' (note three spaces at the start for alignment with
243 ' .\D.:' (note three spaces at the start for alignment with
241 'In [\#]').
244 'In [\#]').
242
245
243 ``InteractiveShell.prompt_out=<string>``
246 ``InteractiveShell.prompt_out=<string>``
244 String used for output prompts, also uses numbers like
247 String used for output prompts, also uses numbers like
245 prompt_in1. Default: 'Out[\#]:'
248 prompt_in1. Default: 'Out[\#]:'
246
249
247 ``--quick``
250 ``--quick``
248 start in bare bones mode (no config file loaded).
251 start in bare bones mode (no config file loaded).
249
252
250 ``config_file=<name>``
253 ``config_file=<name>``
251 name of your IPython resource configuration file. Normally
254 name of your IPython resource configuration file. Normally
252 IPython loads ipython_config.py (from current directory) or
255 IPython loads ipython_config.py (from current directory) or
253 IPYTHON_DIR/profile_default.
256 IPYTHON_DIR/profile_default.
254
257
255 If the loading of your config file fails, IPython starts with
258 If the loading of your config file fails, IPython starts with
256 a bare bones configuration (no modules loaded at all).
259 a bare bones configuration (no modules loaded at all).
257
260
258 ``--[no-]readline``
261 ``--[no-]readline``
259 use the readline library, which is needed to support name
262 use the readline library, which is needed to support name
260 completion and command history, among other things. It is
263 completion and command history, among other things. It is
261 enabled by default, but may cause problems for users of
264 enabled by default, but may cause problems for users of
262 X/Emacs in Python comint or shell buffers.
265 X/Emacs in Python comint or shell buffers.
263
266
264 Note that X/Emacs 'eterm' buffers (opened with M-x term) support
267 Note that X/Emacs 'eterm' buffers (opened with M-x term) support
265 IPython's readline and syntax coloring fine, only 'emacs' (M-x
268 IPython's readline and syntax coloring fine, only 'emacs' (M-x
266 shell and C-c !) buffers do not.
269 shell and C-c !) buffers do not.
267
270
268 ``--TerminalInteractiveShell.screen_length=<n>``
271 ``--TerminalInteractiveShell.screen_length=<n>``
269 number of lines of your screen. This is used to control
272 number of lines of your screen. This is used to control
270 printing of very long strings. Strings longer than this number
273 printing of very long strings. Strings longer than this number
271 of lines will be sent through a pager instead of directly
274 of lines will be sent through a pager instead of directly
272 printed.
275 printed.
273
276
274 The default value for this is 0, which means IPython will
277 The default value for this is 0, which means IPython will
275 auto-detect your screen size every time it needs to print certain
278 auto-detect your screen size every time it needs to print certain
276 potentially long strings (this doesn't change the behavior of the
279 potentially long strings (this doesn't change the behavior of the
277 'print' keyword, it's only triggered internally). If for some
280 'print' keyword, it's only triggered internally). If for some
278 reason this isn't working well (it needs curses support), specify
281 reason this isn't working well (it needs curses support), specify
279 it yourself. Otherwise don't change the default.
282 it yourself. Otherwise don't change the default.
280
283
281 ``--TerminalInteractiveShell.separate_in=<string>``
284 ``--TerminalInteractiveShell.separate_in=<string>``
282
285
283 separator before input prompts.
286 separator before input prompts.
284 Default: '\n'
287 Default: '\n'
285
288
286 ``--TerminalInteractiveShell.separate_out=<string>``
289 ``--TerminalInteractiveShell.separate_out=<string>``
287 separator before output prompts.
290 separator before output prompts.
288 Default: nothing.
291 Default: nothing.
289
292
290 ``--TerminalInteractiveShell.separate_out2=<string>``
293 ``--TerminalInteractiveShell.separate_out2=<string>``
291 separator after output prompts.
294 separator after output prompts.
292 Default: nothing.
295 Default: nothing.
293 For these three options, use the value 0 to specify no separator.
296 For these three options, use the value 0 to specify no separator.
294
297
295 ``--nosep``
298 ``--nosep``
296 shorthand for setting the above separators to empty strings.
299 shorthand for setting the above separators to empty strings.
297
300
298 Simply removes all input/output separators.
301 Simply removes all input/output separators.
299
302
300 ``--init``
303 ``--init``
301 allows you to initialize a profile dir for configuration when you
304 allows you to initialize a profile dir for configuration when you
302 install a new version of IPython or want to use a new profile.
305 install a new version of IPython or want to use a new profile.
303 Since new versions may include new command line options or example
306 Since new versions may include new command line options or example
304 files, this copies updated config files. Note that you should probably
307 files, this copies updated config files. Note that you should probably
305 use %upgrade instead,it's a safer alternative.
308 use %upgrade instead,it's a safer alternative.
306
309
307 ``--version`` print version information and exit.
310 ``--version`` print version information and exit.
308
311
309 ``--xmode=<modename>``
312 ``--xmode=<modename>``
310
313
311 Mode for exception reporting.
314 Mode for exception reporting.
312
315
313 Valid modes: Plain, Context and Verbose.
316 Valid modes: Plain, Context and Verbose.
314
317
315 * Plain: similar to python's normal traceback printing.
318 * Plain: similar to python's normal traceback printing.
316 * Context: prints 5 lines of context source code around each
319 * Context: prints 5 lines of context source code around each
317 line in the traceback.
320 line in the traceback.
318 * Verbose: similar to Context, but additionally prints the
321 * Verbose: similar to Context, but additionally prints the
319 variables currently visible where the exception happened
322 variables currently visible where the exception happened
320 (shortening their strings if too long). This can potentially be
323 (shortening their strings if too long). This can potentially be
321 very slow, if you happen to have a huge data structure whose
324 very slow, if you happen to have a huge data structure whose
322 string representation is complex to compute. Your computer may
325 string representation is complex to compute. Your computer may
323 appear to freeze for a while with cpu usage at 100%. If this
326 appear to freeze for a while with cpu usage at 100%. If this
324 occurs, you can cancel the traceback with Ctrl-C (maybe hitting it
327 occurs, you can cancel the traceback with Ctrl-C (maybe hitting it
325 more than once).
328 more than once).
326
329
327 Interactive use
330 Interactive use
328 ===============
331 ===============
329
332
330 IPython is meant to work as a drop-in replacement for the standard interactive
333 IPython is meant to work as a drop-in replacement for the standard interactive
331 interpreter. As such, any code which is valid python should execute normally
334 interpreter. As such, any code which is valid python should execute normally
332 under IPython (cases where this is not true should be reported as bugs). It
335 under IPython (cases where this is not true should be reported as bugs). It
333 does, however, offer many features which are not available at a standard python
336 does, however, offer many features which are not available at a standard python
334 prompt. What follows is a list of these.
337 prompt. What follows is a list of these.
335
338
336
339
337 Caution for Windows users
340 Caution for Windows users
338 -------------------------
341 -------------------------
339
342
340 Windows, unfortunately, uses the '\\' character as a path separator. This is a
343 Windows, unfortunately, uses the '\\' character as a path separator. This is a
341 terrible choice, because '\\' also represents the escape character in most
344 terrible choice, because '\\' also represents the escape character in most
342 modern programming languages, including Python. For this reason, using '/'
345 modern programming languages, including Python. For this reason, using '/'
343 character is recommended if you have problems with ``\``. However, in Windows
346 character is recommended if you have problems with ``\``. However, in Windows
344 commands '/' flags options, so you can not use it for the root directory. This
347 commands '/' flags options, so you can not use it for the root directory. This
345 means that paths beginning at the root must be typed in a contrived manner
348 means that paths beginning at the root must be typed in a contrived manner
346 like: ``%copy \opt/foo/bar.txt \tmp``
349 like: ``%copy \opt/foo/bar.txt \tmp``
347
350
348 .. _magic:
351 .. _magic:
349
352
350 Magic command system
353 Magic command system
351 --------------------
354 --------------------
352
355
353 IPython will treat any line whose first character is a % as a special
356 IPython will treat any line whose first character is a % as a special
354 call to a 'magic' function. These allow you to control the behavior of
357 call to a 'magic' function. These allow you to control the behavior of
355 IPython itself, plus a lot of system-type features. They are all
358 IPython itself, plus a lot of system-type features. They are all
356 prefixed with a % character, but parameters are given without
359 prefixed with a % character, but parameters are given without
357 parentheses or quotes.
360 parentheses or quotes.
358
361
359 Example: typing ``%cd mydir`` changes your working directory to 'mydir', if it
362 Example: typing ``%cd mydir`` changes your working directory to 'mydir', if it
360 exists.
363 exists.
361
364
362 If you have 'automagic' enabled (as it by default), you don't need
365 If you have 'automagic' enabled (as it by default), you don't need
363 to type in the % explicitly. IPython will scan its internal list of
366 to type in the % explicitly. IPython will scan its internal list of
364 magic functions and call one if it exists. With automagic on you can
367 magic functions and call one if it exists. With automagic on you can
365 then just type ``cd mydir`` to go to directory 'mydir'. The automagic
368 then just type ``cd mydir`` to go to directory 'mydir'. The automagic
366 system has the lowest possible precedence in name searches, so defining
369 system has the lowest possible precedence in name searches, so defining
367 an identifier with the same name as an existing magic function will
370 an identifier with the same name as an existing magic function will
368 shadow it for automagic use. You can still access the shadowed magic
371 shadow it for automagic use. You can still access the shadowed magic
369 function by explicitly using the % character at the beginning of the line.
372 function by explicitly using the % character at the beginning of the line.
