Pylama

Common errors

• Pylint doesn't exist

  cause The Pylint linter, while wrapped by Pylama, is not installed by default and needs to be installed separately or via the `pylama_pylint` module for Pylama to use it.
  fix Install Pylint alongside Pylama: `pip install pylama pylint` or `pip install pylama_pylint` if a dedicated integration package is preferred/required.

• Incorrectly sorted imports. [isort]

  cause The `isort` linter is available through Pylama but is not enabled by default. If `isort` is installed and you expect Pylama to report on import sorting, it needs to be explicitly configured.
  fix Enable `isort` in your Pylama configuration file (`pylama.ini`) by adding `linters = isort` or specifying it on the command line: `pylama --linters=isort <path>`.

• mypy output is visible in the "Output tab", but not in the "Problems" tab.

  cause This often occurs when using Pylama with IDE extensions (like in VS Code) where the parsing of Pylama's aggregated output for specific linters (like Mypy) is not correctly mapped to the IDE's 'Problems' panel.
  fix Check the documentation for your IDE's Python extension for Pylama output parsing configurations. Sometimes, updating the extension or using a specific output format for Pylama (e.g., `--format pep8` or `--format pylint`) might resolve the issue.

• FileNotFoundError: [Errno 2] No such file or directory: 'some/path/file.py'

  cause This typically happens when Pylama is configured to check a path that does not exist or is inaccessible in the current environment, often due to incorrect relative paths in configuration files or CI/CD pipelines.
  fix Verify that all paths specified in Pylama commands or configuration files (`pylama.ini`, `setup.cfg`, etc.) are correct and accessible from where Pylama is being executed. Use absolute paths if there's ambiguity with relative paths.

Warnings

• breaking Pylama dropped support for Python 2.x. It now requires Python 3.7 or newer. Older Python versions need Pylama 7.7.1 or earlier.
  Fix: Upgrade your Python environment to 3.7+ or pin Pylama to version <=7.7.1 for Python 2.x projects.
• breaking The `--force` option, which allowed Pylama to check non-Python files, was removed. By default, Pylama now only checks Python files.
  Fix: Ensure you are only passing Python files to Pylama, or consider alternative tools for non-Python file auditing.
• gotcha When using the 'mccabe' linter, the argument for complexity was renamed from `complexity` to `max-complexity`.
  Fix: Update your Pylama configuration (e.g., `pylama.ini`) to use `max-complexity` instead of `complexity` for mccabe settings.
• gotcha Pylama's integration with Pylint can be sensitive to Pylint's internal changes. Specifically, Pylint 2.8.0 temporarily removed `__pkginfo__.numversion`, causing issues with Pylama. While `numversion` was temporarily re-added in Pylint 2.8.1, ensure compatibility.
  Fix: Ensure you are using a compatible version of Pylint (e.g., Pylint >= 2.8.1) or explicitly install `pylama_pylint` if available for better integration.

Install

• pip install pylama Basic Installation
• pip install pylama[toml] With TOML configuration support
• pip install pylama[mypy] With Mypy linter support
• pip install pylama pylint With Pylint (requires separate install)

Imports

• check_path

  from pylama.main import check_path

• parse_options

  from pylama.main import parse_options

• Linter

  from pylama.lint import Linter

  Used for writing custom linters.

Quickstart

The primary way to use Pylama is via the command line, running `pylama` in your project's root or specifying files/directories. For programmatic use, you can import `check_path` and `parse_options` from `pylama.main` to analyze files and retrieve issues directly within Python code. This example demonstrates creating a temporary file with known issues, running `pylama` on it, and printing the reported errors.

import os
import textwrap
from pylama.main import check_path, parse_options

# Create a dummy Python file to check
file_content = textwrap.dedent('''
    import os, sys

    def my_function():
        x=10 # E225 missing whitespace around operator
        if x > 5:
            print("Hello")
        return "world"

    my_function() # W0612 unused variable 'x'
''')

file_path = "./temp_pylama_test.py"
with open(file_path, "w") as f:
    f.write(file_content)

# Run pylama programmatically
# Options can be passed as a dictionary
options_dict = {
    'linters': ['pycodestyle', 'pyflakes'], # Specify linters to use
    'ignore': ['W0611'], # Ignore specific warnings, e.g., unused imports
    'select': []
}

# parse_options processes paths and dictionary options into an options object
options = parse_options([file_path], **options_dict)
errors = check_path(options)

if errors:
    print(f"Found {len(errors)} issues in {file_path}:")
    for error in errors:
        print(f"  {error.filename}:{error.lnum}:{error.col} [{error.type}] {error.text} [{error.linter}]")
else:
    print(f"No issues found in {file_path}.")

# Clean up the dummy file
os.remove(file_path)