diff --git a/docs/source/interactive/htmlnotebook.txt b/docs/source/interactive/htmlnotebook.txt index 501d3a7..b695b08 100644 --- a/docs/source/interactive/htmlnotebook.txt +++ b/docs/source/interactive/htmlnotebook.txt @@ -1,198 +1,238 @@ .. _htmlnotebook: -========================= -An HTML Notebook IPython -========================= +The IPython Notebook +==================== + +The IPython Notebook is part of the IPython package, which aims to provide a +powerful, interactive approach to scientific computation. +The IPython Notebook extends the previous text-console-based approach, and the +later Qt console, in a qualitatively new diretion, providing a web-based +application suitable for capturing the whole scientific computation process. .. seealso:: :ref:`Installation requirements ` for the Notebook. -The IPython Notebook consists of two related components: -* An JSON based Notebook document format for recording and distributing - Python code and rich text. -* A web-based user interface for authoring and running notebook documents. +Basic structure +--------------- -The Notebook can be used by starting the Notebook server with the -command:: +The IPython Notebook combines two components: - $ ipython notebook +* **The IPython Notebook web application**: -Note that by default, the notebook doesn't load pylab, it's just a normal -IPython session like any other. If you want pylab support, you must use:: - - $ ipython notebook --pylab + The *IPython Notebook web app* is a browser-based tool for interactive + authoring of literate computations, in which explanatory text, mathematics, + computations and rich media output may be combined. Input and output are + stored in persistent cells that may be edited in-place. -which will behave similar to the terminal and Qt console versions, using your -default matplotlib backend and providing floating interactive plot windows. If -you want inline figures, you must manually select the ``inline`` backend:: +* **Notebook documents**: - $ ipython notebook --pylab inline + *Notebook documents*, or *notebooks*, are plain text documents which record + all inputs and outputs of the computations, interspersed with text, + mathematics and HTML 5 representations of objects, in a literate style. -This server uses the same ZeroMQ-based two process kernel architecture as -the QT Console as well Tornado for serving HTTP/S requests. Some of the main -features of the Notebook include: +Since the similarity in names can lead to some confusion, in this documentation +we will use capitalization of the word "notebook" to distinguish the +*N*otebook app and *n*otebook documents, thinking of the Notebook app as being +a proper noun. We will also always refer to the "Notebook app" when we are +referring to the browser-based interface, and usually to "notebook documents", +instead of "notebooks", for added precision. -* Display rich data (png/html/latex/svg) in the browser as a result of - computations. -* Compose text cells using HTML and Markdown. -* Import and export notebook documents in range of formats (.ipynb, .py). -* In browser syntax highlighting, tab completion and autoindentation. -* Inline matplotlib plots that can be stored in Notebook documents and opened - later. +We refer to the current state of the computational process taking place in the +Notebook app, i.e. the (numbered) sequence of input and output cells, as the +*notebook space*. Notebook documents provide an *exact*, *one-to-one* record +of all the content in the notebook space, as a plain text file in JSON format. +The Notebook app automatically saves, at certain intervals, the contents of +the notebook space to a notebook document stored on disk, with the same name +as the title of the notebook space, and the file extension ``.ipynb``. For +this reason, there is no confusion about using the same word "notebook" for +both the notebook space and the corresonding notebook document, since they are +really one and the same concept (we could say that they are "isomorphic"). -See :ref:`our installation documentation ` for directions on -how to install the notebook and its dependencies. -.. note:: +Main features of the IPython Notebook web app +--------------------------------------------- - You can start more than one notebook server at the same time, if you want to - work on notebooks in different directories. By default the first notebook - server starts in port 8888, later notebooks search for random ports near - that one. You can also manually specify the port with the ``--port`` - option. - +The main features of the IPython Notebook app include: -Basic Usage -=========== +* In-browser editing for code, with automatic syntax highlighting and indentation and tab completion/introspection. -The landing page of the notebook server application, which we call the IPython -Notebook *dashboard*, shows the notebooks currently available in the directory -in which the application was started, and allows you to create new notebooks. +* Literate combination of code with rich text using the Markdown_ markup language. -A notebook is a combination of two things: +* Mathematics is easily included within the Markdown using LaTeX notation, and rendered natively by MathJax_. -1. An interactive session connected to an IPython kernel, controlled by a web - application that can send input to the console and display many types of - output (text, graphics, mathematics and more). This is the same kernel used - by the :ref:`Qt console `, but in this case the web console sends - input in persistent cells that you can edit in-place instead of the - vertically scrolling terminal style used by the Qt console. +* Displays rich data representations (e.g. HTML / LaTeX / SVG) as the result of computations. -2. A document that can save the inputs and outputs of the session as well as - additional text that accompanies the code but is not meant for execution. - In this way, notebook files serve as a complete computational record of a - session including explanatory text and mathematics, code and resulting - figures. These documents are internally JSON files and are saved with the - ``.ipynb`` extension. +* Publication-quality figures in a range of formats (SVG / PNG), rendered by the matplotlib_ library, may be included inline and exported. -If you have ever used the Mathematica or Sage notebooks (the latter is also -web-based__) you should feel right at home. If you have not, you should be -able to learn how to use it in just a few minutes. -.. __: http://sagenb.org +.. _MathJax: http://www.mathjax.org/ +.. _matplotlib: http://matplotlib.org/ +.. _Markdown: http://daringfireball.net/projects/markdown/syntax -Creating and editing notebooks ------------------------------- +Notebook documents +------------------ -You can create new notebooks from the dashboard with the ``New Notebook`` -button or open existing ones by clicking on their name. Once in a notebook, -your browser tab will reflect the name of that notebook (prefixed with "IPy:"). -The URL for that notebook is not meant to be human-readable and is *not* -persistent across invocations of the notebook server. - -You can also drag and drop into the area listing files any python file: it -will be imported into a notebook with the same name (but ``.ipynb`` extension) -located in the directory where the notebook server was started. This notebook -will consist of a single cell with all the code in the file, which you can -later manually partition into individual cells for gradual execution, add text -and graphics, etc. - - -Workflow and limitations ------------------------- - -The normal workflow in a notebook is quite similar to a normal IPython session, -with the difference that you can edit a cell in-place multiple times until you -obtain the desired results rather than having to rerun separate scripts with -the ``%run`` magic (though magics also work in the notebook). Typically -you'll work on a problem in pieces, organizing related pieces into cells and -moving forward as previous parts work correctly. This is much more convenient -for interactive exploration than breaking up a computation into scripts that -must be executed together, especially if parts of them take a long time to run -(In the traditional terminal-based IPython, you can use tricks with namespaces -and ``%run -i`` to achieve this capability, but we think the notebook is a more -natural solution for that kind of problem). - -The only significant limitation the notebook currently has, compared to the qt -console, is that it can not run any code that expects input from the kernel -(such as scripts that call :func:`raw_input`). Very importantly, this means -that the ``%debug`` magic does *not* work in the notebook! We intend to -correct this limitation, but in the meantime, there is a way to debug problems -in the notebook: you can attach a Qt console to your existing notebook kernel, -and run ``%debug`` from the Qt console. If your notebook is running on a local -computer (i.e. if you are accessing it via your localhost address at -127.0.0.1), you can just type ``%qtconsole`` in the notebook and a Qt console -will open up connected to that same kernel. - -In general, the notebook server prints the full details of how to connect to -each kernel at the terminal, with lines like:: +Notebook document files are just standard, ASCII-coded text files with the extension ``.ipynb``, stored in the working directory on your computer. Since the contents of the files are just plain text, they can be easily version-controlled and shared with colleagues. - [IPKernelApp] To connect another client to this kernel, use: - [IPKernelApp] --existing kernel-3bb93edd-6b5a-455c-99c8-3b658f45dde5.json +Internally, notebook document files use the JSON_ format, allowing them to +store a *complete*, *reproducible*, *one-to-one* copy of the state of the computational state as it is inside the Notebook app. +All computations carried out, and the corresponding results obtained, can be +combined in a literate way, interleaving executable code with rich text, mathematics, and HTML 5 representations of objects. -This is the name of a JSON file that contains all the port and validation -information necessary to connect to the kernel. You can manually start a -qt console with:: +.. _JSON: http://en.wikipedia.org/wiki/JSON - ipython qtconsole --existing kernel-3bb93edd-6b5a-455c-99c8-3b658f45dde5.json +Notebooks may easily be exported to a range of static formats, including +HTML (for example, for blog posts), PDF and slide shows, via the newly-included `nbconvert script`_ functionality. -and if you only have a single kernel running, simply typing:: +Furthermore, any ``.ipynb`` notebook document with a publicly-available URL can be shared via the `IPython Notebook Viewer`_ service. This service loads the notebook document from the URL which will +provide it as a static web page. The results may thus be shared with a colleague, or as a public blog post, without other users needing to install IPython themselves. - ipython qtconsole --existing +See the :ref:`installation documentation ` for directions on +how to install the notebook and its dependencies. -will automatically find it (it will always find the most recently started -kernel if there is more than one). You can also request this connection data -by typing ``%connect_info``; this will print the same file information as well -as the content of the JSON data structure it contains. +.. _`Ipython Notebook Viewer`: http://nbviewer.ipython.org + +.. note:: + + You can start more than one notebook server at the same time, if you want to + work on notebooks in different directories. By default the first notebook + server starts on port 8888, and later notebook servers search for ports + near that one. You can also manually specify the port with the ``--port`` + option. + + +Starting up the IPython Notebook web app +---------------------------------------- + +You can start running the Notebook web app using the following command:: + + $ ipython notebook + +(Here, and in the sequel, the initial ``$`` represents the shell prompt, indicating that the command is to be run from the command line in a shell.) + +The landing page of the notebook server application, the *dashboard*, shows +the notebooks currently available in the *working directory* (the directory +from which the notebook was started). +You can create new notebooks from the dashboard with the ``New Notebook`` +button, or open existing ones by clicking on their name. +You can also drag and drop ``.ipynb`` notebooks and standard ``.py`` Python +source code files into the notebook list area. + +``.py`` files will be imported into the IPython Notebook as a notebook with +the same name, but an ``.ipynb`` extension, located in the working directory. +The notebook created will have just one cell, which will contain all the +code in the ``.py`` file. You can later manually partition this into +individual cells using the ``Edit | Split Cell`` menu option, or the +:kbd:`Ctrl-m -` keyboard shortcut. + +.. Alternatively, prior to importing the ``.py``, you can manually add ``# < +nbformat>2`` at the start of the file, and then add separators for +text and code cells, to get a cleaner import with the file already broken into +individual cells. + +When you open or create a new notebook, your browser tab will reflect the name +of that notebook, prefixed by the "IPy" icon denoting that the tab