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It improves the readability of the examples and help the reader
understand where objects come from.

See also See https://stackoverflow.com/a/2386740/1539918


Otherwise, from "The Zen of Python":

  Explicit is better than implicit.

See https://www.python.org/dev/peps/pep-0020/


Former-commit-id: 7c14bcd8

The following comment were executed:

pip install autopep8
autopep8 --in-place --max-line-length=150 -r .


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