370
373
371 An example (with automagic on) should clarify all this:
374 An example (with automagic on) should clarify all this:
372
375
373 .. sourcecode:: ipython
376 .. sourcecode:: ipython
374
377
375 In [1]: cd ipython # %cd is called by automagic
378 In [1]: cd ipython # %cd is called by automagic
376
377 /home/fperez/ipython
379 /home/fperez/ipython
378
380
379 In [2]: cd=1 # now cd is just a variable
381 In [2]: cd=1 # now cd is just a variable
380
381 In [3]: cd .. # and doesn't work as a function anymore
382
383 ------------------------------
384
385 File "<console>", line 1
386
387 cd ..
388
389 ^
390
382
383 In [3]: cd .. # and doesn't work as a function anymore
384 File "<ipython-input-3-9fedb3aff56c>", line 1
385 cd ..
386 ^
391 SyntaxError: invalid syntax
387 SyntaxError: invalid syntax
392
388
393 In [4]: %cd .. # but %cd always works
394
389
390 In [4]: %cd .. # but %cd always works
395 /home/fperez
391 /home/fperez
396
392
397 In [5]: del cd # if you remove the cd variable
393 In [5]: del cd # if you remove the cd variable, automagic works again
398
394
399 In [6]: cd ipython # automagic can work again
395 In [6]: cd ipython
400
396
401 /home/fperez/ipython
397 /home/fperez/ipython
402
398
403 You can define your own magic functions to extend the system. The
399 You can define your own magic functions to extend the system. The
404 following example defines a new magic command, %impall:
400 following example defines a new magic command, %impall:
405
401
406 .. sourcecode:: python
402 .. sourcecode:: python
407
403
408 ip = get_ipython()
404 ip = get_ipython()
409
405
410 def doimp(self, arg):
406 def doimp(self, arg):
411
412 ip = self.api
407 ip = self.api
408 ip.ex("import %s; reload(%s); from %s import *" % (arg,arg,arg) )
413
409
414 ip.ex("import %s; reload(%s); from %s import *" % (
410 ip.define_magic('impall', doimp)
415
416 arg,arg,arg)
417
418 )
419
411
420 ip.expose_magic('impall', doimp)
412 Type ``%magic`` for more information, including a list of all available magic
421
422 Type `%magic` for more information, including a list of all available magic
423 functions at any time and their docstrings. You can also type
413 functions at any time and their docstrings. You can also type
424 %magic_function_name? (see :ref:`below <dynamic_object_info` for information on
414 ``%magic_function_name?`` (see :ref:`below <dynamic_object_info>` for information on
425 the '?' system) to get information about any particular magic function you are
415 the '?' system) to get information about any particular magic function you are
426 interested in.
416 interested in.
427
417
428 The API documentation for the :mod:`IPython.core.magic` module contains the full
418 The API documentation for the :mod:`IPython.core.magic` module contains the full
429 docstrings of all currently available magic commands.
419 docstrings of all currently available magic commands.
430
420
431
421
432 Access to the standard Python help
422 Access to the standard Python help
433 ----------------------------------
423 ----------------------------------
434
424
435 As of Python 2.1, a help system is available with access to object docstrings
425 Simply type ``help()`` to access Python's standard help system. You can
436 and the Python manuals. Simply type 'help' (no quotes) to access it. You can
426 also type ``help(object)`` for information about a given object, or
437 also type help(object) to obtain information about a given object, and
427 ``help('keyword')`` for information on a keyword. You may need to configure your
438 help('keyword') for information on a keyword. As noted :ref:`here
428 PYTHONDOCS environment variable for this feature to work correctly.
439 <accessing_help>`, you need to properly configure your environment variable
440 PYTHONDOCS for this feature to work correctly.
441
429
442 .. _dynamic_object_info:
430 .. _dynamic_object_info:
443
431
444 Dynamic object information
432 Dynamic object information
445 --------------------------
433 --------------------------
446
434
447 Typing ``?word`` or ``word?`` prints detailed information about an object. If
435 Typing ``?word`` or ``word?`` prints detailed information about an object. If
448 certain strings in the object are too long (docstrings, code, etc.) they get
436 certain strings in the object are too long (e.g. function signatures) they get
449 snipped in the center for brevity. This system gives access variable types and
437 snipped in the center for brevity. This system gives access variable types and
450 values, full source code for any object (if available), function prototypes and
438 values, docstrings, function prototypes and other useful information.
451 other useful information.
439
440 If the information will not fit in the terminal, it is displayed in a pager
441 (``less`` if available, otherwise a basic internal pager).
452
442
453 Typing ``??word`` or ``word??`` gives access to the full information without
443 Typing ``??word`` or ``word??`` gives access to the full information, including
454 snipping long strings. Long strings are sent to the screen through the
444 the source code where possible. Long strings are not snipped.
455 less pager if longer than the screen and printed otherwise. On systems
456 lacking the less command, IPython uses a very basic internal pager.
457
445
458 The following magic functions are particularly useful for gathering
446 The following magic functions are particularly useful for gathering
459 information about your working environment. You can get more details by
447 information about your working environment. You can get more details by
460 typing ``%magic`` or querying them individually (use %function_name? with or
448 typing ``%magic`` or querying them individually (``%function_name?``);
461 without the %), this is just a summary:
449 this is just a summary:
462
450
463 * **%pdoc <object>**: Print (or run through a pager if too long) the
451 * **%pdoc <object>**: Print (or run through a pager if too long) the
464 docstring for an object. If the given object is a class, it will
452 docstring for an object. If the given object is a class, it will
465 print both the class and the constructor docstrings.
453 print both the class and the constructor docstrings.
466 * **%pdef <object>**: Print the definition header for any callable
454 * **%pdef <object>**: Print the definition header for any callable
467 object. If the object is a class, print the constructor information.
455 object. If the object is a class, print the constructor information.
468 * **%psource <object>**: Print (or run through a pager if too long)
456 * **%psource <object>**: Print (or run through a pager if too long)
469 the source code for an object.
457 the source code for an object.
470 * **%pfile <object>**: Show the entire source file where an object was
458 * **%pfile <object>**: Show the entire source file where an object was
471 defined via a pager, opening it at the line where the object
459 defined via a pager, opening it at the line where the object
472 definition begins.
460 definition begins.
473 * **%who/%whos**: These functions give information about identifiers
461 * **%who/%whos**: These functions give information about identifiers
474 you have defined interactively (not things you loaded or defined
462 you have defined interactively (not things you loaded or defined
475 in your configuration files). %who just prints a list of
463 in your configuration files). %who just prints a list of
476 identifiers and %whos prints a table with some basic details about
464 identifiers and %whos prints a table with some basic details about
477 each identifier.
465 each identifier.
478
466
479 Note that the dynamic object information functions (?/??, ``%pdoc``,
467 Note that the dynamic object information functions (?/??, ``%pdoc``,
480 ``%pfile``, ``%pdef``, ``%psource``) give you access to documentation even on
468 ``%pfile``, ``%pdef``, ``%psource``) work on object attributes, as well as
481 things which are not really defined as separate identifiers. Try for example
469 directly on variables. For example, after doing ``import os``, you can use
482 typing {}.get? or after doing import os, type ``os.path.abspath??``.
470 ``os.path.abspath??``.
483
471
484 .. _readline:
472 .. _readline:
485
473
486 Readline-based features
474 Readline-based features
487 -----------------------
475 -----------------------
488
476
489 These features require the GNU readline library, so they won't work if your
477 These features require the GNU readline library, so they won't work if your
490 Python installation lacks readline support. We will first describe the default
478 Python installation lacks readline support. We will first describe the default
491 behavior IPython uses, and then how to change it to suit your preferences.
479 behavior IPython uses, and then how to change it to suit your preferences.
492
480
493
481
494 Command line completion
482 Command line completion
495 +++++++++++++++++++++++
483 +++++++++++++++++++++++
496
484
497 At any time, hitting TAB will complete any available python commands or
485 At any time, hitting TAB will complete any available python commands or
498 variable names, and show you a list of the possible completions if
486 variable names, and show you a list of the possible completions if
499 there's no unambiguous one. It will also complete filenames in the
487 there's no unambiguous one. It will also complete filenames in the
500 current directory if no python names match what you've typed so far.
488 current directory if no python names match what you've typed so far.
501
489
502
490
503 Search command history
491 Search command history
504 ++++++++++++++++++++++
492 ++++++++++++++++++++++
505
493
506 IPython provides two ways for searching through previous input and thus
494 IPython provides two ways for searching through previous input and thus
507 reduce the need for repetitive typing:
495 reduce the need for repetitive typing:
508
496
509 1. Start typing, and then use Ctrl-p (previous,up) and Ctrl-n
497 1. Start typing, and then use Ctrl-p (previous,up) and Ctrl-n
510 (next,down) to search through only the history items that match
498 (next,down) to search through only the history items that match
511 what you've typed so far. If you use Ctrl-p/Ctrl-n at a blank
499 what you've typed so far. If you use Ctrl-p/Ctrl-n at a blank
512 prompt, they just behave like normal arrow keys.
500 prompt, they just behave like normal arrow keys.
513 2. Hit Ctrl-r: opens a search prompt. Begin typing and the system
501 2. Hit Ctrl-r: opens a search prompt. Begin typing and the system
514 searches your history for lines that contain what you've typed so
502 searches your history for lines that contain what you've typed so
515 far, completing as much as it can.
503 far, completing as much as it can.
516
504
517
505
518 Persistent command history across sessions
506 Persistent command history across sessions
519 ++++++++++++++++++++++++++++++++++++++++++
507 ++++++++++++++++++++++++++++++++++++++++++
520
508
521 IPython will save your input history when it leaves and reload it next
509 IPython will save your input history when it leaves and reload it next
522 time you restart it. By default, the history file is named
510 time you restart it. By default, the history file is named
523 $IPYTHON_DIR/profile_<name>/history.sqlite. This allows you to keep
511 $IPYTHON_DIR/profile_<name>/history.sqlite. This allows you to keep
524 separate histories related to various tasks: commands related to
512 separate histories related to various tasks: commands related to
525 numerical work will not be clobbered by a system shell history, for
513 numerical work will not be clobbered by a system shell history, for
526 example.
