FIX: Weak dep on mpl (mne-tools#5250)

README.rst

@@ -73,10 +73,11 @@ The minimum required dependencies to run MNE-Python are:
 - Python >= 2.7
 - NumPy >= 1.8
 - SciPy >= 0.12
-- Matplotlib >= 1.3
 
 For full functionality, some functions require:
 
+- Matplotlib >= 1.3
+- Mayavi >= 4.6
 - Scikit-learn >= 0.15 (>= 0.18 recommended)
 - NiBabel >= 2.1.0
 - Pandas >= 0.13

mne/tests/test_import_nesting.py

@@ -1,7 +1,7 @@
 import sys
 from subprocess import Popen, PIPE
 
-from mne.utils import run_tests_if_main, requires_version
+from mne.utils import run_tests_if_main
 
 
 run_script = """
@@ -22,35 +22,37 @@
                        and sys.modules[x] is not None)
 bad = scipy_submodules - ok_scipy_submodules
 if len(bad) > 0:
-    out.append('Found un-nested scipy submodules: %s' % list(bad))
+    out.append('scipy submodules: %s' % list(bad))
 
 # check sklearn and others
-_sklearn = _pandas = _nose = _mayavi = False
+_sklearn = _pandas = _nose = _mayavi = _matplotlib = False
 for x in sys.modules.keys():
     if x.startswith('sklearn') and not _sklearn:
-        out.append('Found un-nested sklearn import')
+        out.append('sklearn')
         _sklearn = True
     if x.startswith('pandas') and not _pandas:
-        out.append('Found un-nested pandas import')
+        out.append('pandas')
         _pandas = True
     if x.startswith('nose') and not _nose:
-        out.append('Found un-nested nose import')
+        out.append('nose')
         _nose = True
     if x.startswith('mayavi') and not _mayavi:
-        out.append('Found un-nested mayavi import')
+        out.append('mayavi')
         _mayavi = True
+    if x.startswith('matplotlib') and not _matplotlib:
+        out.append('matplotlib')
+        _matplotlib = True
 if len(out) > 0:
-    print('\\n' + '\\n'.join(out), end='')
+    print('\\nFound un-nested imports for:\\n' + '\\n'.join(out), end='')
     exit(1)
 """
 
 
-@requires_version('scipy', '0.11')  # old ones not organized properly
 def test_module_nesting():
-    """Test that module imports are necessary
-    """
+    """Test that module imports are properly nested."""
     proc = Popen([sys.executable, '-c', run_script], stdout=PIPE, stderr=PIPE)
     stdout, stderr = proc.communicate()
+    stdout = stdout.decode('utf-8')
     if proc.returncode:
         raise AssertionError(stdout)
 

mne/viz/topo.py

@@ -8,10 +8,10 @@
 #
 # License: Simplified BSD
 
+from copy import deepcopy
 from functools import partial
 from itertools import cycle
-from copy import deepcopy
-from matplotlib.colors import colorConverter
+
 import numpy as np
 
 from ..io.constants import Bunch
@@ -341,6 +341,7 @@ def _plot_timeseries(ax, ch_idx, tmin, tmax, vmin, vmax, ylim, data, color,
                      labels=None):
     """Show time series on topo split across multiple axes."""
     import matplotlib.pyplot as plt
+    from matplotlib.colors import colorConverter
     picker_flag = False
     for data_, color_ in zip(data, color):
         if not picker_flag: