0210. Is it a number?

Given a string s, write a method (function) that will return true if its a valid single integer or floating number or false if its not.

Valid examples, should return true:

isDigit("3")
isDigit("  3  ")
isDigit("-3.23")

should return false:

isDigit("3-4")
isDigit("  3   5")
isDigit("3 5")
isDigit("zero")

Solution:

def isDigit(string: str) -> bool:
    return string.strip().lstrip("-").replace(".", "").isdigit()