514 example.
527
515
528
516
529 Autoindent
517 Autoindent
530 ++++++++++
518 ++++++++++
531
519
532 IPython can recognize lines ending in ':' and indent the next line,
520 IPython can recognize lines ending in ':' and indent the next line,
533 while also un-indenting automatically after 'raise' or 'return'.
521 while also un-indenting automatically after 'raise' or 'return'.
534
522
535 This feature uses the readline library, so it will honor your
523 This feature uses the readline library, so it will honor your
536 :file:`~/.inputrc` configuration (or whatever file your INPUTRC variable points
524 :file:`~/.inputrc` configuration (or whatever file your INPUTRC variable points
537 to). Adding the following lines to your :file:`.inputrc` file can make
525 to). Adding the following lines to your :file:`.inputrc` file can make
538 indenting/unindenting more convenient (M-i indents, M-u unindents)::
526 indenting/unindenting more convenient (M-i indents, M-u unindents)::
539
527
540 $if Python
528 $if Python
541 "\M-i": " "
529 "\M-i": " "
542 "\M-u": "\d\d\d\d"
530 "\M-u": "\d\d\d\d"
543 $endif
531 $endif
544
532
545 Note that there are 4 spaces between the quote marks after "M-i" above.
533 Note that there are 4 spaces between the quote marks after "M-i" above.
546
534
547 .. warning::
535 .. warning::
548
536
549 Setting the above indents will cause problems with unicode text entry in
537 Setting the above indents will cause problems with unicode text entry in
550 the terminal.
538 the terminal.
551
539
552 .. warning::
540 .. warning::
553
541
554 Autoindent is ON by default, but it can cause problems with the pasting of
542 Autoindent is ON by default, but it can cause problems with the pasting of
555 multi-line indented code (the pasted code gets re-indented on each line). A
543 multi-line indented code (the pasted code gets re-indented on each line). A
556 magic function %autoindent allows you to toggle it on/off at runtime. You
544 magic function %autoindent allows you to toggle it on/off at runtime. You
557 can also disable it permanently on in your :file:`ipython_config.py` file
545 can also disable it permanently on in your :file:`ipython_config.py` file
558 (set TerminalInteractiveShell.autoindent=False).
546 (set TerminalInteractiveShell.autoindent=False).
559
547
560 If you want to paste multiple lines, it is recommended that you use
548 If you want to paste multiple lines in the terminal, it is recommended that
561 ``%paste``.
549 you use ``%paste``.
562
550
563
551
564 Customizing readline behavior
552 Customizing readline behavior
565 +++++++++++++++++++++++++++++
553 +++++++++++++++++++++++++++++
566
554
567 All these features are based on the GNU readline library, which has an
555 All these features are based on the GNU readline library, which has an
568 extremely customizable interface. Normally, readline is configured via a
556 extremely customizable interface. Normally, readline is configured via a
569 file which defines the behavior of the library; the details of the
557 file which defines the behavior of the library; the details of the
570 syntax for this can be found in the readline documentation available
558 syntax for this can be found in the readline documentation available
571 with your system or on the Internet. IPython doesn't read this file (if
559 with your system or on the Internet. IPython doesn't read this file (if
572 it exists) directly, but it does support passing to readline valid
560 it exists) directly, but it does support passing to readline valid
573 options via a simple interface. In brief, you can customize readline by
561 options via a simple interface. In brief, you can customize readline by
574 setting the following options in your configuration file (note
562 setting the following options in your configuration file (note
575 that these options can not be specified at the command line):
563 that these options can not be specified at the command line):
576
564
577 * **readline_parse_and_bind**: this option can appear as many times as
565 * **readline_parse_and_bind**: this holds a list of strings to be executed
578 you want, each time defining a string to be executed via a
566 via a readline.parse_and_bind() command. The syntax for valid commands
579 readline.parse_and_bind() command. The syntax for valid commands
580 of this kind can be found by reading the documentation for the GNU
567 of this kind can be found by reading the documentation for the GNU
581 readline library, as these commands are of the kind which readline
568 readline library, as these commands are of the kind which readline
582 accepts in its configuration file.
569 accepts in its configuration file.
583 * **readline_remove_delims**: a string of characters to be removed
570 * **readline_remove_delims**: a string of characters to be removed
584 from the default word-delimiters list used by readline, so that
571 from the default word-delimiters list used by readline, so that
585 completions may be performed on strings which contain them. Do not
572 completions may be performed on strings which contain them. Do not
586 change the default value unless you know what you're doing.
573 change the default value unless you know what you're doing.
587 * **readline_omit__names**: when tab-completion is enabled, hitting
588 <tab> after a '.' in a name will complete all attributes of an
589 object, including all the special methods whose names include
590 double underscores (like __getitem__ or __class__). If you'd
591 rather not see these names by default, you can set this option to
592 1. Note that even when this option is set, you can still see those
593 names by explicitly typing a _ after the period and hitting <tab>:
594 'name._<tab>' will always complete attribute names starting with '_'.
595
596 This option is off by default so that new users see all
597 attributes of any objects they are dealing with.
598
574
599 You will find the default values in your configuration file.
575 You will find the default values in your configuration file.
600
576
601
577
602 Session logging and restoring
578 Session logging and restoring
603 -----------------------------
579 -----------------------------
604
580
605 You can log all input from a session either by starting IPython with the
581 You can log all input from a session either by starting IPython with the
606 command line switch ``--logfile=foo.py`` (see :ref:`here <command_line_options>`)
582 command line switch ``--logfile=foo.py`` (see :ref:`here <command_line_options>`)
607 or by activating the logging at any moment with the magic function %logstart.
583 or by activating the logging at any moment with the magic function %logstart.
608
584
609 Log files can later be reloaded by running them as scripts and IPython
585 Log files can later be reloaded by running them as scripts and IPython
610 will attempt to 'replay' the log by executing all the lines in it, thus
586 will attempt to 'replay' the log by executing all the lines in it, thus
611 restoring the state of a previous session. This feature is not quite
587 restoring the state of a previous session. This feature is not quite
612 perfect, but can still be useful in many cases.
588 perfect, but can still be useful in many cases.
613
589
614 The log files can also be used as a way to have a permanent record of
590 The log files can also be used as a way to have a permanent record of
615 any code you wrote while experimenting. Log files are regular text files
591 any code you wrote while experimenting. Log files are regular text files
616 which you can later open in your favorite text editor to extract code or
592 which you can later open in your favorite text editor to extract code or
617 to 'clean them up' before using them to replay a session.
593 to 'clean them up' before using them to replay a session.
618
594
619 The `%logstart` function for activating logging in mid-session is used as
595 The `%logstart` function for activating logging in mid-session is used as
620 follows::
596 follows::
621
597
622 %logstart [log_name [log_mode]]
598 %logstart [log_name [log_mode]]
623
599
624 If no name is given, it defaults to a file named 'ipython_log.py' in your
600 If no name is given, it defaults to a file named 'ipython_log.py' in your
625 current working directory, in 'rotate' mode (see below).
601 current working directory, in 'rotate' mode (see below).
626
602
627 '%logstart name' saves to file 'name' in 'backup' mode. It saves your
603 '%logstart name' saves to file 'name' in 'backup' mode. It saves your
628 history up to that point and then continues logging.
604 history up to that point and then continues logging.
629
605
630 %logstart takes a second optional parameter: logging mode. This can be
606 %logstart takes a second optional parameter: logging mode. This can be
631 one of (note that the modes are given unquoted):
607 one of (note that the modes are given unquoted):
632
608
633 * [over:] overwrite existing log_name.
609 * [over:] overwrite existing log_name.
634 * [backup:] rename (if exists) to log_name~ and start log_name.
610 * [backup:] rename (if exists) to log_name~ and start log_name.
635 * [append:] well, that says it.
611 * [append:] well, that says it.
636 * [rotate:] create rotating logs log_name.1~, log_name.2~, etc.
612 * [rotate:] create rotating logs log_name.1~, log_name.2~, etc.
637
613
638 The %logoff and %logon functions allow you to temporarily stop and
614 The %logoff and %logon functions allow you to temporarily stop and
639 resume logging to a file which had previously been started with
615 resume logging to a file which had previously been started with
640 %logstart. They will fail (with an explanation) if you try to use them
616 %logstart. They will fail (with an explanation) if you try to use them
641 before logging has been started.
617 before logging has been started.
642
618
643 .. _system_shell_access:
619 .. _system_shell_access:
644
620
645 System shell access
621 System shell access
646 -------------------
622 -------------------
647
623
648 Any input line beginning with a ! character is passed verbatim (minus
624 Any input line beginning with a ! character is passed verbatim (minus
649 the !, of course) to the underlying operating system. For example,
625 the !, of course) to the underlying operating system. For example,
650 typing ``!ls`` will run 'ls' in the current directory.
626 typing ``!ls`` will run 'ls' in the current directory.
651
627
652 Manual capture of command output
628 Manual capture of command output
653 --------------------------------
629 --------------------------------
654
630
655 You can assign the result of a system command to a Python variable with the
631 You can assign the result of a system command to a Python variable with the
656 syntax ``myfiles = !ls``. This gets machine readable output from stdout
632 syntax ``myfiles = !ls``. This gets machine readable output from stdout
657 (e.g. without colours), and splits on newlines. To explicitly get this sort of
633 (e.g. without colours), and splits on newlines. To explicitly get this sort of
658 output without assigning to a variable, use two exclamation marks (``!!ls``) or
634 output without assigning to a variable, use two exclamation marks (``!!ls``) or
659 the ``%sx`` magic command.
