Python: Ignore ‘Incorrect padding’ error when base64 decoding

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It seems you just need to add padding to your bytes before decoding. There are many other answers on this question, but I want to point out that (at least in Python 3.x) base64.b64decode will truncate any extra padding, provided there is enough in the first place.

So, something like: b'abc=" works just as well as b"abc==' (as does b'abc=====').

What this means is that you can just add the maximum number of padding characters that you would ever need—which is two (b'==')—and base64 will truncate any unnecessary ones.

This lets you write:

base64.b64decode(s + b'==')

which is simpler than:

base64.b64decode(s + b'=' * (-len(s) % 4))

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