What’s the notation for any number in re? Like if I’m searching a string for any number, positive or negative. I’ve been using d+ but that can’t find 0 or -1
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Answer
Searching for positive, negative, and/or decimals, you could use [+-]?d+(?:.d+)?
>>> nums = re.compile(r"[+-]?d+(?:.d+)?") >>> nums.search("0.123").group(0) '0.123' >>> nums.search("+0.123").group(0) '+0.123' >>> nums.search("123").group(0) '123' >>> nums.search("-123").group(0) '-123' >>> nums.search("1").group(0) '1'
This isn’t very smart about leading/trailing zeros, of course:
>>> nums.search("0001.20000").group(0) '0001.20000'
Edit: Corrected the above regex to find single-digit numbers.
If you wanted to add support for exponential form, try [+-]?d+(?:.d+)?(?:[eE][+-]?d+)?
:
>>> nums2 = re.compile(r"[+-]?d+(?:.d+)?(?:[eE][+-]?d+)?") >>> nums2.search("-1.23E+45").group(0) '-1.23E+45' >>> nums2.search("0.1e-456").group(0) '0.1e-456' >>> nums2.search("1e99").group(0) '1e99'