635 the ``%sx`` magic command.
660
636
661 The captured list has some convenience features. ``myfiles.n`` or ``myfiles.s``
637 The captured list has some convenience features. ``myfiles.n`` or ``myfiles.s``
662 returns a string delimited by newlines or spaces, respectively. ``myfiles.p``
638 returns a string delimited by newlines or spaces, respectively. ``myfiles.p``
663 produces `path objects <http://pypi.python.org/pypi/path.py>`_ from the list items.
639 produces `path objects <http://pypi.python.org/pypi/path.py>`_ from the list items.
664
640
665 IPython also allows you to expand the value of python variables when
641 IPython also allows you to expand the value of python variables when
666 making system calls. Wrap variables or expressions in {braces}::
642 making system calls. Wrap variables or expressions in {braces}::
667
643
668 In [1]: pyvar = 'Hello world'
644 In [1]: pyvar = 'Hello world'
669 In [2]: !echo "A python variable: {pyvar}"
645 In [2]: !echo "A python variable: {pyvar}"
670 A python variable: Hello world
646 A python variable: Hello world
671 In [3]: import math
647 In [3]: import math
672 In [4]: x = 8
648 In [4]: x = 8
673 In [5]: !echo {math.factorial(x)}
649 In [5]: !echo {math.factorial(x)}
674 40320
650 40320
675
651
676 For simple cases, you can alternatively prepend $ to a variable name::
652 For simple cases, you can alternatively prepend $ to a variable name::
677
653
678 In [6]: !echo $sys.argv
654 In [6]: !echo $sys.argv
679 [/home/fperez/usr/bin/ipython]
655 [/home/fperez/usr/bin/ipython]
680 In [7]: !echo "A system variable: $$HOME" # Use $$ for literal $
656 In [7]: !echo "A system variable: $$HOME" # Use $$ for literal $
681 A system variable: /home/fperez
657 A system variable: /home/fperez
682
658
683 System command aliases
659 System command aliases
684 ----------------------
660 ----------------------
685
661
686 The %alias magic function allows you to define magic functions which are in fact
662 The %alias magic function allows you to define magic functions which are in fact
687 system shell commands. These aliases can have parameters.
663 system shell commands. These aliases can have parameters.
688
664
689 ``%alias alias_name cmd`` defines 'alias_name' as an alias for 'cmd'
665 ``%alias alias_name cmd`` defines 'alias_name' as an alias for 'cmd'
690
666
691 Then, typing ``%alias_name params`` will execute the system command 'cmd
667 Then, typing ``alias_name params`` will execute the system command 'cmd
692 params' (from your underlying operating system).
668 params' (from your underlying operating system).
693
669
694 You can also define aliases with parameters using %s specifiers (one per
670 You can also define aliases with parameters using %s specifiers (one per
695 parameter). The following example defines the %parts function as an
671 parameter). The following example defines the parts function as an
696 alias to the command 'echo first %s second %s' where each %s will be
672 alias to the command 'echo first %s second %s' where each %s will be
697 replaced by a positional parameter to the call to %parts::
673 replaced by a positional parameter to the call to %parts::
698
674
699 In [1]: alias parts echo first %s second %s
675 In [1]: %alias parts echo first %s second %s
700 In [2]: %parts A B
676 In [2]: parts A B
701 first A second B
677 first A second B
702 In [3]: %parts A
678 In [3]: parts A
703 Incorrect number of arguments: 2 expected.
679 ERROR: Alias <parts> requires 2 arguments, 1 given.
704 parts is an alias to: 'echo first %s second %s'
705
680
706 If called with no parameters, %alias prints the table of currently
681 If called with no parameters, %alias prints the table of currently
707 defined aliases.
682 defined aliases.
708
683
709 The %rehashx magic allows you to load your entire $PATH as
684 The %rehashx magic allows you to load your entire $PATH as
710 ipython aliases. See its docstring for further details.
685 ipython aliases. See its docstring for further details.
711
686
712
687
713 .. _dreload:
688 .. _dreload:
714
689
715 Recursive reload
690 Recursive reload
716 ----------------
691 ----------------
717
692
718 The dreload function does a recursive reload of a module: changes made
693 The :mod:`IPython.lib.deepreload` module allows you to recursively reload a
719 to the module since you imported will actually be available without
694 module: changes made to any of its dependencies will be reloaded without
720 having to exit.
695 having to exit. To start using it, do::
696
697 from IPython.lib.deepreload import reload as dreload
721
698
722
699
723 Verbose and colored exception traceback printouts
700 Verbose and colored exception traceback printouts
724 -------------------------------------------------
701 -------------------------------------------------
725
702
726 IPython provides the option to see very detailed exception tracebacks,
703 IPython provides the option to see very detailed exception tracebacks,
727 which can be especially useful when debugging large programs. You can
704 which can be especially useful when debugging large programs. You can
728 run any Python file with the %run function to benefit from these
705 run any Python file with the %run function to benefit from these
729 detailed tracebacks. Furthermore, both normal and verbose tracebacks can
706 detailed tracebacks. Furthermore, both normal and verbose tracebacks can
730 be colored (if your terminal supports it) which makes them much easier
707 be colored (if your terminal supports it) which makes them much easier
731 to parse visually.
708 to parse visually.
732
709
733 See the magic xmode and colors functions for details (just type %magic).
710 See the magic xmode and colors functions for details (just type %magic).
734
711
735 These features are basically a terminal version of Ka-Ping Yee's cgitb
712 These features are basically a terminal version of Ka-Ping Yee's cgitb
736 module, now part of the standard Python library.
713 module, now part of the standard Python library.
737
714
738
715
739 .. _input_caching:
716 .. _input_caching:
740
717
741 Input caching system
718 Input caching system
742 --------------------
719 --------------------
743
720
744 IPython offers numbered prompts (In/Out) with input and output caching
721 IPython offers numbered prompts (In/Out) with input and output caching
745 (also referred to as 'input history'). All input is saved and can be
722 (also referred to as 'input history'). All input is saved and can be
746 retrieved as variables (besides the usual arrow key recall), in
723 retrieved as variables (besides the usual arrow key recall), in
747 addition to the %rep magic command that brings a history entry
724 addition to the %rep magic command that brings a history entry
748 up for editing on the next command line.
725 up for editing on the next command line.
749
726
750 The following GLOBAL variables always exist (so don't overwrite them!):
727 The following GLOBAL variables always exist (so don't overwrite them!):
751
728
752 * _i, _ii, _iii: store previous, next previous and next-next previous inputs.
729 * _i, _ii, _iii: store previous, next previous and next-next previous inputs.
753 * In, _ih : a list of all inputs; _ih[n] is the input from line n. If you
730 * In, _ih : a list of all inputs; _ih[n] is the input from line n. If you
754 overwrite In with a variable of your own, you can remake the assignment to the
731 overwrite In with a variable of your own, you can remake the assignment to the
755 internal list with a simple ``In=_ih``.
732 internal list with a simple ``In=_ih``.
756
733
757 Additionally, global variables named _i<n> are dynamically created (<n>
734 Additionally, global variables named _i<n> are dynamically created (<n>
758 being the prompt counter), so ``_i<n> == _ih[<n>] == In[<n>]``.
735 being the prompt counter), so ``_i<n> == _ih[<n>] == In[<n>]``.
759
736
760 For example, what you typed at prompt 14 is available as _i14, _ih[14]
737 For example, what you typed at prompt 14 is available as _i14, _ih[14]
761 and In[14].
738 and In[14].
762
739
763 This allows you to easily cut and paste multi line interactive prompts
740 This allows you to easily cut and paste multi line interactive prompts
764 by printing them out: they print like a clean string, without prompt
741 by printing them out: they print like a clean string, without prompt
765 characters. You can also manipulate them like regular variables (they
742 characters. You can also manipulate them like regular variables (they
766 are strings), modify or exec them (typing ``exec _i9`` will re-execute the
743 are strings), modify or exec them (typing ``exec _i9`` will re-execute the
767 contents of input prompt 9.
744 contents of input prompt 9.
768
745
769 You can also re-execute multiple lines of input easily by using the
746 You can also re-execute multiple lines of input easily by using the
770 magic %macro function (which automates the process and allows
747 magic %rerun or %macro functions. The macro system also allows you to re-execute
771 re-execution without having to type 'exec' every time). The macro system
748 previous lines which include magic function calls (which require special
772 also allows you to re-execute previous lines which include magic
749 processing). Type %macro? for more details on the macro system.
773 function calls (which require special processing). Type %macro? for more details
774 on the macro system.
775
750
776 A history function %hist allows you to see any part of your input
751 A history function %hist allows you to see any part of your input
777 history by printing a range of the _i variables.
752 history by printing a range of the _i variables.
778
753
779 You can also search ('grep') through your history by typing
754 You can also search ('grep') through your history by typing
780 ``%hist -g somestring``. This is handy for searching for URLs, IP addresses,
755 ``%hist -g somestring``. This is handy for searching for URLs, IP addresses,
781 etc. You can bring history entries listed by '%hist -g' up for editing
756 etc. You can bring history entries listed by '%hist -g' up for editing
782 with the %recall command, or run them immediately with %rerun.
757 with the %recall command, or run them immediately with %rerun.
