我有一個 json 格式列表，每個列表中有一些字典，它看起來像下面這樣：[{"id":13, "name":"Albert", "venue":{"id":123, "town":"Birmingham"}, "month":"February"},{"id":17, "name":"Alfred", "venue":{"id":456, "town":"London"}, "month":"February"},{"id":20, "name":"David", "venue":{"id":14, "town":"Southampton"}, "month":"June"},{"id":17, "name":"Mary", "venue":{"id":56, "town":"London"}, "month":"December"}]列表中的條目數量最多可達 100 個。我計劃為每個條目顯示“名稱”，一次一個結果，對于那些以倫敦為城鎮的條目。其余的對我沒用。我是 python 的初學者，所以我很感激有關如何有效地進行此操作的建議。我最初認為最好刪除所有沒有倫敦的條目，然后我可以一一瀏覽它們。我還想知道不過濾而是循環遍歷整個 json 并選擇將城鎮作為倫敦的條目的名稱是否會更快。
2 回答
人到中年有點甜
TA貢獻1895條經驗 獲得超7個贊
您可以使用filter：
data = [{"id":13, "name":"Albert", "venue":{"id":123, "town":"Birmingham"}, "month":"February"},
{"id":17, "name":"Alfred", "venue":{"id":456, "town":"London"}, "month":"February"},
{"id":20, "name":"David", "venue":{"id":14, "town":"Southampton"}, "month":"June"},
{"id":17, "name":"Mary", "venue":{"id":56, "town":"London"}, "month":"December"}]
london_dicts = filter(lambda d: d['venue']['town'] == 'London', data)
for d in london_dicts:
print(d)
這是盡可能有效的，因為：
循環是用 C 編寫的（在 CPython 的情況下）
filter 返回一個迭代器（在Python 3中），這意味著根據需要將結果一一加載到內存中
一只甜甜圈
TA貢獻1836條經驗 獲得超5個贊
一種方法是使用列表理解：
>>> data = [{"id":13, "name":"Albert", "venue":{"id":123, "town":"Birmingham"}, "month":"February"},
{"id":17, "name":"Alfred", "venue":{"id":456, "town":"London"}, "month":"February"},
{"id":20, "name":"David", "venue":{"id":14, "town":"Southampton"}, "month":"June"},
{"id":17, "name":"Mary", "venue":{"id":56, "town":"London"}, "month":"December"}]
>>> [d for d in data if d['venue']['town'] == 'London']
[{'id': 17,
'name': 'Alfred',
'venue': {'id': 456, 'town': 'London'},
'month': 'February'},
{'id': 17,
'name': 'Mary',
'venue': {'id': 56, 'town': 'London'},
'month': 'December'}]
添加回答
舉報
0/150
提交
取消