我如何循环遍历字典和集合以获得我想要的值?

Question

我有一个嵌套字典的代码，我想访问"助手"值，并将其追加。我怎么做呢?

gameData = {
"metadata": {
"dataVersion": "2",
"matchId": "NA1_4263873346",
"participants": [
"Sw_wTB5fzxXvyXeCovgcGhKNw4hLKzgcEvWFKzMqZWtfiJ7HtbxYOK6Nb7nBU5SR-B3bNt4Ay9bvjQ",
"-t2_OfuyZFaCdZJ1lvbbfRFgYS1FWZcGhIsqj-8m-SS9UZ9wFyYeWBiGkcMgNEl_geH5CF9tX4SAzQ",
"A-n0X4QWr8Jr0PISogZK3VpnIqqVbm87jchMYpTrUrhiSfeoxVCl8ImnJxaE_lg9pIAdxNgaFpkT7g"
]
},
"info": {
"gameVersion": "12.6.431.7988",
"mapId": 11,
"participants": [
{
"assists": 9,
"deaths": 5,
"kills": 1
},
{
"assists": 1,
"deaths": 3,
"kills": 1
},
{
"assists": 3,
"deaths": 5,
"kills": 6
} 
]
}

我使用这个来循环遍历它们，但是它返回错误"TypeError:列表索引必须是整数或切片，而不是字符串"

participants = []
for row in gameData['metadata']['participants']:
participants_row = {}
participants_row['assists'] = gameData['info']['participants']['assists']
participants.append(participants_row)

谁能帮助我了解如何循环通过它来获得所需的值?

Answer 1

您在访问dict部分时出现了几个错误。

我想你是这个意思:

# gameData = {"metadata": { ...
participants = []
for row in gameData['info']['participants']:
participants_row = {}
participants_row['assists'] = row['assists']
participants.append(participants_row)
print(participants)

您的原始:for row in gameData['metadata']['participants']:在错误的participants列表上迭代。你的意思是:for row in gameData['info']['participants']:

Answer 2

participants_row['assists'] = match_detail['info']['participants']['assists']

我假设是这行代码导致了错误。要调试它，请将其分解为更小的部分:

info = match_detail['info']
participants = info['participants']
assists = participants['assists']

如果这样做，您将看到第三行导致错误。所以添加

print(participants)

现在我们看到participants是一个列表，但是你把它当作字典来使用。

我想你想从每个participant中得到assists。一种方法是使用列表推导式:

assists = [p['assists'] for p in participants]

注:

python团队正在改进错误消息，以便消息指向导致此类错误的特定索引。我不知道它会在哪个版本发布，但我很期待它，因为这种嵌套索引非常常见。