Pre-processing Sha256 Python Implementation

I am working my way through the SHA256 implementation on wikipedia but have came up stuck. I have just tried to write the code for the message pre-processing and my length for the

Solution 1:

There are two problems:

1) The 488 magic number in your code should be 448.

2) You're only using 16 "bits" (characters) in append_length_of_message().

HIH!

Solution 2:

If you are considering hex as a variable, then

hex = format(len(input_string),'x')

should be updated to

hex = format(len(input_string),'b')

to get the correct result.

By doing this the result will become with respect to SHA.