split string on any special character using python-CodePudding

currently I can have many dynamic separators in string like

new_123_12313131
new$123$12313131
new#123#12313131

etc etc . I just want to check if there is a special character in string then just get value after last separator like in this example just want 12313131

CodePudding user response：

This is a good use case for isdigit():

l = [
'new_123_12313131',
'new$123$12313131',
'new#123#12313131',
]

output = []
for s in l:
    temp = ''
    for char in s:
        if char.isdigit():
            temp  = char
    output.append(temp)        

print(output)

Result: ['12312313131', '12312313131', '12312313131']

CodePudding user response：

Assuming you define 'special character' as anything thats not alphanumeric, you can use the str.isalnum() function to determine the first special character and leverage it something like this:

def split_non_special(input) -> str:
    """
    Find first special character starting from the end and get the last piece
    """
    for i in reversed(input):
        if not i.isalnum():
            return input.split(i)[-1] # return as soon as a separator is found
    return '' # no separator found

# inputs = ['new_123_12313131', 'new$123$12313131', 'new#123#12313131', 'eefwfwrfwfwf3243']
# outputs = [split_non_special(input) for input in inputs]
# ['12313131', '12313131', '12313131', ''] # outputs

CodePudding user response：

just get value after last separator

the more obvious way is using re.findall:

from re import findall

findall(r'\d $',text)  # ['12313131']

CodePudding user response：

Python supplies what seems to be what you consider "special" characters using the string library as string.punctuation. Which are these characters:

!"#$%&'()* ,-./:;<=>?@[\]^_`{|}~

Using that in conjunction with the re module you can do this:

from string import punctuation
import re

re.split(f"[{punctuation}]", my_string)

my_string being the string you want to split.

Results for your examples

['new', '123', '12313131']

To get just digits you can use:

re.split("\d", my_string)

Results:

['123', '12313131']