replace替换

a = 'helloworld'


def replace(s, old, new):
    return new.join(s.split(old))


def replace_other(s, number):
    return s.replace(a[number], 'm')


if __name__ == "__main__":
    print(f"输出结果为{replace(a, 'hello', 'world')}")
    print(f"输出结果为{replace_other(a, 0)}")

执行结果