
Count Digits

You need to count the number of digits in a given string.
Input: String.
Output: Integer.
Examples:
assert count_digits("hi") == 0 assert count_digits("who is 1st here") == 1 assert count_digits("my numbers is 2") == 1 assert ( count_digits( "This picture is an oil on canvas painting by Danish artist Anna Petersen between 1845 and 1910 year" ) == 8 )