Black incorrectly formatting code - output has lines with more than 88 characters

Describe the bug Black is failing to format a Python snippet to conform with its own rules; in particular, the default 88 character limit is breached.

To Reproduce

1. Create a file with this Python code:

exclude_because_before = exclude_trips_before is not None and trip_stop_time.get_time().timestamp() <= current_time - float(
    exclude_trips_before
)

1. Run Black on it with no arguments.
2. Observe that nothing happens, even though the first line has 125 characters and so should be reformatted.

Expected behavior

The code is reformatted and all lines have 88 or fewer characters.

Environment (please complete the following information):

• Version: black-19.10b0
• OS and Python version: Mac OS Mojava 10.14.6 / Python 3.7

Does this bug also happen on master? Yes (checked using website)

[jaydamask]

I, too, am seeing lines rendered very long, well beyond PEP8 recommendations.

With line-length = 80 (could be anything reasonable), my PEP8 line renders as

    inline_slope_time_series = impulse_response_builder_tools. \
        compute_noncausal_symmetric_first_difference(
            reference_time_series
    )

However, with black I have

    inline_slope_time_series = impulse_response_builder_tools.compute_noncausal_symmetric_first_difference(
        reference_time_series
    )

Do scroll to the right… it’s long. While I’m all for black (I just blackified by codebase), this one is pretty wonky. black’s reluctance to use \ chars is fine, but respecting line lengths (-ish) should strongly contribute to the solver’s figure-of-merit calculation.

System details are:

• Python 3.7.5
• black, version 19.3b0
• Mac OS 10.15.1 (19B88)

I just confirmed this behavior on your black tip site.

Issues that are related, to greater or lesser degrees, appear to be: #1094, #951, #933, #917, #809, #664 and #510.

[rben01]

Not sure if I should make this a separate issue but I’m also seeing this type of issue with dicts whose strings and values are both very long string literals, and "key":"value" is longer than the max line length but "key":\n"value" would not be – black does not break the line at the colon, even though it should.