cli-exit-tools 1.2.7

functions to exit an cli application properly

cli_exit_tools

Version v1.2.7 as of 2024-10-02 see Changelog

small toolset to properly exit a cli application:

• print the traceback information (can be set with commandline option)

• get a proper exit code from the Exception

• flush the streams, to make sure output is written in proper order

• demo how to integrate into Your cli module (see usage)

---

automated tests, Github Actions, Documentation, Badges, etc. are managed with PizzaCutter (cookiecutter on steroids)

Python version required: 3.8.0 or newer

tested on recent linux with python 3.8, 3.9, 3.10, 3.11, 3.12, pypy-3.9, pypy-3.10, graalpy-24.1 - architectures: amd64

100% code coverage, flake8 style checking ,mypy static type checking ,tested under Linux, macOS, Windows, automatic daily builds and monitoring

---

• Try it Online

• Usage

• Usage from Commandline

• Installation and Upgrade

• Requirements

• Acknowledgements

• Contribute

• Report Issues

• Pull Request

• Code of Conduct

• License

• Changelog

---

Try it Online

You might try it right away in Jupyter Notebook by using the “launch binder” badge, or click here

Usage

• example for the main_cli

# STDLIB
import platform
import signal
import sys
from typing import Any
from typing import Callable
from typing import Optional
from typing import Union
from types import FrameType

# EXT
import click

# CONSTANTS
CLICK_CONTEXT_SETTINGS = dict(help_option_names=["-h", "--help"])

try:
    from . import __init__conf__
    from . import cli_exit_tools
except (ImportError, ModuleNotFoundError):  # pragma: no cover
    # imports for doctest
    import __init__conf__  # type: ignore  # pragma: no cover
    import cli_exit_tools  # type: ignore  # pragma: no cover

is_platform_windows = platform.system().lower() == "windows"
is_platform_linux = platform.system().lower() == "linux"
is_platform_darwin = platform.system().lower() == "darwin"
is_platform_posix = not is_platform_windows


class SigIntError(Exception):
    """wird bei Signal SigInt ausgelöst"""
    pass


class SigTermError(Exception):
    """wird bei Signal SigTerm ausgelöst"""
    pass


if is_platform_windows:
    """import win32 api on windows systems"""
    try:
        import win32api  # type: ignore # noqa
    except ModuleNotFoundError:  # for install_python_libs_python3.py - at that time pywin32 (win32api) might not be installed
        pass


def _set_signal_handlers() -> None:
    """
    setzt die signal handler so, das entsprechende Exceptions geraised werden.
    Dies dient dazu ein sauberes Handling für Cleanup in den Applikationen
    zu gewährleisten
    """
    # sigterm handler setzen
    if is_platform_linux:
        signal.signal(signal.SIGTERM, _sigterm_handler)
    elif is_platform_windows:
        try:
            win32api.SetConsoleCtrlHandler(_sigterm_handler, True)
        except NameError:  # for install_python_libs_python3.py - at that time pywin32 (win32api) might not be installed
            pass

    # sigint handler setzen
    signal.signal(signal.SIGINT, _sigint_handler)


def _sigint_handler(_signo: int, _stack_frame: Optional[FrameType]) -> None:
    raise SigIntError


def _sigterm_handler(_signo: int, _stack_frame: Optional[FrameType]) -> None:
    raise SigTermError


def info() -> None:
    """
    >>> info()
    Info for ...

    """
    __init__conf__.print_info()


@click.group(help=__init__conf__.title, context_settings=CLICK_CONTEXT_SETTINGS)    # type: ignore
@click.version_option(
    version=__init__conf__.version, prog_name=__init__conf__.shell_command, message=f"{__init__conf__.shell_command} version {__init__conf__.version}"
)
@click.option("--traceback/--no-traceback", is_flag=True, type=bool, default=None, help="return traceback information on cli")
def cli_main(traceback: Optional[bool] = None) -> None:
    if traceback is not None:
        cli_exit_tools.config.traceback = traceback


@cli_main.command("info", context_settings=CLICK_CONTEXT_SETTINGS)  # type: ignore
def cli_info() -> None:
    """get program information"""
    info()


# entry point if main
if __name__ == "__main__":
    try:
        _set_signal_handlers()
        cli_main()      # type: ignore
    except Exception as exc:
        cli_exit_tools.print_exception_message()
        sys.exit(cli_exit_tools.get_system_exit_code(exc))
    finally:
        cli_exit_tools.flush_streams()

• get the system exit code

def get_system_exit_code(exc: BaseException) -> int:
    """
    Return the exit code for linux or Windows os, based on the exception.
    If, on windows, the winerror code is passed with the Exception, we return that winerror code.


    Parameter
    ---------
    exc
        the exception to analyze


    Result
    ------
    exit_code
        as integer


    Examples
    --------

    >>> try:
    ...     raise RuntimeError()
    ... except RuntimeError as my_exc:
    ...     assert get_system_exit_code(my_exc) == 1
    ...     setattr(my_exc, 'winerror', 42)
    ...     assert get_system_exit_code(my_exc) == 42
    ...     setattr(my_exc, 'winerror', None)
    ...     assert get_system_exit_code(my_exc) == 1
    >>> try:
    ...     exit(99)
    ... except SystemExit as my_exc:
    ...     assert get_system_exit_code(my_exc) == 99

    """

• print the exception message

def print_exception_message(trace_back: bool = config.traceback, length_limit: int = 500, stream: Optional[TextIO] = None) -> None:
    """
    Prints the Exception Message to stderr. If trace_back is True, it also prints the traceback information.
    If the exception has stdout, stderr attributes (like subprocess.CalledProcessError), those will also be printed.

