python remove letters from string

def nospecial(text):
	import re
	text = re.sub("[^a-zA-Z0-9]+", "",text)
	return text

s = 'abc12321cba'

print(s.replace('a', ''))

string = "abc123"
# Method 1
''.join(char for char in string if char.isdigit())

#Method 2
import re
re.sub("[^0-9]", "", string)

"Str*ing With Chars I! don't want".replace('!','').replace('*','')

s = 'ab12abc34ba'
print(s.replace('ab', ''))