783
758
784 .. _output_caching:
759 .. _output_caching:
785
760
786 Output caching system
761 Output caching system
787 ---------------------
762 ---------------------
788
763
789 For output that is returned from actions, a system similar to the input
764 For output that is returned from actions, a system similar to the input
790 cache exists but using _ instead of _i. Only actions that produce a
765 cache exists but using _ instead of _i. Only actions that produce a
791 result (NOT assignments, for example) are cached. If you are familiar
766 result (NOT assignments, for example) are cached. If you are familiar
792 with Mathematica, IPython's _ variables behave exactly like
767 with Mathematica, IPython's _ variables behave exactly like
793 Mathematica's % variables.
768 Mathematica's % variables.
794
769
795 The following GLOBAL variables always exist (so don't overwrite them!):
770 The following GLOBAL variables always exist (so don't overwrite them!):
796
771
797 * [_] (a single underscore) : stores previous output, like Python's
772 * [_] (a single underscore) : stores previous output, like Python's
798 default interpreter.
773 default interpreter.
799 * [__] (two underscores): next previous.
774 * [__] (two underscores): next previous.
800 * [___] (three underscores): next-next previous.
775 * [___] (three underscores): next-next previous.
801
776
802 Additionally, global variables named _<n> are dynamically created (<n>
777 Additionally, global variables named _<n> are dynamically created (<n>
803 being the prompt counter), such that the result of output <n> is always
778 being the prompt counter), such that the result of output <n> is always
804 available as _<n> (don't use the angle brackets, just the number, e.g.
779 available as _<n> (don't use the angle brackets, just the number, e.g.
805 _21).
780 _21).
806
781
807 These global variables are all stored in a global dictionary (not a
782 These variables are also stored in a global dictionary (not a
808 list, since it only has entries for lines which returned a result)
783 list, since it only has entries for lines which returned a result)
809 available under the names _oh and Out (similar to _ih and In). So the
784 available under the names _oh and Out (similar to _ih and In). So the
810 output from line 12 can be obtained as _12, Out[12] or _oh[12]. If you
785 output from line 12 can be obtained as _12, Out[12] or _oh[12]. If you
811 accidentally overwrite the Out variable you can recover it by typing
786 accidentally overwrite the Out variable you can recover it by typing
812 'Out=_oh' at the prompt.
787 'Out=_oh' at the prompt.
813
788
814 This system obviously can potentially put heavy memory demands on your
789 This system obviously can potentially put heavy memory demands on your
815 system, since it prevents Python's garbage collector from removing any
790 system, since it prevents Python's garbage collector from removing any
816 previously computed results. You can control how many results are kept
791 previously computed results. You can control how many results are kept
817 in memory with the option (at the command line or in your configuration
792 in memory with the option (at the command line or in your configuration
818 file) cache_size. If you set it to 0, the whole system is completely
793 file) cache_size. If you set it to 0, the whole system is completely
819 disabled and the prompts revert to the classic '>>>' of normal Python.
794 disabled and the prompts revert to the classic '>>>' of normal Python.
820
795
821
796
822 Directory history
797 Directory history
823 -----------------
798 -----------------
824
799
825 Your history of visited directories is kept in the global list _dh, and
800 Your history of visited directories is kept in the global list _dh, and
826 the magic %cd command can be used to go to any entry in that list. The
801 the magic %cd command can be used to go to any entry in that list. The
827 %dhist command allows you to view this history. Do ``cd -<TAB>`` to
802 %dhist command allows you to view this history. Do ``cd -<TAB>`` to
828 conveniently view the directory history.
803 conveniently view the directory history.
829
804
830
805
831 Automatic parentheses and quotes
806 Automatic parentheses and quotes
832 --------------------------------
807 --------------------------------
833
808
834 These features were adapted from Nathan Gray's LazyPython. They are
809 These features were adapted from Nathan Gray's LazyPython. They are
835 meant to allow less typing for common situations.
810 meant to allow less typing for common situations.
836
811
837
812
838 Automatic parentheses
813 Automatic parentheses
839 ---------------------
814 +++++++++++++++++++++
840
815
841 Callable objects (i.e. functions, methods, etc) can be invoked like this
816 Callable objects (i.e. functions, methods, etc) can be invoked like this
842 (notice the commas between the arguments)::
817 (notice the commas between the arguments)::
843
818
844 >>> callable_ob arg1, arg2, arg3
819 In [1]: callable_ob arg1, arg2, arg3
845
820 ------> callable_ob(arg1, arg2, arg3)
846 and the input will be translated to this::
847
848 -> callable_ob(arg1, arg2, arg3)
849
821
850 You can force automatic parentheses by using '/' as the first character
822 You can force automatic parentheses by using '/' as the first character
851 of a line. For example::
823 of a line. For example::
852
824
853 >>> /globals # becomes 'globals()'
825 In [2]: /globals # becomes 'globals()'
854
826
855 Note that the '/' MUST be the first character on the line! This won't work::
827 Note that the '/' MUST be the first character on the line! This won't work::
856
828
857 >>> print /globals # syntax error
829 In [3]: print /globals # syntax error
858
830
859 In most cases the automatic algorithm should work, so you should rarely
831 In most cases the automatic algorithm should work, so you should rarely
860 need to explicitly invoke /. One notable exception is if you are trying
832 need to explicitly invoke /. One notable exception is if you are trying
861 to call a function with a list of tuples as arguments (the parenthesis
833 to call a function with a list of tuples as arguments (the parenthesis
862 will confuse IPython)::
834 will confuse IPython)::
863
835
864 In [1]: zip (1,2,3),(4,5,6) # won't work
836 In [4]: zip (1,2,3),(4,5,6) # won't work
865
837
866 but this will work::
838 but this will work::
867
839
868 In [2]: /zip (1,2,3),(4,5,6)
840 In [5]: /zip (1,2,3),(4,5,6)
869 ---> zip ((1,2,3),(4,5,6))
841 ------> zip ((1,2,3),(4,5,6))
870 Out[2]= [(1, 4), (2, 5), (3, 6)]
842 Out[5]: [(1, 4), (2, 5), (3, 6)]
871
843
872 IPython tells you that it has altered your command line by displaying
844 IPython tells you that it has altered your command line by displaying
873 the new command line preceded by ->. e.g.::
845 the new command line preceded by ->. e.g.::
874
846
875 In [18]: callable list
847 In [6]: callable list
876 ----> callable (list)
848 ------> callable(list)
877
849
878
850
879 Automatic quoting
851 Automatic quoting
880 -----------------
852 +++++++++++++++++
881
853
882 You can force automatic quoting of a function's arguments by using ','
854 You can force automatic quoting of a function's arguments by using ','
883 or ';' as the first character of a line. For example::
855 or ';' as the first character of a line. For example::
884
856
885 >>> ,my_function /home/me # becomes my_function("/home/me")
857 In [1]: ,my_function /home/me # becomes my_function("/home/me")
886
858
887 If you use ';' instead, the whole argument is quoted as a single string
859 If you use ';' the whole argument is quoted as a single string, while ',' splits
888 (while ',' splits on whitespace)::
860 on whitespace::
889
861
890 >>> ,my_function a b c # becomes my_function("a","b","c")
862 In [2]: ,my_function a b c # becomes my_function("a","b","c")
891
863
892 >>> ;my_function a b c # becomes my_function("a b c")
864 In [3]: ;my_function a b c # becomes my_function("a b c")
893
865
894 Note that the ',' or ';' MUST be the first character on the line! This
866 Note that the ',' or ';' MUST be the first character on the line! This
895 won't work::
867 won't work::
896
868
897 >>> x = ,my_function /home/me # syntax error
869 In [4]: x = ,my_function /home/me # syntax error
898
870
899 IPython as your default Python environment
871 IPython as your default Python environment
900 ==========================================
872 ==========================================
901
873
902 Python honors the environment variable PYTHONSTARTUP and will execute at
874 Python honors the environment variable PYTHONSTARTUP and will execute at
903 startup the file referenced by this variable. If you put at the end of
875 startup the file referenced by this variable. If you put the following code at
904 this file the following two lines of code::
876 the end of that file, then IPython will be your working environment anytime you
877 start Python::
905
878
906 from IPython.frontend.terminal.ipapp import launch_new_instance
879 from IPython.frontend.terminal.ipapp import launch_new_instance
907 launch_new_instance()
880 launch_new_instance()
908 raise SystemExit
881 raise SystemExit
909
882
910 then IPython will be your working environment anytime you start Python.
911 The ``raise SystemExit`` is needed to exit Python when
883 The ``raise SystemExit`` is needed to exit Python when
912 it finishes, otherwise you'll be back at the normal Python '>>>'
884 it finishes, otherwise you'll be back at the normal Python '>>>'
913 prompt.
885 prompt.
914
886
915 This is probably useful to developers who manage multiple Python
887 This is probably useful to developers who manage multiple Python
916 versions and don't want to have correspondingly multiple IPython
888 versions and don't want to have correspondingly multiple IPython
917 versions. Note that in this mode, there is no way to pass IPython any
889 versions. Note that in this mode, there is no way to pass IPython any
918 command-line options, as those are trapped first by Python itself.
890 command-line options, as those are trapped first by Python itself.
919
891
920 .. _Embedding:
892 .. _Embedding:
921
893
922 Embedding IPython
894 Embedding IPython
923 =================
895 =================
924
896
925 It is possible to start an IPython instance inside your own Python
897 It is possible to start an IPython instance inside your own Python
926 programs. This allows you to evaluate dynamically the state of your
898 programs. This allows you to evaluate dynamically the state of your
927 code, operate with your variables, analyze them, etc. Note however that
899 code, operate with your variables, analyze them, etc. Note however that
928 any changes you make to values while in the shell do not propagate back
900 any changes you make to values while in the shell do not propagate back
929 to the running code, so it is safe to modify your values because you
901 to the running code, so it is safe to modify your values because you
930 won't break your code in bizarre ways by doing so.
902 won't break your code in bizarre ways by doing so.
931
903
904 .. note::
905
906 At present, trying to embed IPython from inside IPython causes problems. Run
907 the code samples below outside IPython.
