How to use re.search starting from a specific index in a row?

Question

Sounds like a simple thing, but I don't see it. How to start a search in the middle of a line?

Answer 1

The function re.searchdoes not accept an argument start, as methods do str. But searchthe compiled template re.compile/ method re.RegexObjecttakes an argument pos.

It makes sense if you think about it. If you really need to use the same regular expressions over and over again, you probably should compile them. Not so much for efficiency - the cache works well for most applications, but only for readability.

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i = 0
while True:
    i = s.find(sub, i)
    if i == -1:
        break
    do_stuff_with(s, i)

... :

for match in re.finditer(pattern, s):
    do_stuff_with(match)

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match = re.search(pattern, s[index:])

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match = re.search('.{%d}%s' % (index, pattern), s)

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.{3}(abc)

Debuggex

abcdefabcdef, 'abc' , abc.

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