ক্যারেক্টার ক্লাস

import re
​
# A character set containing all vowels
pattern = r"[aeiou]"
​
# Lets check whether a word got a vowel in it or not
if re.search(pattern, "grey"):
   print("The word 'grey' got at least one vowel!")
else:
   print("No vowel found!")    
​
if re.search(pattern, "qwertyuiop"):
   print("The word 'qwertyuiop' got at least one vowel!")
else:
   print("No vowel found!")
​
if re.search(pattern, "rhythm myths"):
   print("The word 'rhythm myths' got at least one vowel!")
else:
   print("No vowel found!")

The word 'grey' got at least one vowel!
The word 'qwertyuiop' got at least one vowel!
No vowel found!

import re
​
pattern = r"[A-Z][A-Z][0-9]"
​
if re.search(pattern, "NS1 is prefix of first name server address."):
   # Found NS1 as match
   print("OK")
​
if re.search(pattern, "You should put a second one with NS2 as prefix."):
   # Found NS2 as match
   print("OK")
​
if re.search(pattern, "I don\'t have any nameserver."):
   print("NS3")
else:
   print("Not OK!")
​
if re.search(pattern, "PY3K"):
   # Found PY3 as match
   print("OK")

OK
OK
Not OK!
OK

import re
​
# Match string that contains NOT ALL Capital letters
pattern = r"[^A-Z]"
​
if re.search(pattern, "a sentence with all lower case letters."):
   print("Match 1")
​
if re.search(pattern, "A sentence with mixed English letters."):
   print("Match 2")
​
if re.search(pattern, "HEADING"):
   # All Capital letters
   # No Match
   print("Match 3")
​
if re.search(pattern, "HEADING WITH ALL CAPITAL LETTERS"):
   # All Capital letters 
   # but "spaces" makes it True to NOT ALL Capital
   print("Match 4")

Match 1
Match 2
Match 4