Simple Floating Point regex

Question

I'm using [+-]?[0-9]*.[0-9]{1,} this simple regex for detecting simple floating numbers. It's working fine but it's detecting 4.0O0 as a floating point number. Can anyone explain me why ? i'm doing it using python , the code is given below:

    pattern=r'[+-]?[0-9]*\.[0-9]{1,}'
    input_float=input().strip()
    if re.match(pattern,input_float):
         print("True")
    else:
         print("False")

Possible duplicate of [Extract float/double value](https://stackoverflow.com/questions/385558/extract-float-double-value) — gaganso, Jul 18 '18 at 06:16
There is an upper-case 'o' (O) in your `4.0O0` - a typo in your question, or your data-source? — Tom Regner, Jul 18 '18 at 06:21
That's actually not a typo that was a test case that was supposed to get failed — Vineet Bhikonde, Jul 18 '18 at 06:42
Also i think it is better to modify the pattern as " r'[+|-]?[0-9]*\.[0-9]+' " , because with your pattern it will pass a test case like +-4.50 Which doesn't makes much sense! — Gaurav Parashar, May 25 '19 at 02:18

score 1 · Accepted Answer · answered Jul 18 '18 at 06:09

1

re.match only matches the given regex at the beginning of the string, but not the end of the string. Use re.fullmatch instead to match the entire string with the given regex.

if re.fullmatch(pattern,input_float):

answered Jul 18 '18 at 06:09

blhsing

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Simple Floating Point regex

1 Answers1