908
932 This feature allows you to easily have a fully functional python
909 This feature allows you to easily have a fully functional python
933 environment for doing object introspection anywhere in your code with a
910 environment for doing object introspection anywhere in your code with a
934 simple function call. In some cases a simple print statement is enough,
911 simple function call. In some cases a simple print statement is enough,
935 but if you need to do more detailed analysis of a code fragment this
912 but if you need to do more detailed analysis of a code fragment this
936 feature can be very valuable.
913 feature can be very valuable.
937
914
938 It can also be useful in scientific computing situations where it is
915 It can also be useful in scientific computing situations where it is
939 common to need to do some automatic, computationally intensive part and
916 common to need to do some automatic, computationally intensive part and
940 then stop to look at data, plots, etc.
917 then stop to look at data, plots, etc.
941 Opening an IPython instance will give you full access to your data and
918 Opening an IPython instance will give you full access to your data and
942 functions, and you can resume program execution once you are done with
919 functions, and you can resume program execution once you are done with
943 the interactive part (perhaps to stop again later, as many times as
920 the interactive part (perhaps to stop again later, as many times as
944 needed).
921 needed).
945
922
946 The following code snippet is the bare minimum you need to include in
923 The following code snippet is the bare minimum you need to include in
947 your Python programs for this to work (detailed examples follow later)::
924 your Python programs for this to work (detailed examples follow later)::
948
925
949 from IPython import embed
926 from IPython import embed
950
927
951 embed() # this call anywhere in your program will start IPython
928 embed() # this call anywhere in your program will start IPython
952
929
953 You can run embedded instances even in code which is itself being run at
930 You can run embedded instances even in code which is itself being run at
954 the IPython interactive prompt with '%run <filename>'. Since it's easy
931 the IPython interactive prompt with '%run <filename>'. Since it's easy
955 to get lost as to where you are (in your top-level IPython or in your
932 to get lost as to where you are (in your top-level IPython or in your
956 embedded one), it's a good idea in such cases to set the in/out prompts
933 embedded one), it's a good idea in such cases to set the in/out prompts
957 to something different for the embedded instances. The code examples
934 to something different for the embedded instances. The code examples
958 below illustrate this.
935 below illustrate this.
959
936
960 You can also have multiple IPython instances in your program and open
937 You can also have multiple IPython instances in your program and open
961 them separately, for example with different options for data
938 them separately, for example with different options for data
962 presentation. If you close and open the same instance multiple times,
939 presentation. If you close and open the same instance multiple times,
963 its prompt counters simply continue from each execution to the next.
940 its prompt counters simply continue from each execution to the next.
964
941
965 Please look at the docstrings in the :mod:`~IPython.frontend.terminal.embed`
942 Please look at the docstrings in the :mod:`~IPython.frontend.terminal.embed`
966 module for more details on the use of this system.
943 module for more details on the use of this system.
967
944
968 The following sample file illustrating how to use the embedding
945 The following sample file illustrating how to use the embedding
969 functionality is provided in the examples directory as example-embed.py.
946 functionality is provided in the examples directory as example-embed.py.
970 It should be fairly self-explanatory:
947 It should be fairly self-explanatory:
971
948
972 .. literalinclude:: ../../examples/core/example-embed.py
949 .. literalinclude:: ../../examples/core/example-embed.py
973 :language: python
950 :language: python
974
951
975 Once you understand how the system functions, you can use the following
952 Once you understand how the system functions, you can use the following
976 code fragments in your programs which are ready for cut and paste:
953 code fragments in your programs which are ready for cut and paste:
977
954
978 .. literalinclude:: ../../examples/core/example-embed-short.py
955 .. literalinclude:: ../../examples/core/example-embed-short.py
979 :language: python
956 :language: python
980
957
981 Using the Python debugger (pdb)
958 Using the Python debugger (pdb)
982 ===============================
959 ===============================
983
960
984 Running entire programs via pdb
961 Running entire programs via pdb
985 -------------------------------
962 -------------------------------
986
963
987 pdb, the Python debugger, is a powerful interactive debugger which
964 pdb, the Python debugger, is a powerful interactive debugger which
988 allows you to step through code, set breakpoints, watch variables,
965 allows you to step through code, set breakpoints, watch variables,
989 etc. IPython makes it very easy to start any script under the control
966 etc. IPython makes it very easy to start any script under the control
990 of pdb, regardless of whether you have wrapped it into a 'main()'
967 of pdb, regardless of whether you have wrapped it into a 'main()'
991 function or not. For this, simply type '%run -d myscript' at an
968 function or not. For this, simply type '%run -d myscript' at an
992 IPython prompt. See the %run command's documentation (via '%run?' or
969 IPython prompt. See the %run command's documentation (via '%run?' or
993 in Sec. magic_ for more details, including how to control where pdb
970 in Sec. magic_ for more details, including how to control where pdb
994 will stop execution first.
971 will stop execution first.
995
972
996 For more information on the use of the pdb debugger, read the included
973 For more information on the use of the pdb debugger, read the included
997 pdb.doc file (part of the standard Python distribution). On a stock
974 pdb.doc file (part of the standard Python distribution). On a stock
998 Linux system it is located at /usr/lib/python2.3/pdb.doc, but the
975 Linux system it is located at /usr/lib/python2.3/pdb.doc, but the
999 easiest way to read it is by using the help() function of the pdb module
976 easiest way to read it is by using the help() function of the pdb module
1000 as follows (in an IPython prompt)::
977 as follows (in an IPython prompt)::
1001
978
1002 In [1]: import pdb
979 In [1]: import pdb
1003 In [2]: pdb.help()
980 In [2]: pdb.help()
1004
981
1005 This will load the pdb.doc document in a file viewer for you automatically.
982 This will load the pdb.doc document in a file viewer for you automatically.
1006
983
1007
984
1008 Automatic invocation of pdb on exceptions
985 Automatic invocation of pdb on exceptions
1009 -----------------------------------------
986 -----------------------------------------
1010
987
1011 IPython, if started with the -pdb option (or if the option is set in
988 IPython, if started with the ``--pdb`` option (or if the option is set in
1012 your rc file) can call the Python pdb debugger every time your code
989 your config file) can call the Python pdb debugger every time your code
1013 triggers an uncaught exception. This feature
990 triggers an uncaught exception. This feature
1014 can also be toggled at any time with the %pdb magic command. This can be
991 can also be toggled at any time with the %pdb magic command. This can be
1015 extremely useful in order to find the origin of subtle bugs, because pdb
992 extremely useful in order to find the origin of subtle bugs, because pdb
1016 opens up at the point in your code which triggered the exception, and
993 opens up at the point in your code which triggered the exception, and
1017 while your program is at this point 'dead', all the data is still
994 while your program is at this point 'dead', all the data is still
1018 available and you can walk up and down the stack frame and understand
995 available and you can walk up and down the stack frame and understand
1019 the origin of the problem.
996 the origin of the problem.
1020
997
1021 Furthermore, you can use these debugging facilities both with the
998 Furthermore, you can use these debugging facilities both with the
1022 embedded IPython mode and without IPython at all. For an embedded shell
999 embedded IPython mode and without IPython at all. For an embedded shell
1023 (see sec. Embedding_), simply call the constructor with
1000 (see sec. Embedding_), simply call the constructor with
1024 '--pdb' in the argument string and automatically pdb will be called if an
1001 ``--pdb`` in the argument string and pdb will automatically be called if an
1025 uncaught exception is triggered by your code.
1002 uncaught exception is triggered by your code.
1026
1003
1027 For stand-alone use of the feature in your programs which do not use
1004 For stand-alone use of the feature in your programs which do not use
1028 IPython at all, put the following lines toward the top of your 'main'
1005 IPython at all, put the following lines toward the top of your 'main'
1029 routine::
1006 routine::
1030
1007
1031 import sys
1008 import sys
1032 from IPython.core import ultratb
1009 from IPython.core import ultratb
1033 sys.excepthook = ultratb.FormattedTB(mode='Verbose',
1010 sys.excepthook = ultratb.FormattedTB(mode='Verbose',
1034 color_scheme='Linux', call_pdb=1)
1011 color_scheme='Linux', call_pdb=1)
1035
1012
1036 The mode keyword can be either 'Verbose' or 'Plain', giving either very
1013 The mode keyword can be either 'Verbose' or 'Plain', giving either very
1037 detailed or normal tracebacks respectively. The color_scheme keyword can
1014 detailed or normal tracebacks respectively. The color_scheme keyword can
1038 be one of 'NoColor', 'Linux' (default) or 'LightBG'. These are the same
1015 be one of 'NoColor', 'Linux' (default) or 'LightBG'. These are the same
1039 options which can be set in IPython with -colors and -xmode.
1016 options which can be set in IPython with ``--colors`` and ``--xmode``.
1040
1017
1041 This will give any of your programs detailed, colored tracebacks with
1018 This will give any of your programs detailed, colored tracebacks with
1042 automatic invocation of pdb.
1019 automatic invocation of pdb.
1043
1020
1044
1021
1045 Extensions for syntax processing
1022 Extensions for syntax processing
1046 ================================
1023 ================================
1047
1024
1048 This isn't for the faint of heart, because the potential for breaking
1025 This isn't for the faint of heart, because the potential for breaking
1049 things is quite high. But it can be a very powerful and useful feature.
1026 things is quite high. But it can be a very powerful and useful feature.
1050 In a nutshell, you can redefine the way IPython processes the user input
1027 In a nutshell, you can redefine the way IPython processes the user input
1051 line to accept new, special extensions to the syntax without needing to
1028 line to accept new, special extensions to the syntax without needing to
1052 change any of IPython's own code.
1029 change any of IPython's own code.
