Command-Line Interface

errortools ships two CLI entry points: python -m errortools (or simply errortools after install) for package information and developer tooling, and logger for emitting log messages from the shell.

Installation

Both commands become available after installing the package:

pip install errortools

Note

After installation you can use the errortools and logger console scripts directly. The examples below show both forms interchangeably.

errortools command

Display package metadata and run the test suite.

Usage

errortools [OPTIONS]
# or, equivalently:
python -m errortools [OPTIONS]

Options

Option	Short	Description
--version	-v	Show version and exit
--copyrights	-c	Show copyright information
--author	-a	Show author name
--email	-e	Show author email
--license	-l	Show license type
--url	-u	Show project URL
--info	-i	Show all package information
--run-tests		Run the test suite using pytest

Examples

# Print version (matches the format used by --info)
$ errortools -v
errortools 3.4.9

# Print all metadata
$ errortools -i
errortools v3.4.9
  errortools - a toolset for working with Python exceptions and warnings and logging.
  Author:    Evan Yang <quantbit@126.com>
  License:   MIT
  URL:       https://github.com/more-abc/errortools
  Copyright: Copyright 2026 (C) aiwonderland Evan Yang

# Run the test suite
$ errortools --run-tests
...

logger command

Emit a single log message from the command line, or open an interactive debug shell, using the errortools structured logger.

Usage

logger <subcommand> [OPTIONS]

Subcommands

Subcommand	Description
emit	Emit a single log message to stdout or stderr
shell	Launch an interactive logger REPL debug shell

logger emit

logger emit MESSAGE [OPTIONS]

Options

Option	Short	Description
--level	-l	Log level: trace, debug, info, success, warning, error, critical (default: info)
--output	-o	Output stream: stderr or stdout (default: stderr)

Examples

# Info-level message (default) to stderr
$ logger emit "Deployment complete"

# Error-level message
$ logger emit "Connection failed" --level error

# Short flags
$ logger emit "Build started" -l info -o stdout

logger shell

Launch an interactive Python REPL with pre-imported logging shortcuts.

Examples

$ logger shell

errortools Logger Shell REPL 3.14.3 (tags/v3.14.3:323c59a, Feb  3 2026, 16:04:56) [MSC v.1944 64 bit (AMD64)] on win32
Pre-imported shortcuts: info, debug, error, warning, critical, trace, success, exception, catch
Pre-imported types: logger, Level, LEVELS, BaseLogger, Record, StreamSink, FileSink, CallableSink
Pre-imported std-lib: Logger, Handler, Filter, Formatter
Type "help", "copyright", "credits" or "license" for more information.
>>> info("Hello from the shell")
>>> debug("Variable x = {}", 42)
>>> with catch():
...     1 / 0

Mode detection

The errortools module dispatches between the two CLI families by inspecting the basename of sys.argv[0]. If it resolves to logger (with optional .exe / .py suffix), the logger dispatcher is used; otherwise the errortools dispatcher is used. This means paths such as my_logger_tool are no longer mistaken for the logger command.