From 8ba44f2099f8971cd8885c8bc3786ca2455157f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20=C5=81uszczyk?= <m0@qed.ai>
Date: Fri, 21 Oct 2016 21:35:39 +0200
Subject: [PATCH] Fix PdfFileMerger for file objects on Python 3.

The previous check was always evaluated to False on Python 3, so I replaced it
with a duck-typing one compatible with both Python versions.
---
 PyPDF2/merger.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PyPDF2/merger.py b/PyPDF2/merger.py
index 27702ad..c3373e4 100644
--- a/PyPDF2/merger.py
+++ b/PyPDF2/merger.py
@@ -113,7 +113,7 @@ class PdfFileMerger(object):
         if isString(fileobj):
             fileobj = file(fileobj, 'rb')
             my_file = True
-        elif isinstance(fileobj, file):
+        elif hasattr(fileobj, "seek") and hasattr(fileobj, "read"):
             fileobj.seek(0)
             filecontent = fileobj.read()
             fileobj = StreamIO(filecontent)