BLD: make util/print_versions.py standlone as well

Author: y-p

pandas/util/print_versions.py

@@ -120,6 +120,21 @@ def show_versions(as_json=False):
         for k, stat in deps_blob:
             print("%s: %s" % (k, stat))
 
+def main():
+        # optparse is 2.6-safe
+    from optparse import OptionParser
+    parser = OptionParser()
+    parser.add_option("-j", "--json", metavar="FILE", nargs=1,
+                      help="Save output as JSON into file, pass in '-' to output to stdout")
+
+    (options, args) = parser.parse_args()
+
+    if options.json == "-":
+        options.json = True
+
+    show_versions(as_json=options.json)
+
+    return 0
 
 if __name__ == "__main__":
-    show_versions(as_json=False)
+    sys.exit(main())