Detecting float or int in a string

[Clunk_Head]

Float will handle exponential notation while yours will not. Up to you if that's a problem. Yours will not handle negative numbers or numbers with an explicit plus sign.

Think I've got it fixed:

def is_number(string):
    if string.isnumeric():
        return True
    if string[0] == '-' or string[0] == '+':
        return is_number(string[1: ])
    if string.count('.') == 1:
        return is_number(string.replace('.', '')
    elif string.count('e') == 1:
        index = string.find('e')
        return is_number(string[ :index]) and is_number(string[index+1: ])
    return False

There's probably another case that I've missed. Please let me know if you see one.