pypath-magic

pypath-magic provides a simple interface for adding modules and packages to your Python path. This page should provide a good overview, but you might also want to check out the original pypath-magic article and the article introducing the command-line interface

Unlike modifications to sys.path, this allows you to easily modify your path across sessions. Unlike modifications to environment variables, this doesn't require you to explain to users, students, and colleagues how to modify environment variables.

Command-line interface

In addition to the namesake IPython magic interface, version 0.3 adds a command-line interface (CLI) that resembles the IPython interface. After installing the latest version (pip install pypath_magic), you'll have access to a pypath command in your favorite terminal/shell.

An example IPython workflow with pypath-magic is described below. The CLI has a similar interface:

pypath <command> [PATH]

The standard commands are:

pypath add [PATH]       Add path to user's Python path.
pypath delete [PATH]    Delete path from user's Python path.
pypath [list]           List all paths defined by user.
pypath list-all         List all paths in user's Python path.
pypath path-file        Print path to user's path file.

Continue below to this in action for the IPython interface.

IPython magic

pypath-magic adds an IPython magic (err... Jupyter magic?) command for easily manipulating your Python path. To use the magic command, just load the extension from an IPython session:

In [1]: %load_ext pypath_magic

After loading, you will have access to the %pypath magic. You can type:

In [2]: %pypath

to list all the custom paths added by pypath-magic. When you get started, you won't have anything there. To add some custom paths, just change to a directory and call %pypath -a:

In [3]: %cd path/to/my-repo

In [4]: ls
data_wranglers.py
plot_helpers.py

In [5]: %pypath -a
Added u'/absolute/path/to/my-repo' to path.

In [6]: %pypath
/absolute/path/to/my-repo

Now you can reuse those helper functions:

In [7]: from plot_helpers import plot_slope_marker

Changes to your python path will persist across IPython sessions, and those paths will be available outside of IPython. If you later want to delete a directory from your path, just use %pypath -d:

In [8]: %cd path/to/my-repo

In [9]: %pypath -d
Deleted u'/absolute/path/to/my-repo' from path.

You can also list your entire python path with %pypath -l:

In [10]: %pypath -l

/Users/tonysyu/code/yutils
/Users/tonysyu/code/skimage
/Users/tonysyu/code/mpl/lib
/Users/tonysyu/code/ipython
/Users/tonysyu/code/deli
/Users/tonysyu/code/mpltools
/Applications/Canopy.app/appdata/canopy-1.4.1.1975.macosx-x86_64/Canopy.app/Contents/lib/python27.zip
/Applications/Canopy.app/appdata/canopy-1.4.1.1975.macosx-x86_64/Canopy.app/Contents/lib/python2.7
...
/absolute/path/to/my-repo

For additional usage information, type:

In [11]: %pypath?

Install

To install using pip:

$ pip install pypath_magic

To install from source:

$ git clone https://github.com/tonysyu/pypath-magic.git
$ cd pypath-magic
$ python setup.py install

If you get an error like:

error: invalid command 'egg_info'

you probably need to update setuptools:

pip install --upgrade setuptools

Dependencies

• Python 2.7/3.4 (older versions probably work, but this is not tested)
• IPython >= 1.1
• setuptools >= 0.7

License

New BSD (a.k.a. Modified BSD). See LICENSE file in this directory for details.