added transformation to bytes

diff --git a/tweepy/api.py b/tweepy/api.py
index 38b7a2e0a8dafceeb87268abe3fffc7c0eb5a73e..a424a394e6f53a25b918161a09c45f3fa188bf88 100644 (file)
--- a/tweepy/api.py
+++ b/tweepy/api.py
@@ -220,8 +220,9 @@ class API(object):
             :allowed_param:
         """
         f = kwargs.pop('file', None)
+        h = f.read(32)
 
-        file_type = imghdr.what(filename, f) or mimetypes.guess_type(filename)[0]
+        file_type = imghdr.what(filename, h=h) or mimetypes.guess_type(filename)[0]
         if file_type == 'gif':
             max_size = 14649
         else: