Why does PyCharm use 120 Character Lines even though PEP8 Specifies 79?

Question

PEP8 clearly specifies 79 characters, however, PyCharm defaults to 120 and gives me the warning "PEP8: line too long (... > 120 characters)".

Did previous versions of PEP8 use 120 and PyCharm not update its PEP8 checker? I couldn't find any previous versions of the PEP8 Guide, however, I can easily find previous version of the PEP8 Python scripts.

I'm starting a new Python project and I'm not sure which to use.

References:

http://legacy.python.org/dev/peps/pep-0008/

Solution 1

PyCharm is built on top of IntelliJ. IntelliJ has a default line length of 120 characters.

This is probably because you can't fit a common Java name like: @annotated public static MyObjectFactoryFactory enterpriseObjectFactoryFactoryBuilderPattern { in a mere 80 character line. (I'm poking fun, but Java names do tend to be longer by convention).

The pep8 checker is configurable, so you can specify a better max line length - like 79 characters.

The error is misleading because the pep8 checker formats the text with something like "PEP8: line too long(... > %s characters)" % max_line_setting. So it's using the pep8 checker, with a specific configuration, not claiming that pep8 specifies a 120 character line.

Solution 2

If you want to remove the limit warning altogether you can take the following steps:

1. In PyCharm, click File > Settings
2. In the project settings section, click Editor > Inspections
3. In the list that appears, expand Python
4. Under Python, scroll down and click "PEP8 coding style violation"
5. Click the + button next to "Ignore errors" in the bottom right
6. Type out E501 and click Apply and/or OK

Sources:

• http://iambigblind.blogspot.com/2013/02/configuring-pep8py-support-in-pycharm-27.html

• https://intellij-support.jetbrains.com/hc/en-us/community/posts/205816889-Disable-individual-PEP8-style-checking-line-length-