add package_versions() and option to print info in test.py

package_versions() is a new function that returns a namedtuple of
version information of the dependent packages.  It should also be useful
to see if Travis is running the correct package versions.  I made this
with Issue #235 in mind.  A --verbose option was added to test.py to
display this version information.  Additionally, this new function could
serve a use in debugging future issues.

Author: Micah Cochran

.requirements-2.6.txt

@@ -1 +1,2 @@
+argparse
 unittest2

lib/mpl_toolkits/basemap/diagnostic.py

@@ -0,0 +1,56 @@
+"""
+These are diagnostic and debugging functions for basemap.
+"""
+
+def package_versions():
+    """
+    Gives version information for dependent packages.
+
+    returns namedtuple BasemapPackageVersions
+    """
+    from collections import namedtuple
+    from sys import version as sys_version
+
+    from matplotlib import __version__ as matplotlib_version
+    from numpy import __version__ as numpy_version
+    import pyproj
+    from shapefile import __version__ as pyshp_version
+
+    import _geoslib
+    from mpl_toolkits.basemap import __version__ as basemap_version
+    
+    # import optional dependencies
+    try:
+        from OWSLib import __version__ as OWSLib_version
+    except ImportError:
+        OWSLib_version = 'not installed'
+
+    try:
+        from PIL import VERSION as pil_version
+        try:
+            from PIL import PILLOW_VERSION as pillow_version
+        except ImportError:
+            pillow_verison = 'not installed'
+    except ImportError:
+        pil_version = 'not installed'
+        pillow_verison = 'not installed'
+
+    BasemapPackageVersions = namedtuple(
+                               'BasemapPackageVersions',
+                               """Python, basemap, matplotlib,
+                                  numpy, pyproj, pyshp, PROJ4, GEOS,
+                                  OWSLib, PIL, Pillow""")
+
+    return BasemapPackageVersions(
+                   Python = sys_version,
+                   basemap = basemap_version,
+                   matplotlib = matplotlib_version,
+                   numpy = numpy_version,
+                   pyproj = pyproj.__version__,
+                   pyshp = pyshp_version,
+                   PROJ4 = pyproj.Proj(init='epsg:4326').proj_version,
+                   GEOS = _geoslib.__geos_version__,
+                   # optional dependencies below
+                   OWSLib = OWSLib_version,
+                   PIL = pil_version,
+                   Pillow = pillow_version)

lib/mpl_toolkits/basemap/test.py

@@ -206,5 +206,25 @@ def test():
 
 
 if __name__ == '__main__':
+    # When called with the -v / --verbose commandline parameter, it will
+    # give package dependent version information:
+    #   $ python test.py --verbose
+
+    import argparse # standard module in Python >= 2.7 and >= 3.2
     import unittest
+
+    from mpl_toolkits.basemap.diagnostic import package_versions
+    
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-v', '--verbose',action='count')
+    args = parser.parse_args()
+    
+    # VERBOSITY will default to None if not a parameter
+    VERBOSITY = vars(args)['verbose']
+    if VERBOSITY != None:
+        pkg_vers = package_versions()
+        print('Basemaps installed package versions:')
+        print('{}\n'.format(pkg_vers))
+
     unittest.main()
+