Text, on Python 2, includes bytes? · Issue #418 · python/typing (original) (raw)

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Description

• typing.Text, on Python 2, maps to unicode.
• unicode is automatically promoted to Union[str, unicode], see special rules in typeshed pyi typeshed#270

The combination of these two rules means that an annotation Text now includes bytes, on Python 2.

And indeed, the below type-checks, with both pytype and mypy --python-version=2.7:

import typing
def f(x):
  # (typing.Text) -> None
  pass
f(b"foo")

This seems a bit odd to me. It also means that we don't have a cross-version way to express "unicode string". Should Text not do the auto-promotion, so that it only stands for unicode itself, on Python 2?