假设您说列表"的意思是数组"，则可以

Assuming you mean "list" where you say "array", you can do

if item in my_list:
    # whatever

这适用于所有集合，而不仅限于列表.对于字典，它将检查字典中是否存在给定的键.

This works for any collection, not just for lists. For dictionaries, it checks whether the given key is present in the dictionary.