In Python, single-quoted strings and double-quoted strings are the same. This PEP does not make a recommendation for this. Pick a rule and stick to it. When a string contains single or double quote characters, however, use the other one to avoid backslashes in the string. It improves readability.
For triple-quoted strings, always use double quote characters to be consistent with the docstring convention in PEP 257.
Это официальная документация pep8 на счет кавычек:
https://www.python.org/dev/peps/pep-0008/#string-quotes
Вот так на данном этапе.