替换烧瓶中字符串列表中的子字符串

Question

我正在使用烧瓶和 pymongo 开展一个项目，并且我有一个用户列表，其中用户实例如下：

user = {"Email":"user@gmail.com" , "Comments":["good" , "not very good " , "hated it "]}

我正在尝试遍历我的用户集合中每个用户的 cmets，如果我在任何评论中找到 string "good"，我想用 "bad" 替换它。使用我下面的代码，每次都会替换字符串，但没有保存在我的 用户集合。

user_list = users.find()
for usr in user_list:
    for comment in usr['Comments']:
        if "good" in comment:
            print("old comment here")
            print(comment)
            comment=comment.replace("good" ,"bad") #does not save the edited comment in the collection !
            print(comment) # the new comment is printed

感谢您对这项简单任务的帮助。 提前谢谢你。

Answer 1

如果您想保留当前的代码结构，您将必须跟踪您在 user_list 中的位置以及注释。然后你可以用新的评论来改变实际的评论。一种方法是使用enumerate

user_list = [{"Email":"user@gmail.com" , "Comments":["good" , "not very good " , "hated it "]}]
for idxu, usr in enumerate(user_list):
    for idxc, comment in enumerate(usr['Comments']):
        if "good" in comment:
            print("old comment here")
            print(comment)
            user_list[idxu]['Comments'][idxc] = comment.replace("good" ,"bad") #does not save the edited comment in the collection !
            print(comment) # the new comment is printed

print(user_list)

>>> [{'Email': 'user@gmail.com', 'Comments': ['bad', 'not very bad ', 'hated it ']}]

如果您想将更改存储在 mongodb 中，您当然必须将更改保存到用户对象。

Answer 2

您只需要替换用户 cmets，这在您的代码中没有完成。

for usr in user_list:
    usr["Comments"] = [i.replace("good", "bad") for i in usr["Comments"]]

例如。

user = {"Email":"user@gmail.com" , "Comments":["good" , "not very good " , "hated it "]}

user_list = [user]
print (user_list)

for usr in user_list:
    usr["Comments"] = [i.replace("good", "bad") for i in usr["Comments"]]

print (user_list)

输出：

[{'Email': 'user@gmail.com', 'Comments': ['good', 'not very good ', 'hated it ']}]
[{'Email': 'user@gmail.com', 'Comments': ['bad', 'not very bad ', 'hated it ']}]