requests/models.py
<<<<<<< SEARCH
    def prepare_content_length(self, body):
        self.headers['Content-Length'] = '0'
        if hasattr(body, 'seek') and hasattr(body, 'tell'):
            body.seek(0, 2)
            self.headers['Content-Length'] = str(body.tell())
            body.seek(0, 0)
        elif body is not None:
            self.headers['Content-Length'] = str(len(body))
=======
    def prepare_content_length(self, body):
        if hasattr(body, 'seek') and hasattr(body, 'tell'):
            body.seek(0, 2)
            length = body.tell()
            body.seek(0, 0)
        elif body is not None:
            length = len(body)
        else:
            length = None

        if length:
            self.headers['Content-Length'] = str(length)
        elif self.method not in ('GET', 'HEAD'):
            self.headers['Content-Length'] = '0'
>>>>>>> REPLACE