Missing __init__.py file in mpl_toolkits

[frenzymadness]

Bug report

Bug summary

I am building python-matplotlib RPM for Fedora and I've found out that I cannot execute tests because the file mpl_toolkits/__init__.py is missing.

Code for reproduction

MATPLOTLIBDATA=$PWD/lib/matplotlib/mpl-data/ PYTHONPATH=/builddir/build/BUILDROOT/python-matplotlib-2.1.0-1.fc28.2.x86_64/usr/lib64/python2.7/site-packages/ python tests.py 

Actual outcome

('Python byte-compilation optimization level:', 0)
========================================== test session starts ==========================================
platform linux2 -- Python 2.7.14, pytest-3.2.3, py-1.5.2, pluggy-0.4.0
rootdir: /builddir/build/BUILD/matplotlib-2.1.0, inifile: pytest.ini

===================================== no tests ran in 0.00 seconds ======================================
ERROR: file or package not found: mpl_toolkits.tests (missing __init__.py?)

$ cat setup.cfg
[packages]
tests = True
toolkits_tests = True

[rc_options]
backend = TkAgg
$ cd /builddir/build/BUILDROOT/python-matplotlib-2.1.0-1.fc28.2.x86_64/usr/lib64/python2.7/site-packages/mpl_toolkits/
$ ll
total 92
drwxr-xr-x. 2 mockbuild mock  4096 Nov 21 11:44 axes_grid
drwxr-xr-x. 2 mockbuild mock  4096 Nov 21 11:44 axes_grid1
drwxr-xr-x. 2 mockbuild mock  4096 Nov 21 11:44 axisartist
-rw-r--r--. 1 mockbuild mock  3966 Oct  3 08:50 exceltools.py
-rw-r--r--. 2 mockbuild mock  3966 Nov 21 11:44 exceltools.pyc
-rw-r--r--. 2 mockbuild mock  3966 Nov 21 11:44 exceltools.pyo
-rw-r--r--. 1 mockbuild mock 19211 Oct  3 08:50 gtktools.py
-rw-r--r--. 1 mockbuild mock 19805 Nov 21 11:44 gtktools.pyc
-rw-r--r--. 1 mockbuild mock 19766 Nov 21 11:44 gtktools.pyo
drwxr-xr-x. 2 mockbuild mock  4096 Nov 21 11:44 mplot3d
drwxr-xr-x. 3 mockbuild mock  4096 Nov 21 11:44 tests

Expected outcome

Existing __init__.py file in /usr/lib64/python2.7/site-packages/mpl_toolkits/ and running tests.

Matplotlib version

• Operating system: Fedora 28 (rawhide)
• Matplotlib version: 2.1.0 built from source
• Matplotlib backend (print(matplotlib.get_backend())): TkAgg
• Python version: 2.7.14 from distribution package

[jklymak]

Its in master, so there is something wrong w/ your install. Closing, but feel free to reopen if you think this is a Matplotlib problem.

[chbrown]

I hit upon this issue regarding the missing __init__.py when I updated my matplotlib to 2.2.2 via pip install -U matplotlib, with Python 3.6.4 (from Homebrew), which caused csvkit, at least, to spout the following warning (repeated a total of 78 times, in quick succession):

/usr/local/Cellar/python/3.6.4_4/Frameworks/Python.framework/Versions/3.6/lib/python3.6/importlib/_bootstrap_external.py:426: ImportWarning: Not importing directory /usr/local/lib/python3.6/site-packages/mpl_toolkits: missing __init__

Neither the wheel (pip uninstall -y matplotlib && pip install matplotlib) nor source (pip uninstall -y matplotlib && pip install --no-binary matplotlib matplotlib) properly installed that __init__.py file, but I can silence the warnings, and presumably do what pip ought to be doing, by manually installing the missing file:

wget https://pypi.python.org/packages/ec/ed/46b835da53b7ed05bd4c6cae293f13ec26e877d2e490a53a709915a9dcb7/matplotlib-2.2.2.tar.gz
tar -x -O - -f matplotlib-2.2.2.tar.gz matplotlib-2.2.2/lib/mpl_toolkits/__init__.py > /usr/local/lib/python3.6/site-packages/mpl_toolkits/__init__.py

Why pip seems to neglect that file, which is right there in the tarball, I don't know.

[jklymak]

Maybe the toolkits aren't being installed by default in the pip build? Re-opening to attract attention from someone who knows more about the builds and pip....

[anntzer]

If we keep the mpl_toolkits namespace around (really not clear it's worth it, but heh), we should probably just make it an implicit namespace package (per https://packaging.python.org/guides/packaging-namespace-packages/#native-namespace-packages) in 3.0.

[QuLogic]

Closing as duplicate of #25244, as that's where discussion is happening.