la-catch 0.0.1

Decorator to map exception to functions

la-catch

Decorator to catch exception(s) and call function to handle the error. Can also define a return value to the function after catching.

install

pip install la-catch

syntax

@catch(exceptions, call, ret)

exceptions - Exception or Tuple of exceptions to be captured
call - function to be called in case of exceptions being raised
ret - value to be returned by the main function in case of exceptions being raised

call receives the same arguments from the decorated function but it appends the exception raised to the list of arguments (*args).
In case an exception is raised and no ret was defined, the return will be the same that call would return.

usages

Let's say that you just expect a function to try running something and if fails ignore and continue the program logic. In this case you just want to catch and ignore the exception:

from la_catch import catch


@catch(Exception)
def example():
    raise Exception("What a great day to raise an exception")

Most of times you want at least to print the exception, in this case you can pass a function to be called. This function will receive the exception as the last argument for you use as you like.

from la_catch import catch


def func(e):
    print("Look what i catched mommy:", e)


@catch(Exception, func)
def example():
    raise Exception("You will never catch me alive")

If all that you want is print the exception/traceback, i would recommend you passing logging.exception as call.

from la_catch import catch


@catch(Exception, logging.exception)
def example():
    raise Exception("I love to read tracebacks")

Let's say that you know how to deal with the raised problem, now you want the function to return the solution of the problem. You can make call return the expected resolution.

from la_catch import catch


def func(e):
    if isinstance(e, ZeroDivisionError):
        print("You can't divide by zero you dummy")
        return 0
    return 1


@catch(Exception, func)
def example():
    return 0/0

Okay okay, but now you want to log the exception and return something so you program doesn't crash. Better than creating a function just for this two things is passing to ret the value to return in case of this exception.

from la_catch import catch


@catch(Exception, logging.exception, 0)
def example():
    return 0/0

Of course that i am using Exception everywhere but you could use other exception or multiple exceptions!

from la_catch import catch


@catch((ZeroDivisionError, OverflowError, FloatingPointError), logging.exception, 0)
def example():
    return 0/0

If you want to make different things to different exceptions just decorate with one more catch.

from la_catch import catch


@catch(OverflowError, logging.exception, None)
@catch(ZeroDivisionError, logging.exception, 0)
def example():
    return 0/0

Just remember that exception is always pass as the last argument from call.

from la_catch import catch


def func(a, b, e):
    print("I have zero tolerance for this error... got it?")


@catch(ZeroDivisionError, func, 0)
def example(a, b):
    return a/b