python - 产生 TypeError 的基本代码

Question

所以，我希望这段代码让用户输入狗狗链地址，然后我得到那个地址的余额。当我执行这个我得到错误：

url = "https://dogechain.info/api/v1/address/balance/"+ a

错误：

TypeError: cannot concatenate 'str' and 'int' objects

代码：

import requests

def main():
    a = input("Address?")
    url = "https://dogechain.info/api/v1/address/balance/"+ a
    response = requests.get(url)
    bal = response.json()[0]["balance"]
    print("Balance:",bal)

main()

Answer 1

url = "https://dogechain.info/api/v1/address/balance/" + str(a)

或者

url = "https://dogechain.info/api/v1/address/balance/{}".format(a)

@Ryan O'Donnell 下面的评论解释了原因，谢谢。