python - 不明白，什么意思：TypeError: can only concatenate str (not "list") to str

Question

在我开始描述问题之前，我需要说，英语不是我的母语，所以，不幸的是，我可能会犯很多错误。感谢您的理解！

favourite_places = {
    'Paris':['Jake','Carl'],
    'London':'Jake',
    'Moscow':'Fred',
 }

for username,user_info in favourite_places.items():
    
print('======================')
    
print('Place: ' + username)
    
print('Who likes it: ' + user_info)

错误：

Type of error: TypeError: can only concatenate str (not "list") to str

我现在真的不知道如何解决它。当我清除['Carl']时，程序开始工作，但我需要['Carl']. 请帮忙

标签： pythontypeerror

Answer 1

Join your list items to make a string:

favourite_places = {
    'Paris':['Jake','Carl'],
    'London':['Jake'],
    'Moscow':['Fred']
 }

for username,user_info in favourite_places.items():
    print('======================')
    print('Place: ' + username)
    print('Who likes it: ' + ', '.join(user_info))