checking if year is in the string (4 consecutive digits)

Question

How can I find if a strings in a list contains a year (ex. 1999). I guess I would check for four consecutive digits such as: [1-2][0-9][0-9][0-9]

How to check that against a list piece? Here is what I’ve tried already

for piece in reflist:
    if "d{4}" in piece:
        # Do something

for piece in reflist:
    if re.match('d{4}', piece):
        print piece + 'n'

Asked By: raw-bin hood

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Source

Answer 1

You want to use re.search() to test for matches anywhere in the input string.

To match (recent) years a little more precisely, you could use:

re.search(r'[12]d{3}', piece)

which would match anything from 1000 through to 2999.

Answered By: Martijn Pieters

Answer 2

While both 'd{4}' and r'[12]d{3}' will return 4 consecutive digits, they will also return the first 4 digits of a larger number like 199999.

To get an occurrence of a year like the OP example of 1999, wrap the expression with s which will match for whitespace characters.

r's[12]d{3}s'

Answered By: pieguy

Answer 3

To add on to the answers above – 'r's[12]d{3}s' misses the edge case where the 4 digit number appears at the end of the string (because there is no space after the number). To capture those cases, use:

re.search('r's[12]d{3}s|s[12]d{3}$', piece)

Answered By: BGeez

checking if year is in the string (4 consecutive digits)

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