Find x-digit number in a text using Python

问题

Is there a better (more efficient) way to find x-digit number (number consisted of x digits) in a text?

My way:

EDIT:

for n in range(0,len(text)):
    if  isinstance(text[n:n+x], (int)) and isinstance(text[n:n+x+1] is False:
        result = text[n:n+x]

return result

EDIT 2:

for n in range(0,len(text)):
    try:  
       int(text[n:n+x])
       result = text[n:n+x]
    except:
       pass

return result

回答1:

import re                                             
string = "hello 123 world 5678 897 word"              
number_length = 3                                     
pattern= r"\D(\d{%d})\D" % number_length   # \D to avoid matching 567           
print re.findall(pattern, string)

output

["123","897"]

回答2:

You could use regex to achieve that. For example

>>> import re

>>> s = "abc 123 45678"
>>> re.search("(\d{5})\D",s).group()
'45678'

finds a 5 digit number in s. Or if you have multiple numbers use findall

>>> s = "abc 123 45678\nbla foo 65432"
>>> re.findall("(\d{5})\D",s)
['45678', '65432']

回答3:

exampleText = "abcd12345xyz"

import re

match = re.search('\d+',exampleText)
print(match.group())

来源：https://stackoverflow.com/questions/25532877/find-x-digit-number-in-a-text-using-python