Deciding between while and for

[ablech]

Description

In the config module in line 208 the following construct is used, referring to PEP 479:

while True:
    try:
        raw_line = next(raw_lines)
    except StopIteration:
        return
    
    # do stuff

This seems to be equivalent to

for raw_line in raw_lines:
    # do stuff

Is there a reason, why the while construct should be preferred in such a situation?
Under which circumstances does this apply?

[goerz]

No, that wouldn't work: the loop body can consume more than one raw_line: there's a next(raw_lines) a little farther below. This is because continuation-lines get combined.

I'll add a comment to clarify this.

In general, the easiest way to answer this question besides just looking at the code would be to resolve #6, and test the config file reader to oblivion with the most pathological files you can think of: then you can change the code and test whether it still works.

[ablech]

Oh, sorry, I overlooked this. Thanks!

[goerz]

No reason to be sorry! It’s an unusual construct, which should have an explanation