Read Python's base64.py source code

As a dabbler, I would like to be able to improve my posture level by reading the source code of base64.py. The code is about 600 lines, but given the recent tense, it may take a while for the code to be read.

Read a question about the code: I don't know what the __all__ variable is.

To the almighty Google on a check, found that __all__ main impact from XXX import * This command, if the source file does not have __all__, then use the command mentioned above will import all the variables in the source file into the current environment, if set up __all_ _ then only the specified variables are imported into the current environment.

Read Python's base64.py source code