Add compare_namespaces.py helper

Summary: Pull Request resolved: https://github.com/fairinternal/fairseq-py/pull/597

Differential Revision: D15432965

Pulled By: myleott

fbshipit-source-id: 4471a2a8bb468bb639a80f977ab4c20480acb461

scripts/compare_namespaces.py

+#!/usr/bin/env python
+"""Helper script to compare two argparse.Namespace objects."""
+
+from argparse import Namespace
+
+
+def main():
+
+    ns1 = eval(input('Namespace 1: '))
+    ns2 = eval(input('Namespace 2: '))
+
+    def keys(ns):
+        ks = set()
+        for k in dir(ns):
+            if not k.startswith('_'):
+                ks.add(k)
+        return ks
+
+    k1 = keys(ns1)
+    k2 = keys(ns2)
+
+    def print_keys(ks, ns1, ns2=None):
+        for k in ks:
+            if ns2 is None:
+                print('{}\t{}'.format(k, getattr(ns1, k, None)))
+            else:
+                print('{}\t{}\t{}'.format(k, getattr(ns1, k, None), getattr(ns2, k, None)))
+
+    print('Keys unique to namespace 1:')
+    print_keys(k1 - k2, ns1)
+    print()
+
+    print('Keys unique to namespace 2:')
+    print_keys(k2 - k1, ns2)
+    print()
+
+    print('Overlapping keys with different values:')
+    ks = [k for k in k1 & k2 if getattr(ns1, k, 'None') != getattr(ns2, k, 'None')]
+    print_keys(ks, ns1, ns2)
+    print()
+
+
+if __name__ == '__main__':
+    main()