Skip to content

bpo-29974: Change typing.TYPE_CHECKING doc example #982

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
berkerpeksag merged 1 commit into from
Apr 26, 2017
Merged

bpo-29974: Change typing.TYPE_CHECKING doc example #982

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 7 additions & 2 deletions Doc/library/typing.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1005,5 +1005,10 @@ The module defines the following classes, functions and decorators:
if TYPE_CHECKING:
import expensive_mod

def fun():
local_var: expensive_mod.some_type = other_fun()
def fun(arg: 'expensive_mod.SomeType') -> None:
local_var: expensive_mod.AnotherType = other_fun()

Note that the first type annotation must be enclosed in quotes, making it a
"forward reference", to hide the ``expensive_mod`` reference from the
interpreter runtime. Type annotations for local variables are not
evaluated, so the second annotation does not need to be enclosed in quotes.