Replace everything but digits

Question

I have the following string:

s = Promo 77

I am trying to get the output "77".

The following is the regex I am using:

>>> re.sub(r'^[0-9]','',s)
'Promo 77'

What should the correct statement be here?

Have you tried `r'\d+'` for the regex? – shaktimaan Jul 15 '14 at 22:57 — shaktimaan, Jul 15 '14 at 22:57
`^[0-9]` should be `[^0-9]` in your regex. – elixenide Jul 15 '14 at 22:59 — elixenide, Jul 15 '14 at 22:59

score 4 · Accepted Answer · answered Jul 15 '14 at 22:57

4

>>> s = 'Promo 77'
>>> "".join(i for i in s if i.isdigit())
'77'

answered Jul 15 '14 at 22:57

Cory Kramer

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It's better to pass a list comprehension than a generator expression to `str.join`; see http://stackoverflow.com/q/9060653/3001761 – jonrsharpe Jul 15 '14 at 23:01

murgatroid99 · Answer 2 · 2014-07-16T00:58:12.670

2

You simply need to move the ^. r'^[0-9]' matches the beginning of the string, followed by a digit (which does not appear in your string). You want r'[^0-9]', which matches any character that is not a digit, or r'\D', which matches exactly the same set of characters.

edited Jul 16 '14 at 00:58

answered Jul 15 '14 at 22:58

murgatroid99

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You can also replace 0-9 with \d – ZJS Jul 16 '14 at 00:02
Actually, now that I think of it, `\D` is what I want. – murgatroid99 Jul 16 '14 at 00:57

Padraic Cunningham · Answer 3 · 2014-07-15T23:17:30.920

1

s = "Promo 77"
print re.findall("\d+",s)
['77']
print s.split()[-1]
77
re.sub(r'\D', "", s)
77
re.sub(r"[^\d+]","",s)
77

edited Jul 15 '14 at 23:17

answered Jul 15 '14 at 22:57

Padraic Cunningham

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Replace everything but digits

3 Answers3