A "scopeguard" for Python

[Robert Kern]

On 2010-03-03 09:39 AM, Mike Kent wrote:
> What's the compelling use case for this vs. a simple try/finally?
>
>     original_dir = os.getcwd()
>     try:
>         os.chdir(somewhere)
>         # Do other stuff
>     finally:
>         os.chdir(original_dir)
>         # Do other cleanup

A custom-written context manager looks nicer and can be more readable.

from contextlib import contextmanager
import os

@contextmanager
def pushd(path):
     original_dir = os.getcwd()
     os.chdir(path)
     try:
         yield
     finally:
         os.chdir(original_dir)


with pushd(somewhere):
     ...


I don't think a general purpose ScopeGuard context manager has any such benefits 
over the try: finally:, though.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco