There is a method called isdigit() in String class that returns true if all characters in the string are digits and there is at least one character, false otherwise. You can call it as follows −
Example
print("12345".isdigit())
print("12345a".isdigit())Output
True False
You can also use regexes for the same result. For matching only digits, we can call the re.match(regex, string) using the regex: "^[0-9]+$".
example
import re
print(bool(re.match('^[0-9]+$', '123abc')))
print (bool(re.match('^[0-9]+$', '123')))Output
False True
re.match returns an object, to check if it exists or not, we need to convert it to a boolean using bool().