python regex: get end digits from a string

Question

I am quite new to python and regex (regex newbie here), and I have the following simple string:

s=r\"\"\"99-my-name-is-John-Smith-6376827-%^-1-2-767980716\"\         


        

Answer 1

Use the below regex

\d+$

$ depicts the end of string..

\d is a digit

+ matches the preceding character 1 to many times

Answer 2

Try using \d+$ instead. That matches one or more numeric characters followed by the end of the string.

Answer 3

You can use re.match to find only the characters:

>>> import re
>>> s=r"""99-my-name-is-John-Smith-6376827-%^-1-2-767980716"""
>>> re.match('.*?([0-9]+)$', s).group(1)
'767980716'

Alternatively, re.finditer works just as well:

>>> next(re.finditer(r'\d+$', s)).group(0)
'767980716'

Explanation of all regexp components:

• .*? is a non-greedy match and consumes only as much as possible (a greedy match would consume everything except for the last digit).
• [0-9] and \d are two different ways of capturing digits. Note that the latter also matches digits in other writing schemes, like ୪ or ൨.
• Parentheses (()) make the content of the expression a group, which can be retrieved with group(1) (or 2 for the second group, 0 for the whole match).
• + means multiple entries (at least one number at the end).
• $ matches only the end of the input.

Answer 4

I have been playing around with several of these solutions, but many seem to fail if there are no numeric digits at the end of the string. The following code should work.

import re

W = input("Enter a string:")
if re.match('.*?([0-9]+)$', W)== None:
    last_digits = "None"
else:
    last_digits = re.match('.*?([0-9]+)$', W).group(1)
print("Last digits of "+W+" are "+last_digits)

Answer 5

Your Regex should be (\d+)$.

• \d+ is used to match digit (one or more)
• $ is used to match at the end of string.

So, your code should be: -

>>> s = "99-my-name-is-John-Smith-6376827-%^-1-2-767980716"
>>> import re
>>> re.compile(r'(\d+)$').search(s).group(1)
'767980716'

And you don't need to use str function here, as s is already a string.

Answer 6

Save the regular expressions for something that requires more heavy lifting.

>>> def parse_last_digits(line): return line.split('-')[-1]
>>> s = parse_last_digits(r"99-my-name-is-John-Smith-6376827-%^-1-2-767980716")
>>> s
'767980716'