什么是测试输入是格式良好的数字的最pythonic方式

import re

def is_valid_number(input_str):
    try:
        float(input_str)
        return True
    except ValueError:
        return False

def is_valid_number_regex(input_str):
    pattern = r'^[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?$'
    return bool(re.match(pattern, input_str))

input_str = "123.45"

if is_valid_number(input_str):
    print("The input is a valid number")
else:
    print("The input is not a valid number")

if is_valid_number_regex(input_str):
    print("The input is a valid number using regex")
else:
    print("The input is not a valid number using regex")