How to get a list of matchable characters from a regex class

Question

Given a regex character class/set, how can i get a list of all matchable characters (in python 3). E.g.:

[\dA-C]

should give

['0','1','2','3','4','5','6','7','8','9','A','B','C']

Answer 1

I think what you are looking for is string.printable which returns all the printable characters in Python. For example:

>>> import string
>>> string.printable
'0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~ \t\n\r\x0b\x0c'

Now to check content satisfied by your regex, you may do:

>>> import re
>>> x = string.printable
>>> pattern = r'[\dA-C]'
>>> print(re.findall(pattern, x))
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C']

string.printable is a combination of digits, letters, punctuation, and whitespace. Also check String Constants for complete list of constants available with string module.

---

In case you need the list of all unicode characters, you may do:

import sys
unicode_list = [chr(i) for i in range(sys.maxunicode)]

Note: It will be a huge list, and console might get stuck for a while to give the result as value of sys.maxunicode is:

>>> sys.maxunicode
1114111

In case you are dealing with some specific unicode formats, refer Unicode Character Ranges for limiting the ranges you are interested in.

Answer 2

import re

x = '123456789ABCDE'
pattern = r'[\dA-C]'
print(re.findall(pattern,x))    
#prints ['1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C']

Is this what you are looking for?

If you don't have x and just want to match ascii characters you can use :

import re
import string

x = string.ascii_uppercase + string.digits
pattern = r'[\dA-C]'
print(re.findall(pattern,x))    

If you want to take inputs for the pattern you can simply just do:

 pattern = input() #with either one from above