MAINT: Require networkx<2.3 for Python 2

Author: effigies

Diff for: nipype/info.py

@@ -101,6 +101,7 @@ def get_nipype_gitversion():
 # versions
 NIBABEL_MIN_VERSION = '2.1.0'
 NETWORKX_MIN_VERSION = '1.9'
+NETWORKX_MAX_VERSION_27 = '2.2'
 NUMPY_MIN_VERSION = '1.9.0'
 # Numpy bug in python 3.7:
 # https://www.opensourceanswers.com/blog/you-shouldnt-use-python-37-for-data-science-right-now.html
@@ -135,7 +136,8 @@ def get_nipype_gitversion():
 PROVIDES = ['nipype']
 REQUIRES = [
     'nibabel>=%s' % NIBABEL_MIN_VERSION,
-    'networkx>=%s' % NETWORKX_MIN_VERSION,
+    'networkx>=%s,<=%s ; python_version < "3.0"' % (NETWORKX_MIN_VERSION, NETWORKX_MAX_VERSION_27),
+    'networkx>=%s ; python_version >= "3.0"' % NETWORKX_MIN_VERSION,
     'numpy>=%s,!=%s ; python_version == "2.7"' % (NUMPY_MIN_VERSION, NUMPY_BAD_VERSION_27),
     'numpy>=%s ; python_version > "3.0" and python_version < "3.7"' % NUMPY_MIN_VERSION,
     'numpy>=%s ; python_version >= "3.7"' % NUMPY_MIN_VERSION_37,