corresponds to the IPython Notebook. +The URL is currently not meant to be human-readable and is not persistent +across invocations of the notebook server; however, this will change in a +future version of IPython. + + +The IPython Notebook web app is based on a server-client structure. +This server uses a two-process kernel architecture based on ZeroMQ, as well as +Tornado for serving HTTP requests. Other clients may connect to the same +underlying IPython kernel; see below. + + +Notebook user interface +----------------------- + +When you open a new notebook document in the Notebook, you will be presented +with the title associated to the notebook space/document, a *menu bar*, a +*toolbar* and an empty *input cell*. + +Notebook title +~~~~~~~~~~~~~~ +The title of the notebook document that is currently being edited is displayed +at the top of the page, next to the ``IP[y]: Notebook`` logo. This title may +be edited directly by clicking on it. The title is reflected in the name of +the ``.ipynb`` notebook document file that is saved. + +Menu bar +~~~~~~~~ +The menu bar presents different options that may be used to manipulate the way +the Notebook functions. + +Toolbar +~~~~~~~ +The tool bar gives a quick way of accessing the most-used operations within +the Notebook, by clicking on an icon. + +Creating a new notebook document +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +A new notebook space/document may be created at any time, either from the dashboard, or using the `File | New` menu option from within an active notebook. The new notebook is created within the same working directory and will open in a new browser tab. It will also be reflected as a new entry in the notebook list on the dashboard. + + +Input cells +----------- +Input cells are at the core of the functionality of the IPython Notebook. +They are regions in the document in which you can enter different types of +text and commands. To *execute* or *run* the *current cell*, i.e. the cell +under the cursor, you can use the :kbd:`Shift-Enter` key combination. +This tells the Notebook app to perform the relevant operation for each type of +cell (see below), and then to display the resulting output. + +The notebook consists of a sequence of input cells, labelled ``In[n]``, which +may be executed in a non-linear way, and outputs ``Out[n]``, where ``n`` is a +number which denotes the order in which the cells were executed over the +history of the computational process. The contents of all of these cells are +accessible as Python variables with the same names, forming a complete record +of the history of the computation. + + +Basic workflow +-------------- +The normal workflow in a notebook is, then, quite similar to a standard +IPython session, with the difference that you can edit cells in-place multiple +times until you obtain the desired results, rather than having to +rerun separate scripts with the ``%run`` magic command. (Magic commands do, +however, also work in the notebook; see below). + +Typically, you will work on a computational problem in pieces, organizing +related ideas into cells and moving forward once previous parts work +correctly. This is much more convenient for interactive exploration than +breaking up a computation into scripts that must be executed together, as was +previously necessary, especially if parts of them take a long time to run + +The only significant limitation that the Notebook currently has, compared to +the Qt console, is that it cannot run any code that expects input from the +kernel (such as scripts that call :func:`raw_input`). Very importantly, this +means that the ``%debug`` magic does *not* currently work in the notebook! + +This limitation will be overcome in the future, but in the meantime, there is +a simple solution for debugging: you can attach a Qt console to your existing +notebook kernel, and run ``%debug`` from the Qt console. +If your notebook is running on a local computer (i.e. if you are accessing it +via your localhost address at ``127.0.0.1``), then you can just type +``%qtconsole`` in the notebook and a Qt console will open up, connected to +that same kernel. + +At certain moments, it may be necessary to interrupt a calculation which is +taking too long to complete. This may be done with the ``Kernel | Interrupt`` +menu option, or the :kbd:``Ctrl-i`` keyboard shortcut. +Similarly, it may be necessary or desirable to restart the whole computational +process, with the ``Kernel | Restart`` menu option or :kbd:``Ctrl-.`` shortcut. +This gives an equivalent state to loading the notebook document afresh. - -Text input ----------- - -In addition to code cells and the output they produce (such as figures), you -can also type text not meant for execution. To type text, change the type of a -cell from ``Code`` to ``Markdown`` by using the button or the :kbd:`Ctrl-m m` -keybinding (see below). You can then type any text in Markdown_ syntax, as -well as mathematical expressions if you use ``$...$`` for inline math or -``$$...$$`` for displayed math. - - -Exporting a notebook and importing existing scripts ---------------------------------------------------- - -If you want to provide others with a static HTML or PDF view of your notebook, -use the ``Print`` button. This opens a static view of the document, which you -can print to PDF using your operating system's facilities, or save to a file -with your web browser's 'Save' option (note that typically, this will create -both an html file *and* a directory called `notebook_name_files` next to it -that contains all the necessary style information, so if you intend to share -this, you must send the directory along with the main html file). - -The `Download` button lets you save a notebook file to the Download area -configured by your web browser (particularly useful if you are running the -notebook server on a remote host and need a file locally). The notebook is -saved by default with the ``.ipynb`` extension and the files contain JSON data -that is not meant for human editing or consumption. But you can always export -the input part of a notebook to a plain python script by choosing Python format -in the `Download` drop list. This removes all output and saves the text cells -in comment areas. See ref:`below ` for more details on the -notebook format. - -The notebook can also *import* ``.py`` files as notebooks, by dragging and -dropping the file into the notebook dashboard file list area. By default, the -entire contents of the file will be loaded into a single code cell. But if -prior to import, you manually add the ``# 2`` marker at -the start and then add separators for text/code cells, you can get a cleaner -import with the file broken into individual cells. .. warning:: - While in simple cases you can roundtrip a notebook to Python, edit the - python file and import it back without loss of main content, this is in - general *not guaranteed to work at all*. First, there is extra metadata + While in simple cases you can "roundtrip" a notebook to Python, edit the + Python file, and then import it back without loss of main content, this is + in general *not guaranteed to work*. First, there is extra metadata saved in the notebook that may not be saved to the ``.py`` format. And as the notebook format evolves in complexity, there will be attributes of the notebook that will not survive a roundtrip through the Python form. You @@ -201,61 +241,355 @@ import with the file broken into individual cells. notebook started. But the Python version is *not* an alternate notebook format. + +Keyboard shortcuts +------------------ +All actions in the notebook can be achieved with the mouse, but keyboard +shortcuts are also available for the most common ones, so that productive use +of the notebook can be achieved with minimal mouse usage. The main shortcuts +to remember are the following: + +* :kbd:`Shift-Enter`: + + Execute the current cell, show output (if any), and jump to the next cell + below. If :kbd:`Shift-Enter` is invoked on the last input cell, a new code + cell will also be created. Note that in the notebook, typing :kbd:`Enter` + on its own *never* forces execution, but rather just inserts a new line in + the current input cell. In the Notebook it is thus always necessary to use + :kbd:`Shift-Enter` to execute the cell (or use the ``Cell | Run`` menu + item). + +* :kbd:`Ctrl-Enter`: + Execute the current cell as if it were in "terminal mode", where any + output is shown, but the cursor *remains* in the current cell. This is + convenient for doing quick experiments in place, or for querying things + like filesystem content, without needing to create additional cells that + you may not want to be saved in the notebook. + +* :kbd:`Alt-Enter`: + Executes the current cell, shows the output, and inserts a *new* input + cell between the current cell and the adjacent cell (if one exists). This + is thus a shortcut for the sequence :kbd:`Shift-Enter`, :kbd:`Ctrl-m a`. + (:kbd:`Ctrl-m a` adds a new cell above the current one.) + +* :kbd:`Ctrl-m`: + This is the prefix for *all* other shortcuts, which consist of :kbd:`Ctrl-m` followed by a single letter or character. For example, if you type :kbd:`Ctrl-m h` (that is, the sole letter :kbd:`h` after :kbd:`Ctrl-m`), IPython will show you all the available keyboard shortcuts. -Importing or executing a notebook as a normal Python file ---------------------------------------------------------- -The native format of the notebook, a file with a ``.ipynb`` extension, is a -JSON container of all the input and output of the notebook, and therefore not -valid Python by itself. This means that by default, you can not import a -notebook or execute it as a normal python script. But if you want use -notebooks as regular Python files, you can start the notebook server with:: +Input cell types +---------------- +Each IPython input cell has a *cell type*, of which there is a restricted +number. The type of a cell may be set by using the cell type dropdown on the +toolbar, or via the following keyboard shortcuts: - ipython notebook --script +* **code**: :kbd:`Ctrl-m y` +* **markdown**: :kbd:`Ctrl-m m` +* **raw**: :kbd:`Ctrl-m t` +* **heading**: :kbd:`Ctrl-m 1` - :kbd:`Ctrl-m 6` -or you can set this option permanently in your configuration file with:: +Upon initial creation, each input cell is by default a code cell. - c.NotebookManager.save_script=True -This will instruct the notebook server to save the ``.py`` export of each -notebook adjacent to the ``.ipynb`` at every save. These files can be -``%run``, imported from regular IPython sessions or other notebooks, or -executed at the command-line as normal Python files. Since we export the raw -code you have typed, for these files to be importable from other code you will -have to avoid using syntax such as ``%magics`` and other IPython-specific -extensions to the language. +Code cells +~~~~~~~~~~ +A *code input cell* allows you to edit code inline within the cell, with full +syntax highlighting and autocompletion/introspection. By default, the language +associated to a code cell is Python, but other languages, such as ``julia`` +and ``R``, can be handled using magic commands (see below). -In regular practice, the standard way to differentiate importable code from the -'executable' part of a script is to put at the bottom:: +When a code cell is executed with :kbd:`Shift-Enter`, the code that it +contains is transparently exported and run in that language (with automatic +compiling, etc., if necessary). The result that is returned from this +computation is then displayed in the notebook space as the cell's +*output*. If this output is of a textual nature, it is placed into a +numbered *output cell*. However, many other possible forms of output are also +possible, including ``matplotlib`` figures and HTML tables (as used, for +example, in the ``pandas`` data analyis package). This is known as IPython's +*rich display* capability. - if __name__ == '__main__': - # rest of the code... -Since all cells in the notebook are run as top-level code, you'll need to -similarly protect *all* cells that you do not want executed when other scripts -try to import your notebook. A convenient shortand for this is to define early -on:: +Rich text using Markdown +~~~~~~~~~~~~~~~~~~~~~~~~ +You can document the computational process in a literate way, alternating +descriptive text with code, using *rich text*. In IPython this is accomplished +by marking up text with the Markdown language. The corresponding cells are +called *Markdown input cells*. The Markdown language provides a simple way to +perform this text markup, that is, to specify which parts of the text should +be emphasized (italics), bold, form lists, etc. - script = __name__ == '__main__' -and then on any cell that you need to protect, use:: +When a Markdown input cell is executed, the Markdown code is converted into +the corresponding formatted rich text. This output then *replaces* the +original Markdown input cell, leaving just the visually-significant marked up +rich text. Markdown allows arbitrary HTML code for formatting. - if script: - # rest of the cell... +Within Markdown cells, you can also include *mathematics* in a straightforward +way, using standard LaTeX notation: ``$...$`` for inline mathematics and +``$$...