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
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))