1053
1030
1054 In the IPython/extensions directory you will find some examples
1031 In the IPython/extensions directory you will find some examples
1055 supplied, which we will briefly describe now. These can be used 'as is'
1032 supplied, which we will briefly describe now. These can be used 'as is'
1056 (and both provide very useful functionality), or you can use them as a
1033 (and both provide very useful functionality), or you can use them as a
1057 starting point for writing your own extensions.
1034 starting point for writing your own extensions.
1058
1035
1059 .. _pasting_with_prompts:
1036 .. _pasting_with_prompts:
1060
1037
1061 Pasting of code starting with Python or IPython prompts
1038 Pasting of code starting with Python or IPython prompts
1062 -------------------------------------------------------
1039 -------------------------------------------------------
1063
1040
1064 IPython is smart enough to filter out input prompts, be they plain Python ones
1041 IPython is smart enough to filter out input prompts, be they plain Python ones
1065 (``>>>`` and ``...``) or IPython ones (``In [N]:`` and `` ...:``). You can
1042 (``>>>`` and ``...``) or IPython ones (``In [N]:`` and `` ...:``). You can
1066 therefore copy and paste from existing interactive sessions without worry.
1043 therefore copy and paste from existing interactive sessions without worry.
1067
1044
1068 The following is a 'screenshot' of how things work, copying an example from the
1045 The following is a 'screenshot' of how things work, copying an example from the
1069 standard Python tutorial::
1046 standard Python tutorial::
1070
1047
1071 In [1]: >>> # Fibonacci series:
1048 In [1]: >>> # Fibonacci series:
1072
1049
1073 In [2]: ... # the sum of two elements defines the next
1050 In [2]: ... # the sum of two elements defines the next
1074
1051
1075 In [3]: ... a, b = 0, 1
1052 In [3]: ... a, b = 0, 1
1076
1053
1077 In [4]: >>> while b < 10:
1054 In [4]: >>> while b < 10:
1078 ...: ... print b
1055 ...: ... print b
1079 ...: ... a, b = b, a+b
1056 ...: ... a, b = b, a+b
1080 ...:
1057 ...:
1081 1
1058 1
1082 1
1059 1
1083 2
1060 2
1084 3
1061 3
1085 5
1062 5
1086 8
1063 8
1087
1064
1088 And pasting from IPython sessions works equally well::
1065 And pasting from IPython sessions works equally well::
1089
1066
1090 In [1]: In [5]: def f(x):
1067 In [1]: In [5]: def f(x):
1091 ...: ...: "A simple function"
1068 ...: ...: "A simple function"
1092 ...: ...: return x**2
1069 ...: ...: return x**2
1093 ...: ...:
1070 ...: ...:
1094
1071
1095 In [2]: f(3)
1072 In [2]: f(3)
1096 Out[2]: 9
1073 Out[2]: 9
1097
1074
1098 .. _gui_support:
1075 .. _gui_support:
1099
1076
1100 GUI event loop support
1077 GUI event loop support
1101 ======================
1078 ======================
1102
1079
1103 .. versionadded:: 0.11
1080 .. versionadded:: 0.11
1104 The ``%gui`` magic and :mod:`IPython.lib.inputhook`.
1081 The ``%gui`` magic and :mod:`IPython.lib.inputhook`.
1105
1082
1106 IPython has excellent support for working interactively with Graphical User
1083 IPython has excellent support for working interactively with Graphical User
1107 Interface (GUI) toolkits, such as wxPython, PyQt4/PySide, PyGTK and Tk. This is
1084 Interface (GUI) toolkits, such as wxPython, PyQt4/PySide, PyGTK and Tk. This is
1108 implemented using Python's builtin ``PyOSInputHook`` hook. This implementation
1085 implemented using Python's builtin ``PyOSInputHook`` hook. This implementation
1109 is extremely robust compared to our previous thread-based version. The
1086 is extremely robust compared to our previous thread-based version. The
1110 advantages of this are:
1087 advantages of this are:
1111
1088
1112 * GUIs can be enabled and disabled dynamically at runtime.
1089 * GUIs can be enabled and disabled dynamically at runtime.
1113 * The active GUI can be switched dynamically at runtime.
1090 * The active GUI can be switched dynamically at runtime.
1114 * In some cases, multiple GUIs can run simultaneously with no problems.
1091 * In some cases, multiple GUIs can run simultaneously with no problems.
1115 * There is a developer API in :mod:`IPython.lib.inputhook` for customizing
1092 * There is a developer API in :mod:`IPython.lib.inputhook` for customizing
1116 all of these things.
1093 all of these things.
1117
1094
1118 For users, enabling GUI event loop integration is simple. You simple use the
1095 For users, enabling GUI event loop integration is simple. You simple use the
1119 ``%gui`` magic as follows::
1096 ``%gui`` magic as follows::
1120
1097
1121 %gui [GUINAME]
1098 %gui [GUINAME]
1122
1099
1123 With no arguments, ``%gui`` removes all GUI support. Valid ``GUINAME``
1100 With no arguments, ``%gui`` removes all GUI support. Valid ``GUINAME``
1124 arguments are ``wx``, ``qt``, ``gtk`` and ``tk``.
1101 arguments are ``wx``, ``qt``, ``gtk`` and ``tk``.
1125
1102
1126 Thus, to use wxPython interactively and create a running :class:`wx.App`
1103 Thus, to use wxPython interactively and create a running :class:`wx.App`
1127 object, do::
1104 object, do::
1128
1105
1129 %gui wx
1106 %gui wx
1130
1107
1131 For information on IPython's Matplotlib integration (and the ``pylab`` mode)
1108 For information on IPython's Matplotlib integration (and the ``pylab`` mode)
1132 see :ref:`this section <matplotlib_support>`.
1109 see :ref:`this section <matplotlib_support>`.
1133
1110
1134 For developers that want to use IPython's GUI event loop integration in the
1111 For developers that want to use IPython's GUI event loop integration in the
1135 form of a library, these capabilities are exposed in library form in the
1112 form of a library, these capabilities are exposed in library form in the
1136 :mod:`IPython.lib.inputhook` and :mod:`IPython.lib.guisupport` modules.
1113 :mod:`IPython.lib.inputhook` and :mod:`IPython.lib.guisupport` modules.
1137 Interested developers should see the module docstrings for more information,
1114 Interested developers should see the module docstrings for more information,
1138 but there are a few points that should be mentioned here.
1115 but there are a few points that should be mentioned here.
1139
1116
1140 First, the ``PyOSInputHook`` approach only works in command line settings
1117 First, the ``PyOSInputHook`` approach only works in command line settings
1141 where readline is activated. The integration with various eventloops
1118 where readline is activated. The integration with various eventloops
1142 is handled somewhat differently (and more simply) when using the standalone
1119 is handled somewhat differently (and more simply) when using the standalone
1143 kernel, as in the qtconsole and notebook.
1120 kernel, as in the qtconsole and notebook.
1144
1121
1145 Second, when using the ``PyOSInputHook`` approach, a GUI application should
1122 Second, when using the ``PyOSInputHook`` approach, a GUI application should
1146 *not* start its event loop. Instead all of this is handled by the
1123 *not* start its event loop. Instead all of this is handled by the
1147 ``PyOSInputHook``. This means that applications that are meant to be used both
1124 ``PyOSInputHook``. This means that applications that are meant to be used both
1148 in IPython and as standalone apps need to have special code to detects how the
1125 in IPython and as standalone apps need to have special code to detects how the
1149 application is being run. We highly recommend using IPython's support for this.
1126 application is being run. We highly recommend using IPython's support for this.
1150 Since the details vary slightly between toolkits, we point you to the various
1127 Since the details vary slightly between toolkits, we point you to the various
1151 examples in our source directory :file:`docs/examples/lib` that demonstrate
1128 examples in our source directory :file:`docs/examples/lib` that demonstrate
1152 these capabilities.
1129 these capabilities.
1153
1130
1154 .. warning::
1131 .. warning::
1155
1132
1156 The WX version of this is currently broken. While ``--pylab=wx`` works
1133 The WX version of this is currently broken. While ``--pylab=wx`` works
1157 fine, standalone WX apps do not. See
1134 fine, standalone WX apps do not. See
1158 https://github.com/ipython/ipython/issues/645 for details of our progress on
1135 https://github.com/ipython/ipython/issues/645 for details of our progress on
1159 this issue.
1136 this issue.
1160
1137
1161
1138
1162 Third, unlike previous versions of IPython, we no longer "hijack" (replace
1139 Third, unlike previous versions of IPython, we no longer "hijack" (replace
1163 them with no-ops) the event loops. This is done to allow applications that
1140 them with no-ops) the event loops. This is done to allow applications that
1164 actually need to run the real event loops to do so. This is often needed to
1141 actually need to run the real event loops to do so. This is often needed to
1165 process pending events at critical points.
1142 process pending events at critical points.
1166
1143
1167 Finally, we also have a number of examples in our source directory
1144 Finally, we also have a number of examples in our source directory
1168 :file:`docs/examples/lib` that demonstrate these capabilities.
1145 :file:`docs/examples/lib` that demonstrate these capabilities.
