How to escape strings for re.finditer?

[Jen Kris]

Using str.startswith is a cool idea in this case.  But is it better than regex for performance or reliability?  Regex syntax is not a model of simplicity, but in my simple case it's not too difficult.  


Feb 27, 2023, 18:52 by list1 at tompassin.net:

> On 2/27/2023 9:16 PM, avi.e.gross at gmail.com wrote:
>
>> And, just for fun, since there is nothing wrong with your code, this minor change is terser:
>>
>>>>> example = 'X - abc_degree + 1 + qq + abc_degree + 1'
>>>>> for match in re.finditer(re.escape('abc_degree + 1') , example):
>>>>>
>> ...     print(match.start(), match.end())
>> ...
>> ...
>> 4 18
>> 26 40
>>
>
> Just for more fun :) -
>
> Without knowing how general your expressions will be, I think the following version is very readable, certainly more readable than regexes:
>
> example = 'X - abc_degree + 1 + qq + abc_degree + 1'
> KEY = 'abc_degree + 1'
>
> for i in range(len(example)):
>  if example[i:].startswith(KEY):
>  print(i, i + len(KEY))
> # prints:
> 4 18
> 26 40
>
> If you may have variable numbers of spaces around the symbols, OTOH, the whole situation changes and then regexes would almost certainly be the best approach.  But the regular expression strings would become harder to read.
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>