35. firstDigit

Task

Find the leftmost digit that occurs in a given string.

Example

• For inputString = "var_1__Int", the output should be
  firstDigit(inputString) = '1';

• For inputString = "q2q-q", the output should be
  firstDigit(inputString) = '2';

• For inputString = "0ss", the output should be
  firstDigit(inputString) = '0'.

Input/Output

• [execution time limit]
  4 seconds (py3)

• [input] string inputString
  A string containing at least one digit.
  Guaranteed constraints: 3 ≤ inputString.length ≤ 10.

• [output] char

My Solution

def firstDigit(inputString):
    for letter in inputString:
        if letter.isdigit():
            return letter
    return