1169
1146
1170 PyQt and PySide
1147 PyQt and PySide
1171 ---------------
1148 ---------------
1172
1149
1173 .. attempt at explanation of the complete mess that is Qt support
1150 .. attempt at explanation of the complete mess that is Qt support
1174
1151
1175 When you use ``--gui=qt`` or ``--pylab=qt``, IPython can work with either
1152 When you use ``--gui=qt`` or ``--pylab=qt``, IPython can work with either
1176 PyQt4 or PySide. There are three options for configuration here, because
1153 PyQt4 or PySide. There are three options for configuration here, because
1177 PyQt4 has two APIs for QString and QVariant - v1, which is the default on
1154 PyQt4 has two APIs for QString and QVariant - v1, which is the default on
1178 Python 2, and the more natural v2, which is the only API supported by PySide.
1155 Python 2, and the more natural v2, which is the only API supported by PySide.
1179 v2 is also the default for PyQt4 on Python 3. IPython's code for the QtConsole
1156 v2 is also the default for PyQt4 on Python 3. IPython's code for the QtConsole
1180 uses v2, but you can still use any interface in your code, since the
1157 uses v2, but you can still use any interface in your code, since the
1181 Qt frontend is in a different process.
1158 Qt frontend is in a different process.
1182
1159
1183 The default will be to import PyQt4 without configuration of the APIs, thus
1160 The default will be to import PyQt4 without configuration of the APIs, thus
1184 matching what most applications would expect. It will fall back of PySide if
1161 matching what most applications would expect. It will fall back of PySide if
1185 PyQt4 is unavailable.
1162 PyQt4 is unavailable.
1186
1163
1187 If specified, IPython will respect the environment variable ``QT_API`` used
1164 If specified, IPython will respect the environment variable ``QT_API`` used
1188 by ETS. ETS 4.0 also works with both PyQt4 and PySide, but it requires
1165 by ETS. ETS 4.0 also works with both PyQt4 and PySide, but it requires
1189 PyQt4 to use its v2 API. So if ``QT_API=pyside`` PySide will be used,
1166 PyQt4 to use its v2 API. So if ``QT_API=pyside`` PySide will be used,
1190 and if ``QT_API=pyqt`` then PyQt4 will be used *with the v2 API* for
1167 and if ``QT_API=pyqt`` then PyQt4 will be used *with the v2 API* for
1191 QString and QVariant, so ETS codes like MayaVi will also work with IPython.
1168 QString and QVariant, so ETS codes like MayaVi will also work with IPython.
1192
1169
1193 If you launch IPython in pylab mode with ``ipython --pylab=qt``, then IPython
1170 If you launch IPython in pylab mode with ``ipython --pylab=qt``, then IPython
1194 will ask matplotlib which Qt library to use (only if QT_API is *not set*), via
1171 will ask matplotlib which Qt library to use (only if QT_API is *not set*), via
1195 the 'backend.qt4' rcParam. If matplotlib is version 1.0.1 or older, then
1172 the 'backend.qt4' rcParam. If matplotlib is version 1.0.1 or older, then
1196 IPython will always use PyQt4 without setting the v2 APIs, since neither v2
1173 IPython will always use PyQt4 without setting the v2 APIs, since neither v2
1197 PyQt nor PySide work.
1174 PyQt nor PySide work.
1198
1175
1199 .. warning::
1176 .. warning::
1200
1177
1201 Note that this means for ETS 4 to work with PyQt4, ``QT_API`` *must* be set
1178 Note that this means for ETS 4 to work with PyQt4, ``QT_API`` *must* be set
1202 to work with IPython's qt integration, because otherwise PyQt4 will be
1179 to work with IPython's qt integration, because otherwise PyQt4 will be
1203 loaded in an incompatible mode.
1180 loaded in an incompatible mode.
1204
1181
1205 It also means that you must *not* have ``QT_API`` set if you want to
1182 It also means that you must *not* have ``QT_API`` set if you want to
1206 use ``--gui=qt`` with code that requires PyQt4 API v1.
1183 use ``--gui=qt`` with code that requires PyQt4 API v1.
1207
1184
1208
1185
1209 .. _matplotlib_support:
1186 .. _matplotlib_support:
1210
1187
1211 Plotting with matplotlib
1188 Plotting with matplotlib
1212 ========================
1189 ========================
1213
1190
1214 `Matplotlib`_ provides high quality 2D and 3D plotting for Python. Matplotlib
1191 `Matplotlib`_ provides high quality 2D and 3D plotting for Python. Matplotlib
1215 can produce plots on screen using a variety of GUI toolkits, including Tk,
1192 can produce plots on screen using a variety of GUI toolkits, including Tk,
1216 PyGTK, PyQt4 and wxPython. It also provides a number of commands useful for
1193 PyGTK, PyQt4 and wxPython. It also provides a number of commands useful for
1217 scientific computing, all with a syntax compatible with that of the popular
1194 scientific computing, all with a syntax compatible with that of the popular
1218 Matlab program.
1195 Matlab program.
1219
1196
1220 To start IPython with matplotlib support, use the ``--pylab`` switch. If no
1197 To start IPython with matplotlib support, use the ``--pylab`` switch. If no
1221 arguments are given, IPython will automatically detect your choice of
1198 arguments are given, IPython will automatically detect your choice of
1222 matplotlib backend. You can also request a specific backend with
1199 matplotlib backend. You can also request a specific backend with
1223 ``--pylab=backend``, where ``backend`` must be one of: 'tk', 'qt', 'wx', 'gtk',
1200 ``--pylab=backend``, where ``backend`` must be one of: 'tk', 'qt', 'wx', 'gtk',
1224 'osx'.
1201 'osx'.
1225
1202
1226 .. _Matplotlib: http://matplotlib.sourceforge.net
1203 .. _Matplotlib: http://matplotlib.sourceforge.net
1227
1204
1228 .. _interactive_demos:
1205 .. _interactive_demos:
1229
1206
1230 Interactive demos with IPython
1207 Interactive demos with IPython
1231 ==============================
1208 ==============================
1232
1209
1233 IPython ships with a basic system for running scripts interactively in
1210 IPython ships with a basic system for running scripts interactively in
1234 sections, useful when presenting code to audiences. A few tags embedded
1211 sections, useful when presenting code to audiences. A few tags embedded
1235 in comments (so that the script remains valid Python code) divide a file
1212 in comments (so that the script remains valid Python code) divide a file
1236 into separate blocks, and the demo can be run one block at a time, with
1213 into separate blocks, and the demo can be run one block at a time, with
1237 IPython printing (with syntax highlighting) the block before executing
1214 IPython printing (with syntax highlighting) the block before executing
1238 it, and returning to the interactive prompt after each block. The
1215 it, and returning to the interactive prompt after each block. The
1239 interactive namespace is updated after each block is run with the
1216 interactive namespace is updated after each block is run with the
1240 contents of the demo's namespace.
1217 contents of the demo's namespace.
1241
1218
1242 This allows you to show a piece of code, run it and then execute
1219 This allows you to show a piece of code, run it and then execute
1243 interactively commands based on the variables just created. Once you
1220 interactively commands based on the variables just created. Once you
1244 want to continue, you simply execute the next block of the demo. The
1221 want to continue, you simply execute the next block of the demo. The
1245 following listing shows the markup necessary for dividing a script into
1222 following listing shows the markup necessary for dividing a script into
1246 sections for execution as a demo:
1223 sections for execution as a demo:
1247
1224
1248 .. literalinclude:: ../../examples/lib/example-demo.py
1225 .. literalinclude:: ../../examples/lib/example-demo.py
1249 :language: python
1226 :language: python
1250
1227
1251 In order to run a file as a demo, you must first make a Demo object out
1228 In order to run a file as a demo, you must first make a Demo object out
1252 of it. If the file is named myscript.py, the following code will make a
1229 of it. If the file is named myscript.py, the following code will make a
1253 demo::
1230 demo::
1254
1231
1255 from IPython.lib.demo import Demo
1232 from IPython.lib.demo import Demo
1256
1233
1257 mydemo = Demo('myscript.py')
1234 mydemo = Demo('myscript.py')
1258
1235
1259 This creates the mydemo object, whose blocks you run one at a time by
1236 This creates the mydemo object, whose blocks you run one at a time by
1260 simply calling the object with no arguments. If you have autocall active
1237 simply calling the object with no arguments. If you have autocall active
1261 in IPython (the default), all you need to do is type::
1238 in IPython (the default), all you need to do is type::
1262
1239
1263 mydemo
1240 mydemo
1264
1241
1265 and IPython will call it, executing each block. Demo objects can be
1242 and IPython will call it, executing each block. Demo objects can be
1266 restarted, you can move forward or back skipping blocks, re-execute the
1243 restarted, you can move forward or back skipping blocks, re-execute the
1267 last block, etc. Simply use the Tab key on a demo object to see its
1244 last block, etc. Simply use the Tab key on a demo object to see its
1268 methods, and call '?' on them to see their docstrings for more usage
1245 methods, and call '?' on them to see their docstrings for more usage
1269 details. In addition, the demo module itself contains a comprehensive
1246 details. In addition, the demo module itself contains a comprehensive
1270 docstring, which you can access via::
1247 docstring, which you can access via::
1271
1248
1272 from IPython.lib import demo
1249 from IPython.lib import demo
1273
1250
1274 demo?
1251 demo?
1275
1252
1276 Limitations: It is important to note that these demos are limited to
1253 Limitations: It is important to note that these demos are limited to
1277 fairly simple uses. In particular, you can not put division marks in
1254 fairly simple uses. In particular, you cannot break up sections within
1278 indented code (loops, if statements, function definitions, etc.)
1255 indented code (loops, if statements, function definitions, etc.)
1279 Supporting something like this would basically require tracking the
1256 Supporting something like this would basically require tracking the
1280 internal execution state of the Python interpreter, so only top-level
1257 internal execution state of the Python interpreter, so only top-level
1281 divisions are allowed. If you want to be able to open an IPython
1258 divisions are allowed. If you want to be able to open an IPython
1282 instance at an arbitrary point in a program, you can use IPython's
1259 instance at an arbitrary point in a program, you can use IPython's
1283 embedding facilities, see :func:`IPython.embed` for details.
1260 embedding facilities, see :func:`IPython.embed` for details.
1284
1261
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