5 kyu

Context manager decorator

129Dundee
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  • trashy_incel Avatar

    the link in the description points to the docs for Python 2.7, which is quite ancient. it should be upgraded to more recent docs

  • niko13 Avatar

    Hello There, i am trying to do this kata but get stuck on when the with statement is executed

    i am not able to get to the enter method, even if i do my custom contextmanager...

    is there any tips you can provide ?

  • Voile Avatar

    The initial code for the kata is this:

    def contextmanager(f):
    def wrapper(*args, **kwargs):
        # your solution
    return wrapper

    which is misleading and wrong: context manager is only used as @contextmanager so wrapper should not have any arguments. The actual parameters are passed in later to the thing returned from the wrapper.

    • Dundee Avatar

      You are probably mixing together decorator taking args and not taking args. You would be right, if contextmanager would be called as a function, like this:

      def some_decorator(some_arg=None):
    def inner(func):
        def wrapper(*args, **kwargs):
            ...
            return func(*args, **kwargs)
        return wrapper
    return inner

@some_decorator()  # note the parentheses
def foo(x):
    print(x)

foo('aaa')

      However, you have to take args and kwargs in the wrapper if you use the decorator without args:

      def some_decorator(func):
    def wrapper(*args, **kwargs):
        ...
        return func(*args, **kwargs)
    return wrapper

@some_decorator  # no parentheses
def foo(x):
    print(x)

foo('aaa')
      Issue marked resolved by Dundee 4 years ago
  • Voile Avatar

    This kata needs random tests.

  • askurandrio Avatar

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  • andre-dasilva Avatar

    Really nice kata. would be nice if there were more test cases

  • Unnamed Avatar

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  • zellerede Avatar

    There could be more test cases, at least for nonempty function arguments.

  • adam-tokarski Avatar

    Thanks for this Kata. It's good to be aware of these possibilities!

  • minus7 Avatar

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