$$`` for displayed mathematics. When the Markdown cell is executed, the LaTeX portions are automatically rendered in the HTML output as equations with high quality typography. This is made possible by MathJax_, which supports a `large subset`_ of LaTeX functionality + +.. _`large subset`: http://docs.mathjax.org/en/latest/tex.html + +Standard mathematics environments defined by LaTeX and AMS-LaTeX (the `amsmath` package) also work, such as +``\begin{equation}...\end{equation}``, and ``\begin{align}...\end{align}``. +New LaTeX macros may be defined using standard methods, +such as ``\newcommand``, by placing them anywhere *between math delimiters* in a Markdown cell. These definitions are then available throughout the rest of the IPython session. (Note, however, that more care must be taken when using the `nbconvert script`_ to output to LaTeX). + +Raw input cells +~~~~~~~~~~~~~~~ +*Raw* input cells provide a place in which you can put additional information +which you do not want to evaluated by the Notebook. This can be used, for +example, to include extra information that is needed when exporting to a +certain format. The output after evaluating a raw cell is just a verbatim copy +of the input. + +Heading cells +~~~~~~~~~~~~~ +You can provide a conceptual structure for your computational document as a +whole using different levels of headings; there are 6 levels available, from +level 1 (top level) down to level 6 (paragraph). These can be used later for +constructing tables of contents, etc. + +As with Markdown cells, a heading input cell is replaced by a rich text +rendering of the heading when the cell is executed. + + +Magic commands +~~~~~~~~~~~~~~ +Magic commands, or *magics*, are commands for controlling IPython itself. +They all begin with ``%`` and are entered into code input cells; the code +cells are executed as usual with :kbd:`Shift-Enter`. + +The magic commands call special functions defined by IPython which manipulate +the computational state in certain ways. + +There are two types of magics: + + - **line magics**: + + These begin with a single ``%`` and take as arguments the rest of the + *same line* of the code cell. Any other lines of the code cell are + treated as if they were part of a standard code cell. + + - **cell magics**: + + These begin with ``%%`` and operate on the *entire* remaining contents of + the code cell. + +Line magics +~~~~~~~~~~~ +Some of the available line magics are the following: + + * ``%load filename``: + + Loads the contents of the file ``filename`` into a new code cell. This + can be a URL for a remote file. + + * ``%timeit code``: + + An easy way to time how long the single line of code ``code`` takes to run + + * ``%config``: + + Configuration of the IPython Notebook + + * ``%lsmagic``: + + Provides a list of all available magic commands + +Cell magics +~~~~~~~~~~~ + + * ``%%latex``: + + Renders the entire contents of the cell in LaTeX, without needing to use + explicit LaTeX delimiters. + + * ``%%bash``: + + The code cell is executed by sending it to be executed by ``bash``. The + output of the ``bash`` commands is captured and displayed in the notebook. + + * ``%%file filename``: + + Writes the contents of the cell to the file ``filename``. + **Caution**: The file is over-written without warning! + + * ``%%R``: + + Execute the contents of the cell using the R language. + + * ``%%timeit``: + + Version of ``%timeit`` which times the entire block of code in the current code cell. + + + +Several of the cell magics provide functionality to manipulate the filesystem +of a remote server to which you otherwise do not have access. + + +Plotting +-------- +One major feature of the Notebook is the ability to interact with +plots that are the output of running code cells. IPython is designed to work +seamlessly with the ``matplotlib`` plotting library to provide this +functionality. + +To set this up, before any plotting is performed you must execute the +``%matplotlib`` magic command. This performs the necessary behind-the-scenes +setup for IPython to work correctly hand in hand with ``matplotlib``; it does +*not*, however, actually execute any Python ``import`` commands, that is, no +names are added to the namespace. + +For more agile *interactive* use of the notebook space, an alternative magic, +``%pylab``, is provided. This does the same work as the ``%matplotlib`` magic, +but *in addition* it automatically executes a standard sequence of ``import`` +statements required to work with the ``%matplotlib`` library, importing the +following names into the namespace: + + ``numpy`` as ``np``; ``matplotlib.pyplot`` as ``plt``; + ``matplotlib``, ``pylab`` and ``mlab`` from ``matplotlib``; and *all names* + from within ``numpy`` and ``pylab``. + +However, the use of ``%pylab`` is discouraged, since names coming from +different packages may collide. In general, the use of ``from package import +*`` is discouraged. A better option is then:: + + %pylab --no-import-all + +which imports the names listed above, but does *not* perform this ``import *`` +imports. + +If the ``%matplotlib`` or ``%pylab` magics are called without an argument, the +output of a plotting command is displayed using the default ``matplotlib`` +backend in a separate window. Alternatively, the backend can be explicitly +requested using, for example:: + + %matplotlib gtk + +A particularly interesting backend is the ``inline`` backend. +This is applicable only for the IPython Notebook and the IPython Qtconsole. +It can be invoked as follows:: -Configuration -------------- + %matplotlib inline -The IPython notebook server can be run with a variety of command line arguments. -To see a list of available options enter: +With this backend, output of plotting commands is displayed *inline* within +the notebook format, directly below the input cell that produced it. The resulting plots will then also be stored in the notebook document. This provides a key part of the functionality for reproducibility_ that the IPython Notebook provides. + +.. _reproducibility: https://en.wikipedia.org/wiki/Reproducibility + +.. _`nbconvert script`: + +Converting notebooks to other formats +------------------------------------- +Newly added in the 1.0 release of IPython is the ``nbconvert`` tool, which +allows you to convert an ``.ipynb`` notebook document file into various static +formats. + +Currently, ``nbconvert`` is provided as a command line tool, run as a script using IPython. In the future, a direct export capability from within the IPython Notebook web app is planned. + +The command-line syntax to run the ``nbconvert`` script is:: + + $ ipython nbconvert --format=FORMAT notebook.ipynb + +This will convert the IPython document file ``notebook.ipynb`` into the output +format given by the ``FORMAT`` string. + +The default output format is HTML, for which the ``--format`` modifier may be omitted:: + + $ ipython nbconvert notebook.ipynb + +The currently supported export formats are the following: + +* HTML: + + - **full_html**: + Standard HTML + + - **simple_html**: + Simplified HTML + + - **reveal**: + HTML slideshow presentation for use with the ``reveal.js`` package + +* PDF: + + - **sphinx_howto**: + The format for Sphinx_ HOWTOs; similar to an ``article`` in LaTeX + + - **sphinx_manual**: + The format for Sphinx_ manuals; similar to a ``book`` in LaTeX + + - **latex**: + An article formatted completely using LaTeX + +* Markup: + + - **rst**: + reStructuredText_ markup + + - **markdown**: + Markdown_ markup + +.. _Sphinx: http://sphinx-doc.org/ +.. _reStructuredText: http://docutils.sourceforge.net/rst.html + +* Python: + + Comments out all the non-Python code to produce a ``.py`` Python + script with just the code content. Currently the output includes IPython magics, and so can be run with ``ipython``, after changing the extension of the script to ``.ipy``. + +The files output by ``nbconvert`` are all placed in a new subdirectory +called ``nbconvert_build``. + +Each of the options for PDF export produces as an intermediate step a LaTeX +``.tex`` file with the same basename as the notebook, as well as individual +files for each figure, and ``.text` files with textual output from running +code cells. + +To actually produce the final PDF file, run the following commands:: + + $ cd nbconvert_build + $ pdflatex notebook + +This requires a local installation of LaTeX on your machine. +The output is a PDF file ``notebook.pdf``, also placed inside the ``nbconvert_build`` subdirectory. + +Alternatively, the output may be sent to standard output with:: + + $ ipython nbconvert mynotebook.ipynb --stdout + +Multiple notebooks can be specified from the command line:: + + $ ipython nbconvert notebook*.ipynb + $ ipython nbconvert notebook1.ipynb notebook2.ipynb + +or via a list in a configuration file, say ``mycfg.py``, containing the text:: + + c = get_config() + c.NbConvertApp.notebooks = ["notebook1.ipynb", "notebook2.ipynb"] + +and using the command:: + + $ ipython nbconvert --config mycfg.py + + +Configuring the IPython Notebook +-------------------------------- +The IPython Notebook can be run with a variety of command line arguments. +To see a list of available options enter:: $ ipython notebook --help Defaults for these options can also be set by creating a file named -ipython_notebook_config.py in your IPython profile folder. The profile folder is -a subfolder of your IPython directory (`ipython locate` will show you where that -is). To create default configuration files (with lots of info on available -options) use: +``ipython_notebook_config.py`` in your IPython *profile folder*. The profile +folder is a subfolder of your IPython directory; to find out where it is +located, run:: + + $ ipython locate + +To create a new set of default configuration files, with lots of information +on available options, use:: $ ipython profile create @@ -264,46 +598,66 @@ options) use: :ref:`config_overview`, in particular :ref:`Profiles`. -Keyboard use ------------- +Extracting standard Python files from notebooks +----------------------------------------------- +``.ipynb`` notebook document files are plain text files which store a +representation in JSON format of the contents of a notebook space. As such, +they are not valid ``.py`` Python scripts, and so can be neither imported +directly with ``import`` in Python, nor run directly as a standard Python +script (though both of these are possible with simple workarounds). -All actions in the notebook can be achieved with the mouse, but we have also -added keyboard shortcuts for the most common ones, so that productive use of -the notebook can be achieved with minimal mouse intervention. The main -key bindings you need to remember are: - -* :kbd:`Shift-Enter`: execute the current cell (similar to the Qt console), - show output (if any) and jump to the next cell below. If :kbd:`Shift-Enter` - was invoked on the last input line, a new code cell will also be created. Note - that in the notebook, simply using :kbd:`Enter` *never* forces execution, - it simply inserts a new line in the current cell. Therefore, in the notebook - you must always use :kbd:`Shift-Enter` to get execution (or use the mouse and - click on the ``Run Selected`` button). - -* :kbd:`Alt-Enter`: this combination is similar to the previous one, with the - exception that, if the next cell below is not empty, a new code cell will be - added to the notebook, even if the cell execution happens not in the last cell. - In this regard, :kbd:`Alt-Enter`: is simply a shortcut for the :kbd:`Shift-Enter`, - :kbd:`Ctrl-m a` sequence. + +To extract the Python code from within a notebook document, the simplest method is to use the ``File | Download as | Python (.py)`` menu item; the resulting ``.py`` script will be downloaded to your browser's default download location. + +An alternative is to pass an argument to the IPython Notebook, from the moment +when it is originally started, specifying that whenever it saves an ``.ipynb`` +notebook document, it should, at the same time, save the corresponding + ``.py`` script. To do so, you can execute the following command:: + + $ ipython notebook --script + +or you can set this option permanently in your configuration file with:: + + c = get_config() + c.NotebookManager.save_script=True + +The result is that standard ``.py`` files are also now generated, which +can be ``%run``, imported from regular IPython sessions or other notebooks, or +executed at the command line, as usual. Since the raw code you have typed is +exported, you must avoid using syntax such as IPython magics and other IPython- +specific extensions to the language for the files to be able to be +successfully imported; or you can change the script's extension to ``.ipy`` and run it with:: + + $ ipython script.ipy + +In normal Python practice, the standard way to differentiate importable code +in a Python script from the "executable" part of a script is to use the +following idiom at the start of the executable part of the code:: + + + if __name__ == '__main__' + + # rest of the code... -* :kbd:`Ctrl-Enter`: execute the current cell in "terminal mode", where any - output is shown but the cursor stays in the current cell, whose input - area is flushed empty. This is convenient to do quick in-place experiments - or query things like filesystem content without creating additional cells you - may not want saved in your notebook. +Since all cells in the notebook are run as top-level code, you will need to +similarly protect *all* cells that you do not want executed when other scripts +try to import your notebook. A convenient shortand for this is to define early +on:: -* :kbd:`Ctrl-m`: this is the prefix for all other keybindings, which consist - of an additional single letter. Type :kbd:`Ctrl-m h` (that is, the sole - letter :kbd:`h` after :kbd:`Ctrl-m`) and IPython will show you the remaining - available keybindings. + script = __name__ == '__main__' + +Then in any cell that you need to protect, use:: + + if script: + # rest of the cell... .. _notebook_security: Security -======== +-------- -You can protect your notebook server with a simple single-password by +You can protect your Notebook server with a simple single password by setting the :attr:`NotebookApp.password` configurable. You can prepare a hashed password using the function :func:`IPython.lib.security.passwd`: @@ -324,51 +678,81 @@ hashed password using the function :func:`IPython.lib.security.passwd`: You can then add this to your :file:`ipython_notebook_config.py`, e.g.:: # Password to use for web authentication - c.NotebookApp.password = u'sha1:67c9e60bb8b6:9ffede0825894254b2e042ea597d771089e11aed' + c = get_config() + c.NotebookApp.password = + u'sha1:67c9e60bb8b6:9ffede0825894254b2e042ea597d771089e11aed' When using a password, it is a good idea to also use SSL, so that your password is not sent unencrypted by your browser. You can start the notebook to -communicate via a secure protocol mode using a self-signed certificate by -typing:: +communicate via a secure protocol mode using a self-signed certificate with +the command:: $ ipython notebook --certfile=mycert.pem .. note:: - A self-signed certificate can be generated with openssl. For example, the - following command will create a certificate valid for 365 days with both - the key and certificate data written to the same file:: + A self-signed certificate can be generated with ``openssl``. For example, + the following command will create a certificate valid for 365 days with + both the key and certificate data written to the same file:: - $ openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout mycert.pem -out mycert.pem + $ openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout mycert. + pem -out mycert.pem Your browser will warn you of a dangerous certificate because it is self-signed. If you want to have a fully compliant certificate that will not -raise warnings, it is possible (but rather involved) to obtain one for free, +raise warnings, it is possible (but rather involved) to obtain one, `as explained in detailed in this tutorial`__. -.. __: http://arstechnica.com/security/news/2009/12/how-to-get-set-with-a-secure-sertificate-for-free.ars +.. __: http://arstechnica.com/security/news/2009/12/how-to-get-set-with-a- +secure-sertificate-for-free.ars -Keep in mind that when you enable SSL support, you'll need to access the +Keep in mind that when you enable SSL support, you will need to access the notebook server over ``https://``, not over plain ``http://``. The startup -message from the server prints this, but it's easy to overlook and think the +message from the server prints this, but it is easy to overlook and think the server is for some reason non-responsive. -Quick how to's -============== + +Connecting to an existing kernel +--------------------------------- + +The notebook server always prints to the terminal the full details of +how to connect to each kernel, with messages such as the following:: + + [IPKernelApp] To connect another client to this kernel, use: + [IPKernelApp] --existing kernel-3bb93edd-6b5a-455c-99c8-3b658f45dde5.json + +This long string is the name of a JSON file that contains all the port and +validation information necessary to connect to the kernel. You can then, for +example, manually start a Qt console connected to the *same* kernel with:: + + $ ipython qtconsole --existing + kernel-3bb93edd-6b5a-455c-99c8-3b658f45dde5.json + +If you have only a single kernel running, simply typing:: + + $ ipython qtconsole --existing + +will automatically find it. (It will always find the most recently +started kernel if there is more than one.) You can also request this +connection data by typing ``%connect_info``; this will print the same +file information as well as the content of the JSON data structure it contains. + Running a public notebook server -------------------------------- -If you want to access your notebook server remotely with just a web browser, -here is a quick set of instructions. Start by creating a certificate file and -a hashed password as explained above. Then, create a custom profile for the -notebook. At the command line, type:: +If you want to access your notebook server remotely via a web browser, +you can do the following. - ipython profile create nbserver +Start by creating a certificate file and a hashed password, as explained +above. Then create a custom profile for the notebook, with the following +command line, type:: -In the profile directory, edit the file ``ipython_notebook_config.py``. By -default the file has all fields commented, the minimum set you need to -uncomment and edit is here:: + $ ipython profile create nbserver + +In the profile directory just created, edit the file +``ipython_notebook_config.py``. By default, the file has all fields +commented; the minimum set you need to uncomment and edit is the following:: c = get_config() @@ -379,8 +763,8 @@ uncomment and edit is here:: c.NotebookApp.certfile = u'/absolute/path/to/your/certificate/mycert.pem' c.NotebookApp.ip = '*' c.NotebookApp.open_browser = False - c.NotebookApp.password = u'sha1:bcd259ccf...your hashed password here' - # It's a good idea to put it on a known, fixed port + c.NotebookApp.password = u'sha1:bcd259ccf...[your hashed password here]' + # It is a good idea to put it on a known, fixed port c.NotebookApp.port = 9999 You can then start the notebook and access it later by pointing your browser to @@ -389,12 +773,12 @@ You can then start the notebook and access it later by pointing your browser to Running with a different URL prefix ----------------------------------- -The notebook dashboard (i.e. the default landing page with an overview -of all your notebooks) typically lives at a URL path of -"http://localhost:8888/". If you want to have it, and the rest of the -notebook, live under a sub-directory, -e.g. "http://localhost:8888/ipython/", you can do so with -configuration options like these (see above for instructions about +The notebook dashboard (the landing page with an overview +of the notebooks in your working directory) typically lives at the URL +``http://localhost:8888/``. If you prefer that it lives, together with the +rest of the notebook, under a sub-directory, +e.g. ``http://localhost:8888/ipython/``, you can