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small gist,to return a default value if the parameter is None

Project description


Version v1.1.15 as of 2023-07-14 see Changelog

build_badge codeql license jupyter pypi PyPI - Downloads black codecov Maintainability Maintainability Code Coverage snyk

small gist, to return a default value if the parameter is None

for mypy type annotation, the parameter usually has the type Optional[T], the returned type will have the type T

really not worth a package, just dont know where else to put it.

# definition
from typing import TypeVar, Optional

T = TypeVar('T')

def get_default_if_none(parameter: Optional[T], default: T) -> T:
    if parameter is None:
        return default
        return parameter
# usage
from typing import Optional
import lib_parameter

x: Optional[int] = None

x = lib_parameter.get_default_if_none(x, default=1)
# now x is from type int, not Optional[int]

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-dev, pypy-3.9, pypy-3.10 - 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

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


import the module and check the code - its easy and documented there, including doctest examples.
in case of any questions the usage section might be expanded at a later time

Usage from Commandline

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

  small gist,to return a default value if the parameter is None

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

  info  get program informations

Installation and Upgrade

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

python -m pip --upgrade pip
python -m pip --upgrade setuptools
  • to install the latest release from PyPi via pip (recommended):

python -m pip install --upgrade lib_parameter
  • to install the latest release from PyPi via pip, including test dependencies:

python -m pip install --upgrade lib_parameter[test]
  • to install the latest version from github via pip:

python -m pip install --upgrade git+
  • include it into Your requirements.txt:

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

# for the latest development version :
lib_parameter @ 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
$ cd lib_parameter
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
$ cd lib_parameter

# to run the tests:
$ make test

# to install the package
$ make install

# to clean the package
$ make clean

# uninstall the package
$ make uninstall


following modules will be automatically installed :

## Project Requirements


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


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


This software is licensed under the MIT license


  • 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


  • add codeql badge

  • move 3rd_party_stubs outside the src directory to ./.3rd_party_stubs

  • add pypy 3.10 tests

  • add python 3.12-dev tests


  • require minimum python 3.8

  • remove python 3.7 tests


  • introduce PEP517 packaging standard

  • introduce pyproject.toml build-system

  • remove mypy.ini

  • remove pytest.ini

  • remove setup.cfg

  • remove

  • remove .bettercodehub.yml

  • remove .travis.yml

  • update black config

  • clean ./tests/


2022-06-01: update to github actions checkout@v3 and setup-python@v3


2022-06-01: update github actions test matrix


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


2022-03-25: fix github actions windows test


  • fix “ test”


2021-11-21: service release
  • implement github actions

  • implement check for test environment on __init__


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


2020-08-08: service release
  • fix documentation

  • fix travis

  • deprecate pycodestyle

  • implement flake8


2020-08-07: fix wheels


2020-08-01: fix pypi deploy


2020-07-31: initial PyPi release

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