regex for only numbers in string?

问题

I can't find the regex for strings containing only whitespaces or integers. The string is an input from user on keyboard. It can contain everything but \n (but it doesn't matter I guess), but we can focus on ASCII since it's supposed to be English sentences Here are some examples:

OK:

'1'
'2 3'
'   3 56 '
'8888888       333'
' 039'

not OK:

'a'
'4 e'
'874 1231 88 qqqq 99'
' shf ie sh f 8'

I have this which finds the numbers:

t = [int(i) for i in re.findall(r'\b\d+\b', text)]

But I can't get the regex. My regex is currently re.match(r'(\b\d+\b)+', text) but it doesn't work.

回答1:

>>> re.match(r'^([\s\d]+)$', text)

You need to put start (^) and end of line ($) characters in. Otherwise, the part of the string with the characters in will match, resulting in false positive matches

回答2:

How about something like this

^ *\d[\d ]*$

See demo at regex101

The pattern requires at least one digit to be contained.

回答3:

To match only a whitespace or a digit you could use:

^[ 0-9]+$

That would match from the beginning of the string ^ one or more whitespaces or a digit using a character class [ 0-9]+ until the end of the string $.

来源：https://stackoverflow.com/questions/50177113/regex-for-only-numbers-in-string