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.
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
managers.
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.
Currently, Black does not split long strings to fit the line length limit. Currently, there is an experimental option to enable splitting strings. We plan to enable this option by default once it is fully stable. This is tracked in this issue.
Experimental, potentially disruptive style changes are gathered under the --preview
CLI flag. At the end of each year, these changes may be adopted into the default style,
as described in The Black Code Style.