Add ability to filter post data parameters

vcr/filters.py

@@ -1,4 +1,6 @@
+from six import BytesIO
 from six.moves.urllib.parse import urlparse, urlencode, urlunparse
+from collections import OrderedDict
 import copy
 
 
@@ -22,3 +24,17 @@ def remove_query_parameters(request, query_parameters_to_remove):
         uri_parts[4] = urlencode(new_query)
         request.uri = urlunparse(uri_parts)
     return request
+
+
+def remove_post_data_parameters(request, post_data_parameters_to_remove):
+    if request.method == 'POST' and not isinstance(request.body, BytesIO):
+        post_data = OrderedDict()
+        for k, sep, v in [p.partition(b'=') for p in request.body.split(b'&')]:
+            if k in post_data:
+                post_data[k].append(v)
+            elif len(k) > 0 and k.decode('utf-8') not in post_data_parameters_to_remove:
+                post_data[k] = [v]
+        request.body = b'&'.join(
+            b'='.join([k, v])
+            for k, vals in post_data.items() for v in vals)
+    return request