Python 中的 KeyError，即使密钥存在

Question

I have been scratching my head on this for a few days now and cannot seem to find a solution that works online for my problem. I am trying to access data on zendesk and go through the pagination. For some reason, I am getting a KeyError, even though I can see that the key does exist. Here is my code:

data_users2 = [[]]
while url_users:
    users_pagination = requests.get(url_users,auth=(user, pwd))

    data_user_page = json.loads(users_pagination.text)

    print (data_user_page.keys())

    for user in data_user_page['users']:
        data_users2.append(user)
    url = data_user_page['next_page']

Here is the output:

dict_keys(['users', 'next_page', 'previous_page', 'count'])
dict_keys(['error'])
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-22-fab95d95ddeb> in <module>
      6     data_user_page = json.loads(users_pagination.text)
      7     print (data_user_page.keys())
----> 8     for user in data_user_page["users"]:
      9         data_users2.append(user)
     10     url = data_user_page["next_page"]

KeyError: 'users' 

As you can see, users does exist. same thing happens if I try to print the next_page, I get a KeyError for next_page.

Any help would be appreciated ! Thanks!

Answer 1

Your code is failing in its second iteration of the loop, in that moment your keys in data_user_page are just "error" as you can see in the output you have pasted

dict_keys(['users', 'next_page', 'previous_page', 'count']) <----- FIRST ITERATION
dict_keys(['error']) <---- SECOND ITERATION, THEREFORE, YOUR KEY DOES NOT EXISTS
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-22-fab95d95ddeb> in <module>
      6     data_user_page = json.loads(users_pagination.text)
      7     print (data_user_page.keys())
----> 8     for user in data_user_page["users"]:
      9         data_users2.append(user)
     10     url = data_user_page["next_page"]

KeyError: 'users' 

EDIT: This could be due to the fact that you are saving the next url in a variable called url not url_users