如果是用户输入，则找不到对象

Question

search_type = str(input("Enter search paramiter. (type top for top of all time) (type hot for populour posts in the last 24 hours) (type new for the newest posts): "))

    hot_apex = subred.search_type(limit=num)

我希望 search_type 来自用户输入，这样用户可以写 top 然后搜索 type = top 并更改为

hot_apex = subred.top(limit=num)

但是，我收到此错误消息 'Subreddit' object has no attribute 'search_type' however top is a object of subreddit

Answer 1

只需使用条件语句：

search_type = str(input("Enter search paramiter. (type top for top of all time) (type hot for populour posts in the last 24 hours) (type new for the newest posts): "))

if search_type == "top"
    hot_apex = subred.top(limit=num)
elif search_type == "hot":
    hot_apex = subred.hot(limit=num)
else:
    #return error

Answer 2

search_type是定义为字符串的变量。

subred.search_type 尝试在 subred 对象中查找名为 "search_type" 的属性。它不解析变量 search_type并查找由该变量的值命名的属性。为此，您需要使用 getattr() 函数。

search_type = input("Enter type: ")
try:
    func_to_call = getattr(subred, search_type)
    results = func_to_call(limit=num)
except AttributeError:
    print("Invalid input")
    results = []

或者，您可以使用 if..elif 阶梯，但是如果您有许多可能的有效输入，这很快就会变得很麻烦：

if search_type == "hot":
    results = subred.hot(limit=num)
elif search_type == "top":
    results = subred.top(limit=num)
else:
    print("Invalid input")
    results = []

如果是用户输入，则找不到对象

Object not found if its a user input

python

praw