    Parameters
    ----------
    trace_back : bool, optional
        Whether to print traceback information. Default is False.
    length_limit : int, optional
        Maximum length of the exception message to be printed. Default is 500.
    stream : Optional[TextIO], optional
        The stream to print to. Default is sys.stderr.

    Examples
    --------

    >>> # test with exc_info = None
    >>> print_exception_message()

    >>> # test with exc_info
    >>> try:
    ...     raise FileNotFoundError('unknown_command_test1')
    ... except Exception:       # noqa
    ...     print_exception_message(True, length_limit=15, stream=sys.stdout)
    ...     print_exception_message(False, stream=sys.stdout)
    ...     print_exception_message(True, stream=sys.stdout)
    Traceback Info...

    >>> # test with subprocess to get stdout, stderr
    >>> import subprocess
    >>> try:
    ...     discard=subprocess.run('unknown_command_test2', shell=True, check=True)
    ... except subprocess.CalledProcessError:
    ...     print_exception_message(False, stream=sys.stdout)
    ...     print_exception_message(True, stream=sys.stdout)
    ...     print_exception_message(True, stream=sys.stdout)
    CalledProcessError...

    """

• flush the streams

def flush_streams() -> None:
    """
    flush the streams - make sure the output is written early,
    otherwise the output might be printed even after another CLI
    command is launched


    Examples
    --------


    >>> flush_streams()

    """

Usage from Commandline

Usage: cli_exit_tools [OPTIONS] COMMAND [ARGS]...

  functions to exit an cli application properly

Options:
  --version                     Show the version and exit.
  --traceback / --no-traceback  return traceback information on cli
  -h, --help                    Show this message and exit.

Commands:
  info  get program information

Installation and Upgrade

• Before You start, its highly recommended to update pip:

python -m pip --upgrade pip

• to install the latest release from PyPi via pip (recommended):

python -m pip install --upgrade cli_exit_tools

• to install the latest release from PyPi via pip, including test dependencies:

python -m pip install --upgrade cli_exit_tools[test]

• to install the latest version from github via pip:

python -m pip install --upgrade git+https://github.com/bitranox/cli_exit_tools.git

• include it into Your requirements.txt:

# Insert following line in Your requirements.txt:
# for the latest Release on pypi:
cli_exit_tools

# for the latest development version :
cli_exit_tools @ git+https://github.com/bitranox/cli_exit_tools.git

# to install and upgrade all modules mentioned in requirements.txt:
python -m pip install --upgrade -r /<path>/requirements.txt

• to install the latest development version, including test dependencies from source code:

# cd ~
$ git clone https://github.com/bitranox/cli_exit_tools.git
$ cd cli_exit_tools
python -m pip install -e .[test]

• via makefile: makefiles are a very convenient way to install. Here we can do much more, like installing virtual environments, clean caches and so on.

# from Your shell's homedirectory:
$ git clone https://github.com/bitranox/cli_exit_tools.git
$ cd cli_exit_tools

# to run the tests:
$ make test

# to install the package
$ make install

# to clean the package
$ make clean

# uninstall the package
$ make uninstall

Requirements

following modules will be automatically installed :

## Project Requirements
click
lib_detect_testenv

Acknowledgements

• special thanks to “uncle bob” Robert C. Martin, especially for his books on “clean code” and “clean architecture”

Contribute

I would love for you to fork and send me pull request for this project. - please Contribute

License

This software is licensed under the MIT license

—

Changelog

• new MAJOR version for incompatible API changes,

• new MINOR version for added functionality in a backwards compatible manner

• new PATCH version for backwards compatible bug fixes

v1.2.7

2024-10-02:

• setup-python@v5

• sigterm_handler for CLI

• graalpy 24.1 tests

• CODECOV_TOKEN

• refractor

v1.2.6

2023-07-14:

• add codeql badge

• move 3rd_party_stubs outside the src directory

• add pypy 3.10 tests

• add python 3.12-dev tests

v1.2.5

2023-07-13:

• require minimum python 3.8

• remove python 3.7 tests

v1.2.4

2023-07-12:

• introduce PEP517 packaging standard

• introduce pyproject.toml build-system

• remove mypy.ini

• remove pytest.ini

• remove setup.cfg

• remove setup.py

• remove .bettercodehub.yml

• remove .travis.yml

• update black config

• clean ./tests/test_cli.py

v1.2.3.2

2022-06-02: update to github actions checkout@v3 and setup-python@v3

v1.2.3.1

2022-06-01: update github actions test matrix

v1.2.3

2022-03-29: remedy mypy Untyped decorator makes function “cli_info” untyped

v1.2.2

2022-03-25: fix github actions windows test

v1.2.1

2021-11-22: Patch Release

• fix minor readme.rst bugs

• remove second github action yml

• fix “setup.py test”

v1.2.0

2021-11-21: Minor Release

• implement github actions

• implement system.exit()

v1.1.8

2020-10-09: service release

• update travis build matrix for linux 3.9-dev

• update travis build matrix (paths) for windows 3.9 / 3.10

v1.1.7

2020-08-08: service release

• fix documentation

• fix travis

• deprecate pycodestyle

• implement flake8

v1.1.6

2020-08-07: fix wheels

v1.1.5

2020-07-31: fix wheels

v1.1.3

2020-07-31: initial release