Error

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/usr/local/lib/python2.7/dist-packages/flask_restful/__init__.py", line 242, in wrapper
    resp = resource(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/flask/views.py", line 84, in view
    return self.dispatch_request(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/flask_restful/__init__.py", line 318, in dispatch_request
    resp = meth(*args, **kwargs)
  File "test.py", line 162, in post
    key.set_contents_from_filename(file.readlines())
  File "/usr/local/lib/python2.7/dist-packages/boto/s3/key.py", line 1287, in set_contents_from_filename
    with open(filename, 'rb') as fp:
TypeError: coercing to Unicode: need string or buffer, list found