Xguard is yet another guard clause library.
A guard clause is simply a check that immediately exits the function, either with a return statement or an exception. If you're used to writing functions that check to ensure everything is valid for the function to run, then you write the main function code, and then you write else statements to deal with error cases, this involves inverting your current workflow. The benefit is that your code will tend to be shorter and simpler, and less deeply indented. Credit
Using this package is easy. Just import the package, create an instance of the Xguard class, and start chaining your guard clauses together.
In dev mode, if you still encounter a lot of import errors, and you think you know what you are doing, try to add the xguard dir to the python path.
export PYTHONPATH=/path/to/parent/directory:$PYTHONPATH
Here's an example:
from xguard import guard
def add_ten(number: int):
guard = guard.Xguard()
guard.not_null(number) \
.is_type(number, int) \
.is_gt(number, 0)
# if we made it here, we have succeessfully used the guard clause, kudos!
return number + 10;
res: int = add_ten(5) # 120
print(res)
# Good Issue: Try to use the guard clauses in a factorial functionSee? Easy!
python -m unittest discover tests/I wrote xguard because I wanted to write a python library/module for fun
It was also an opporuinty for me to improve on a similar project by Adrian without wrecking his code. I am adding custom error messages to make it more usable and flexible. With custom error messages, developers can quickly understand what went wrong when a guard clause fails.
I believe in the power of open source software and I would love for others to contribute to this minimal/simple project. If you have any feedback or suggestions, please feel free to share them or open a issue.
Each guard method is documented with a docstring that explains its purpose and usage, following the reST style. You can access the documentation for each method using Python's built-in help function
This library is released under the GNU GPLv3 License. See the LICENSE file for details.
This library is based on the ideas and code of Adrian's similar project. Thank you, Adrian!