The (future of the) Black code style¶
Changes to this document often aren’t tied and don’t relate to releases of Black. It’s recommended that you read the latest version available.
Using backslashes for with statements¶
Backslashes are bad and should be never be used however
there is one exception:
with statements using multiple context managers. Before Python
3.9 Python’s grammar does not allow organizing parentheses around the series of context
We don’t want formatting like:
with make_context_manager1() as cm1, make_context_manager2() as cm2, make_context_manager3() as cm3, make_context_manager4() as cm4: ... # nothing to split on - line too long
So Black will eventually format it like this:
with \ make_context_manager(1) as cm1, \ make_context_manager(2) as cm2, \ make_context_manager(3) as cm3, \ make_context_manager(4) as cm4 \ : ... # backslashes and an ugly stranded colon
Although when the target version is Python 3.9 or higher, Black will use parentheses instead since they’re allowed in Python 3.9 and higher.