error-explainer

This is a project aimed at tool developers who want to create custom error checks provide better messages with improved location, accuracy and message quality for different errors in Python.

Some checks for syntax errors are provided out of the box.

Currently available checks can be found in error-explainer/messages.py

Installation

To install this package use pip install error-explainer

Usage

Check a Python file for possible errors

from error_explainer.check_runner import run_checks

messages = run_checks("path/to/file")

Messages will be a list of strings containing the generated messages.

Add a new custom check

Custom checks can be added to the list of checks ran while calling run_checks(). To add a new check use @add_check(force: bool, level=99) annotation. Force parameter defines if the check is ran only if the code does not compile (False) or always (True) Checks are also run in multiple levels from 0 to 99. Current layers are the following:

• 0 - docstring errors, quote errors
• 1 - miss match bracket errors, missing bracket errors, python 2 style print usage error
• 2 - invalid function definition errors
• 3 - missing colon errors, invalid assignment errors
• 99 - indentation errors, coma used instead of a period in an assignment error

from error_explainer.check_runner import add_check, add_message

@add_check(False)
def custom_check(filename):
    # code for the check  
    if error_in_file:
        # To add a message to the list of messages returned when calling run_checks() use 
        add_message("code_for_the_message", argument1="foo", argument2="bar")
        # Custom arguments can be used in the message text to make messages more dynamic

Manage messages

Messages used in checks can be:

added

from error_explainer.messages import add_message

# message text can contain arguments in curly brackets these can be later given values using kwargs
add_message("code_for_the_message", "Message text with {dynamic_arguments}")

removed

from error_explainer.messages import remove_message

remove_message("code_for_the_message")

overwritten

from error_explainer.messages import overwrite_message

overwrite_message("code_for_the_message", "Message text with {dynamic_arguments}")