Question

我想从现有词典列表中选择一些键，并通过查找另一张地图来添加其他键。

主要列表如下

result=[{'key1':123,'key2':'prod','key3':'abc','key4':'cde'},{'key1':123,'key2':'prod','key3':'def','key4':'qrs'},{'key1':321,'key2':'sale','key3':'dssd','key4':'cfde'}]

新列表中需要的密钥如下，key5和key6是需要添加的新密钥

wantedkeys=['key1','key3','key5','key6']

字典用于添加新的键值

keyMap={(123, 'key5'): 'abc', (123, 'key6'): 'pqr'}

我可以使用以下语法选择key1和key3来获取输出。

new_list = [{ key: record[key]  for key in wantedkeys } for record in result if record['key2']=='prod']

但是在扩展它的同时还添加了其他键时，出现语法错误。

new_list = [{ key : keyMap[record['key1'],key] if key in ['key5','key6'] else  key: record[key]  for key in wantedkeys } for record in result if record['key2']=='Prod']

我知道可以通过遍历列表来完成此操作，但是由于我的列表将有几百万条记录，因此还有更多的Python方式可以实现更好的性能吗？任何帮助将不胜感激

更新：获得了解决方案。希望这会有所帮助

new_list = [dict({ key: record[key]  for key in ['key1','key3']},key5=keyMap[record['key1'],'key5'],key6=keyMap[record['key1'],'key6']) for record in result if record['key2']=='prod']

Answer 1

得到解决方案。希望这会有所帮助

new_list = [dict({ key: record[key]  for key in ['key1','key3']},key5=keyMap[record['key1'],'key5'],key6=keyMap[record['key1'],'key6']) for record in result if record['key2']=='prod']

从词典列表中选择一些词典关键字，同时还添加新关键字

1 个答案: