https://www.python.org/dev/peps/pep-0635/#or-patterns

> There was some discussion on whether to use the bar symbol | or the or keyword to separate alternatives. The OR pattern does not fully fit the existing semantics and usage of either of these two symbols. However, | is the symbol of choice in all programming languages with support of the OR pattern and is used in that capacity for regular expressions in Python as well. It is also the traditional separator between alternatives in formal grammars (including Python's). Moreover, | is not only used for bitwise OR, but also for set unions and dict merging (PEP 584).

Еще | в описании типов можно использовать как видно из новости.

C && и || проблема в том, что легко ошибиться и написать один & или |, что в булевом контексте приведет сложноуловимой ошибке. Поэтому and и or.