tests failures because of missing_module_test

General Information:

• OS: Ubuntu 20.04
• Python version: 3.10.4
• Library version: 0.8.4

Describe the bug: When I execute python3 -m unittest dataprofiler/tests/reports/test_graphs.py

test_no_matplotlib seems to break something internal within matplotlib.

After it runs, multiple other tests in test_graphs.py fail with the error:

======================================================================
ERROR: test_null_list (dataprofiler.tests.reports.test_graphs.TestPlotMissingValuesMatrix)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/codespace/.python/current/lib/python3.10/unittest/mock.py", line 1369, in patched
    return func(*newargs, **newkeywargs)
  File "/workspaces/DataProfiler/dataprofiler/tests/reports/test_graphs.py", line 222, in test_null_list
    fig = graphs.plot_missing_values_matrix(profiler)
  File "/workspaces/DataProfiler/dataprofiler/reports/utils.py", line 50, in new_f
    return f(*args, **kwds)
  File "/workspaces/DataProfiler/dataprofiler/reports/graphs.py", line 208, in plot_missing_values_matrix
    return plot_col_missing_values(profiler.profile, ax=ax, title=title)
  File "/workspaces/DataProfiler/dataprofiler/reports/utils.py", line 50, in new_f
    return f(*args, **kwds)
  File "/workspaces/DataProfiler/dataprofiler/reports/graphs.py", line 259, in plot_col_missing_values
    fig = plt.figure()
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/_api/deprecation.py", line 454, in wrapper
    return func(*args, **kwargs)
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 771, in figure
    manager = new_figure_manager(
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 346, in new_figure_manager
    _warn_if_gui_out_of_main_thread()
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 336, in _warn_if_gui_out_of_main_thread
    if (_get_required_interactive_framework(_get_backend_mod()) and
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 206, in _get_backend_mod
    switch_backend(dict.__getitem__(rcParams, "backend"))
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 251, in switch_backend
    switch_backend(candidate)
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/pyplot.py", line 288, in switch_backend
    class backend_mod(matplotlib.backend_bases._Backend):
  File "/workspaces/DataProfiler/venv/lib/python3.10/site-packages/matplotlib/_api/__init__.py", line 224, in __getattr__
    raise AttributeError(
AttributeError: module 'matplotlib' has no attribute 'backend_bases'

When the tests are run individually they work fine:

/workspaces/DataProfiler ❯❯❯ python3 -m unittest dataprofiler.tests.reports.test_graphs.TestPlotMissingValuesMatrix.test_null_list

.
----------------------------------------------------------------------
Ran 1 test in 0.069s

OK

If I comment out test_no_matplotlib then all of the tests pass when running python3 -m unittest dataprofiler/tests/reports/test_graphs.py

[JGSweets]

#736 is a rework that should prevent this error in the future as now we don’t modify the modules themselves.

[JGSweets]

In regards to testing, I think we should mimic the CI as well. We should also update the ghpages to show the same where different. However, we shouldn’t restrict as both should function in the current design.