do so with +configuration options like the following (see above for instructions about modifying ``ipython_notebook_config.py``):: c.NotebookApp.base_project_url = '/ipython/' @@ -404,77 +788,128 @@ modifying ``ipython_notebook_config.py``):: Using a different notebook store -------------------------------- -By default the notebook server stores notebooks as files in the working -directory of the notebook server, also known as the ``notebook_dir``. This -logic is implemented in the :class:`FileNotebookManager` class. However, the -server can be configured to use a different notebook manager class, which can -store the notebooks in a different format. Currently, we ship a -:class:`AzureNotebookManager` class that stores notebooks in Azure blob -storage. This can be used by adding the following lines to your +By default, the Notebook app stores the notebook documents that it saves as +files in the working directory of the Notebook app, also known as the +``notebook_dir``. This logic is implemented in the +:class:`FileNotebookManager` class. However, the server can be configured to +use a different notebook manager class, which can +store the notebooks in a different format. + +Currently, we ship a :class:`AzureNotebookManager` class that stores notebooks +in Azure blob storage. This can be used by adding the following lines to your ``ipython_notebook_config.py`` file:: - c.NotebookApp.notebook_manager_class = 'IPython.html.services.notebooks.azurenbmanager.AzureNotebookManager' + c.NotebookApp.notebook_manager_class = + 'IPython.html.services.notebooks.azurenbmanager.AzureNotebookManager' c.AzureNotebookManager.account_name = u'paste_your_account_name_here' c.AzureNotebookManager.account_key = u'paste_your_account_key_here' c.AzureNotebookManager.container = u'notebooks' -In addition to providing your Azure Blob Storage account name and key, you will -have to provide a container name; you can use multiple containers to organize -your Notebooks. +In addition to providing your Azure Blob Storage account name and key, you +will have to provide a container name; you can use multiple containers to +organize your notebooks. .. _notebook_format: -The notebook format -=================== - -The notebooks themselves are JSON files with an ``ipynb`` extension, formatted +Notebook JSON file format +------------------------- +Notebook documents are JSON files with an ``.ipynb`` extension, formatted as legibly as possible with minimal extra indentation and cell content broken across lines to make them reasonably friendly to use in version-control -workflows. You should be very careful if you ever edit manually this JSON +workflows. You should be very careful if you ever manually edit this JSON data, as it is extremely easy to corrupt its internal structure and make the file impossible to load. In general, you should consider the notebook as a -file meant only to be edited by IPython itself, not for hand-editing. +file meant only to be edited by the IPython Notebook app itself, not for +hand-editing. .. note:: - Binary data such as figures are directly saved in the JSON file. This - provides convenient single-file portability but means the files can be - large and diffs of binary data aren't very meaningful. Since the binary - blobs are encoded in a single line they only affect one line of the diff - output, but they are typically very long lines. You can use the - 'ClearAll' button to remove all output from a notebook prior to - committing it to version control, if this is a concern. - -The notebook server can also generate a pure-python version of your notebook, -by clicking on the 'Download' button and selecting ``py`` as the format. This -file will contain all the code cells from your notebook verbatim, and all text -cells prepended with a comment marker. The separation between code and text + Binary data such as figures are also saved directly in the JSON file. + This provides convenient single-file portability, but means that the + files can be large; a ``diff`` of binary data is also not very + meaningful. Since the binary blobs are encoded in a single line, they + affect only one line of the ``diff`` output, but they are typically very + long lines. You can use the ``Cell | All Output | Clear`` menu option to + remove all output from a notebook prior to committing it to version + control, if this is a concern. + +The notebook server can also generate a pure Python version of your notebook, +using the ``File | Download as`` menu option. The resulting ``.py`` file will +contain all the code cells from your notebook verbatim, and all Markdown cells +prepended with a comment marker. The separation between code and Markdown cells is indicated with special comments and there is a header indicating the -format version. All output is stripped out when exporting to python. - -Here is an example of a simple notebook with one text cell and one code input -cell, when exported to python format:: - - # 2 - - # - - # A text cell - - # - - print "hello IPython" +format version. All output is removed when exporting to Python. + +As an example, consider a simple notebook called ``simple.ipynb`` which +contains one Markdown cell, with the content ``The simplest notebook.``, one +code input cell with the content ``print "Hello, IPython!"``, and the +corresponding output. + +The contents of the notebook document ``simple.ipynb`` is the following JSON +container:: + + { + "metadata": { + "name": "simple" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": "The simplest notebook." + }, + { + "cell_type": "code", + "collapsed": false, + "input": "print \"Hello, IPython\"", + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": "Hello, IPython\n" + } + ], + "prompt_number": 1 + } + ], + "metadata": {} + } + ] + } + + +The corresponding Python script is:: + + # -*- coding: utf-8 -*- + # 3.0 + + # + + # The simplest notebook. + + # + + print "Hello, IPython" + +Note that indeed the output of the code cell, which is present in the JSON +container, has been removed in the ``.py`` script. Known issues -============ +------------ When behind a proxy, especially if your system or browser is set to autodetect -the proxy, the html notebook might fail to connect to the server's websockets, +the proxy, the Notebook app might fail to connect to the server's websockets, and present you with a warning at startup. In this case, you need to configure your system not to use the proxy for the server's address. -In Firefox, for example, go to the Preferences panel, Advanced section, +For example, in Firefox, go to the Preferences panel, Advanced section, Network tab, click 'Settings...', and add the address of the notebook server to the 'No proxy for' field.