Flake8 integrated with PyCharm

Flake8.txt

How to manually setup flake8 as PyCharm external tool

File / Settings / Tools / External Tools / Add
Name: Flake8
Program: $PyInterpreterDirectory$/python
Parameters: -m flake8 --max-complexity 10 --ignore E501 $FilePath$
Working directory: $ProjectFileDir$

Output Filters / Add
Name: Filter 1
Regular expression to match output:
$FILE_PATH$\:$LINE$\:$COLUMN$\:.*

Output Filters / Add
Name: Filter 2
Regular expression to match output:
$FILE_PATH$\:$LINE$\:.*

To check source with flake8:
Tools / External Tools / Flake8

Can be used with single files as well as with directories, recursively.

Hey there, I managed to configure WSP using LSP4IJ in PyCharm and good old pipx. I assume you have pipx.

Here's how

1 Install python-lsp-server

# Install pylsp
pipx install "python-lsp-server[flake8]"

# Inject required plugins
pipx inject python-lsp-server wemake-python-styleguide
pipx inject python-lsp-server pyls-flake8

Important: The [flake8] extra does NOT install the flake8 plugin — you must manually inject pyls-flake8.

2 Verify Installation.

pipx runpip python-lsp-server list
# or 
pipx runpip python-lsp-server list | grep -E "(flake8|wemake|pyls-flake8|Flake8-pyproject)"

Expected output:

flake8                    7.x.x
pyls-flake8               0.x.x
wemake-python-styleguide  1.x.x

3 Find pylsp Executable Path

where pylsp

Note the path: C:\Users\Day\.local\bin\pylsp.exe

4 Create LSP server

1. Settings → Languages & Frameworks → Language Server Protocol → Server Definitions
2. Click "+" to add a new server
3. Configure:

Field	Value
Name	pylsp-flake8
Path	C:\Users\Day\.local\bin\pylsp.exe

4. In the Configuration tab, add this JSON:

{
  "pylsp": {
    "plugins": {
      "flake8": {
        "enabled": true,
        "maxLineLength": 70,
        "select": ["WPS", "E"],
        "ignore": ["WPS111", "WPS602"]
      },
      "pycodestyle": {
        "enabled": false
      },
      "pyflakes": {
        "enabled": false
      }
    }
  }
}

or

{
  "pylsp": {
    "plugins": {
      "flake8": {
        "enabled": true,
        "config": "C:\\...whatever...\\.flake8"
      },
      "pycodestyle": { "enabled": false },
      "pyflakes": { "enabled": false },
      "mccabe": { "enabled": false },
      "pyls_isort": { "enabled": false },
      "pylsp_mypy": { "enabled": false },
      "rope_autoimport": { "enabled": false },
      "rope_completion": { "enabled": false }
    }
  }
}

5. In Mappings - Language - Languages add the Python language.

6. Click OK

5 Restart PyCharm

Restart PyCharm completely for the LSP server to initialize.

6 Test Inline Errors

Create a test file with intentional WPS errors:

# test_wps_errors.py
"""Test file with WPS errors."""

# WPS407: Mutable module constant
ITEMS_LIST = []

# WPS110: Wrong variable name
data = {"key": "value"}
obj = object()

def process(x):
    # WPS421: Wrong function call (print)
    print("Processing...")
    # WPS432: Magic number
    return x * 3.14159

• WPS errors appear as inline squiggles (yellow/orange underlines)
• Hovering shows the WPS error message