Command Line Interface¶
The command line interface of Flake8 is modeled as an application via
Application. When a user runs
flake8 at their
main() is run which handles
management of the application.
User input is parsed twice to accommodate logging and verbosity options passed by the user as early as possible. This is so as much logging can be produced as possible.
The default Flake8 options are registered by
register_default_options(). Trying to register
these options in plugins will result in errors.
Main entry-point for the flake8 command-line tool.
This handles the creation of an instance of
Application, runs it, and then exits the application.
Parameters: argv (list) – The arguments to be passed to the application for parsing.
Abstract our application into a class.
The left over arguments that were not parsed by
Whether or not something catastrophic happened and we should exit with a non-zero status code
The timestamp when the Application finished reported errors.
Handle finalization and exiting the program.
This should be the last thing called on the application instance. It will check certain options and exit appropriately.
flake8.checker.Managerthat will handle running all of the checks selected by the user.
Find and load the plugins for this application.
Nonethen this method will update them with the appropriate plugin manager instance. Given the expense of finding plugins (via
pkg_resources) we want this to be idempotent and so only update those attributes if they are
The user-selected formatter from
flake8.style_guide.StyleGuidebuilt from the user’s options
Initialize the application to be run.
This finds the plugins, registers their options, and parses the command-line arguments.
Initialize our FileChecker Manager.
Initialize a formatter based on the parsed options.
Initialize our StyleGuide.
Initialize our listener Notifier.
The instance of
flake8.options.manager.OptionManagerused to parse and handle the options and arguments passed by the user
The user-supplied options parsed into an instance of
Parse configuration files and the CLI options.
Parameters: argv (list) – Command-line arguments passed in directly.
The parsed diff information
The name of the program being run
Register options provided by plugins to our option manager.
Report errors, statistics, and benchmarks.
Aggregate, calculate, and report benchmarks for this run.
Report all the errors found by flake8 3.0.
This also updates the
result_countattribute with the total number of errors, warnings, and other messages found.
Aggregate and report statistics from this run.
The number of errors, warnings, and other messages after running flake8 and taking into account ignored errors and lines.
Run our application.
This method will also handle KeyboardInterrupt exceptions for the entirety of the flake8 application. If it sees a KeyboardInterrupt it will forcibly clean up the
Run the actual checks with the FileChecker Manager.
This method encapsulates the logic to make a
Mangerinstance run the checks it is managing.
Parameters: files (list) – List of filenames to process
Whether the program is processing a diff or not
The timestamp when the Application instance was instantiated.
The total number of errors before accounting for ignored errors and lines.
The version of the program being run
Register the default options on our OptionManager.
The default options include: