python - 遍历列表的字典 + 将相同键的值相加

Question

我有这样的数据结构：

[
    { "key" : { "subkey" : "red", "value" : 1 }  },
    { "key" : { "subkey" : "red", "value" : 2 }  },
    { "key" : { "subkey" : "blue", "value" : 1 }  },
    { "key" : { "subkey" : "yellow", "value" : 3 }  },
    { "key" : { "subkey" : "blue", "value" : 5 }  },
    { "key" : { "subkey" : "blue", "value" : 8 }  },
    { "key" : { "subkey" : "red", "value" : 2 }  },
    { "key" : { "subkey" : "red", "value" : 3 }  },
    { "key" : { "subkey" : "red", "value" : 6 }  },
]

这个想法是我想遍历它，当至少 2"subkeys"个相同时，触发some_event()，这会将这些连续对象的值相加，直到它"subkey"再次遇到不同的对象。

例如，第一个和第二个 dicts 应该在添加some_event()值的情况下触发2+1。some_event()然后第三行（蓝色）和第四行（黄色）没有任何反应，第五和第六行（蓝色）用 values5+8等触发。

谢谢！

Answer 1

from itertools import groupby

L = [
    { "key" : { "subkey" : "red", "value" : 1 }  },
    { "key" : { "subkey" : "red", "value" : 2 }  },
    { "key" : { "subkey" : "blue", "value" : 1 }  },
    { "key" : { "subkey" : "yellow", "value" : 3 }  },
    { "key" : { "subkey" : "blue", "value" : 5 }  },
    { "key" : { "subkey" : "blue", "value" : 8 }  },
    { "key" : { "subkey" : "red", "value" : 2 }  },
    { "key" : { "subkey" : "red", "value" : 3 }  },
    { "key" : { "subkey" : "red", "value" : 6 }  },
]


def some_event(*args):
    print args, sum(args)


for k, g in groupby(L, key=lambda x:x["key"]["subkey"]):
    g = list(g)
    if len(g) > 1:
        some_event(*(i["key"]["value"] for i in g))