Automagically import missing modules in IPython: instead of :

In [1]: plt.plot([1, 2], [3, 4])
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-1-994ba2bf13c0> in <module>()
----> 1 plt.plot([1, 2], [3, 4])

NameError: name 'plt' is not defined

In [2]: from matplotlib import pyplot as plt

In [3]: plt.plot([1, 2], [3, 4])
Out[3]: [<matplotlib.lines.Line2D at 0x7f73f0179198>]

do what I mean:

In [1]: plt.plot([1, 2], [3, 4])
Autoimport: from matplotlib import pyplot as plt
Out[1]: [<matplotlib.lines.Line2D at 0x7f7e253552b0>]

Inspired from @OrangeFlash81's version, with many improvements:

• Does not rely on re-execution, but instead hooks the user namespace; thus, safe even in the presence of side effects, and works for tab completion and magics too.
• Learns your preferred aliases from the history -- plt is not hardcoded to alias matplotlib.pyplot, just found because you previously imported pyplot under this alias.
• Suppresses irrelevant chained tracebacks.
• Auto-imports submodules.
• pip-installable.

To see auto imports from the current session: %autoimport -l

To clear the cache for a symbol with multiple possible imports: %autoimport -c SYMBOL

As usual, install using pip:

$ pip install ipython-autoimport  # from PyPI
$ pip install git+https://github.com/anntzer/ipython-autoimport  # from Github

Then, append the output of python -m ipython_autoimport to the ipython_config.py file in the directory printed by ipython profile locate (typically ~/.ipython/profile_default/). If you don't have such a file at all, first create it with ipython profile create.

When using Spyder, the above registration method will not work; instead, add %load_ext ipython_autoimport to the Preferences --> IPython console --> Startup --> Run code option.

Note that upon loading, ipython_autoimport will register its submodule auto-importer to IPython's "limited evalutation" completer policy (on IPython versions that support it).

Run tests with pytest.

Constructs such as :

class C:
   auto_imported_value

will not work, because they are run using the class locals (rather than the patched locals); patching globals would not work because LOAD_NAME queries globals using PyDict_GetItem exactly (note that it queries locals using PyObject_GetItem; also, LOAD_GLOBALS queries both globals and builtins using PyObject_GetItem so we could possibly get away with patching the builtins dict instead, but that seems a bit too invasive...).

When using Jedi autocompletion (the default if Jedi is installed as of IPython 7.2), trying to tab-complete not-yet-imported global names to trigger an import failure, because Jedi purposefully converts the global dict to a namespace object and looks up attributes using getattr_static. Jedi can be disabled by adding c.Completer.use_jedi = False to the ipython_config.py file.