xxxxxxxxxx
<!-- You can put any number you want in maxlength i.e 4 -->
<input type="text" maxlength="4" onkeypress='return event.charCode >= 48 && event.charCode <= 57'/>
xxxxxxxxxx
import re
pattern = r"^\d{10}$"
test_string = "1234567890"
if re.match(pattern, test_string):
print("Match found!")
else:
print("No match found.")