Merge pull request #6 from yahoo/plot-optional

make plotting dependencies optional

graphkit/network.py

@@ -3,10 +3,7 @@
 
 import time
 import os
-import pydot
 import networkx as nx
-import matplotlib.pyplot as plt
-import matplotlib.image as mpimg
 
 from io import StringIO
 
@@ -297,6 +294,9 @@ def plot(self, filename=None, show=False):
             An instance of the pydot graph
 
         """
+        import pydot
+        import matplotlib.pyplot as plt
+        import matplotlib.image as mpimg
 
         assert self.graph is not None
 

setup.py

@@ -28,7 +28,10 @@
      author_email='huyng@yahoo-inc.com',
      url='http://github.com/yahoo/graphkit',
      packages=['graphkit'],
-     install_requires=['networkx', 'pydot', 'matplotlib'],
+     install_requires=['networkx'],
+     extras_require={
+          'plot': ['pydot', 'matplotlib']
+     },
      tests_require=['numpy'],
      license='Apache-2.0',
      keywords=['graph', 'computation graph', 'DAG', 'directed acyclical graph'],