http.client content length

gistfile1.py

def _get_content_length(body, method):
    # Get the content-length based on the body. If the body is "empty", we
    # set Content-Length: 0 for methods that expect a body (RFC 7230,
    # Section 3.3.2). If the body is set for other methods, we set the
    # header provided we can figure out what the length is.
    if not body:
        # do an explicit check for not None here to distinguish between unset
        # and set but empty
        if method.upper() in _METHODS_EXPECTING_BODY or body is not None:
            return 0
        return

    if hasattr(body, 'read'):
        try:
            return os.fstat(body.fileno()).st_size
        except AttributeError:
            # is the object seekable?
            try:
                curpos = body.tell()
                body.seek(0, 2)
            except (TypeError, AttributeError):
                if self.debuglevel > 0:
                    print('Unable to determine size of %r' % body)
                return
            else:
                sz = body.tell()
                body.seek(curpos)
                return sz

    if hasattr(body, '__iter__'):
        try:
            # is body a string or bytes type, or another iterable of chars?
            ord(body[0])
        except TypeError:
            # are we looking at an iterable of ints?
            if isinstance(body[0], int):
                return len(body)
            # nope, this is likely an iterable of iterables
            return sum(len(line) for line in body)
        else:
            return len(body)