blacken-selection 0.1.3

Apply black formatter for a piece of python source code

A tool that applies the Black python source code formatter to a single piece of python source code instead of a whole file or project.

Usage

$ pip install blacken-selection
$ blacken-selection -h
usage: Apply the black code formatter for a piece of python source code

positional arguments:
  SOURCE                The python source code to be formatted. If not
                        provided then source is read from stdin.

optional arguments:
  -h, --help            show this help message and exit
  -l LINE_LENGTH, --line-length LINE_LENGTH
                        How many characters per line to allow. [default: 88]
$ blacken-selection "def main(): pass"
def main():
    pass

Usage from PyCharm on linux

Unfortunately PyCharm External Tools cannot be used directly. The $SelectedText$ macro passes the selection as a command line argument to the tool but there is no way to properly quote a python string using double quotes.

But there is a solution:

• Install the xclip command line tool, we will use it to grab the code selection in PyCharm via the clipboard
• Install blacken_selection as described above
• Grab the simple shell script blacken-selection-xclip.sh

Setup blacken-selection-xclip.sh as an external tool in PyCharm:

File -> Settings -> Tools -> External Tools

Click the + icon to add a new external tool with the following values:

    Name: blacken
    Description: Blacken a piece of python code
    Program: <absolute path for your blacken-selection-xclip.sh>
    Arguments:

Select a piece of python source code in your editor and from the right click context menu select:

External Tools -> blacken