Python 2 to 3

[chengshifan]

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

:white_check_mark: iberryful
:white_check_mark: chengshifan
:x: I517992

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