Re: can you improve this text-only beginner copy program?

The suggestion (below) is good-practice. However, it's advanced-Python 
compared to the OP's first-course progress.

What is disappointing, is that instead of general strings as file-names 
the class has not been introduced to pathlib 
(https://docs.python.org/3/library/pathlib.html).

PS Ethan: way-down the docs you'll find two very handy methods worth 
applying as a second-attempt at this challenge!



On 28/08/25 03:41, Chris Angelico via Python-list wrote:
> On Thu, 28 Aug 2025 at 01:28, Ethan Carter <[email protected]> wrote:
>> def copy(s, d):
>>    """Copies text file named S to text file named D."""
>>    with open(s) as src:
>>      with open(d, "w") as dst:
>>        try:
>>          dst.write(src.read())
>>        except Exception:
>>          os.remove(d)
>>          raise
>>
> 
> In the event of an exception, you attempt to remove the destination
> file BEFORE exiting the `with` statement. While that might succeed on
> some platforms, it will potentially fail on others.
> 
> I would strongly recommend combining the two opens into a single with
> statement. If you can guarantee a minimum Python version of 3.10
> (released 2020, now in source-only-fix mode, so any fully supported
> version will indeed be >=3.10), you can write it like this:
> 
> with (open(s) as src,
>      open(d, "w") as dst):
> 
> or this:
> 
> with (
>      open(s) as src,
>      open(d, "w") as dst,
> ):
> 
> If you need to support older versions of Python, this would need to be
> done with backslashes, which is ugly, but still better (IMO) than
> using two nested context managers.
> 
> Out of curiosity, why do you have argc and argv? Seems a bit
> unnecessary. Python isn't C.
> 
> ChrisA

-- 
Regards,
=dn