Why is an MD5 hash created by Python different from one created using echo and md5sum in the shell?
Question: A Python MD5 hash is different than the one created by the md5sum command on
the shell. Why?

    
    
    >>> import hashlib
    >>> h = hashlib.md5()
    >>> h.update("mystringforhash")
    >>> print h.hexdigest()
    86b6423cb6d211734fc7d81bbc5e11d3 # Result from Python
    
    
    $ echo mystringforhash | md5sum
    686687dd68c5de717b34569dbfb8d3c3  - # Result on the shell
    


Answer: `echo` appends a `\n` since you usually do not want lines not ending with a
linebreak in your shell (it looks really ugly if the prompt does not start at
the very left).  
Use the `-n` argument to omit the trailing linebreak and it will print the
same checksum as your python script:

    
    
    > echo -n mystringforhash | md5sum
    86b6423cb6d211734fc7d81bbc5e11d3  -
    

