def is_numeric(string):

    try:

        float(string)

        return True

    except ValueError:

        return False

​

# Example usage:

string = "12345"

print(is_numeric(string))  # True

​

string = "12.345"

print(is_numeric(string))  # True

​

string = "abc123"

print(is_numeric(string))  # False