pyerr

Package providing functional error handling.


Keywords
error, handling, functional, error-handling, functional-programming, python
License
MIT
Install
pip install pyerr==0.1.0

Documentation

PyErr

Package providing functional error handling.

Description

Package providing functional error handling in 'monadic'-like way. Allows you to create wrapped value from success value or an error, apply functions to wrapped value and unwrap.

Install

pip install pyerr

Pypi link

Usage

Creating wrapped value

import pyerr

def plus_one(number_positive):
    if number_positive < 0:
        return pyerr.error("Number has to be positive.")
    else:
        return pyerr.ok(number_positive + 1)

Checking and unwrapping

...
result = plus_one(1)
if is_ok(result):
    print(f"Yay! we got result {unwrap(result)}")
else:
    print(f"Nay:( we got an error {unwrap(result)}")

Other examples

Handling function which could raise Exception with decorator

@pyerr.try_err
def plus_one(number_positive):
    if val_int < 0:
        raise Exception("Number has to be positive.")
    else:
        return pyerr.ok(number_positive + 1)

result_ok = target(1)
result_err = target(-1)

Applying functions to wrapped value

# Applying general function
wrapped_result = pyerr.fmap(lambda x: x + 1, pyerr.ok(1))

# Applying function that returs wrapped value from pyerr
flat_wrapped_result = pyerr.flat_map(lambda x: pyerr.ok(x+1), pyerr.ok(1))