Question

I have a list of objects (strings in this example) which I want to categorize according to a certain characteristic returned by a function.

例如,审议以下清单:

[ sky ,  ocean ,  grass ,  tomato ,  leaf ]

http://www.ohchr.org。我现在想将清单变成一个字典或清单,根据这些物品的颜色/按功能退还的价值分类。可能的结果是:

{ 
     blue : [ sky ,  ocean ],
     green : [ grass ,  leaf ],
     red : [ tomato ]
}

我并不关心钥匙本身,只是这些物品按顺序分类,因此,nes名单也会被罚款。只是试图以onic的方式做到这一点:

Answer 1

我认为,我这样谈谈这个问题:

from collections import defaultdict

D = defaultdict(list)

a = [ sky ,  ocean ,  grass ,  tomato ,  leaf ]

for item in a:
  D[color(item)].append(item)

这使你有一个名单的字典,由色人标明,其中含有这一类物品。

Answer 2

a = [ sky ,  ocean ,  grass ,  tomato ,  leaf ]

sa = {}
for x in a:
  key = color(x)
  if key in sa:
    sa[key].append(x)
  else:
    sa[key] = [x]

不能确定这种疾病是多么高尚的,而是十分清楚。在足够晚的波什里,你可以使用一种缺省词典,使 lo体更清洁。

Answer 3

提议稍微修改解决办法:

www.un.org/Depts/DGACM/index_spanish.htm

a = [ sky ,  ocean ,  grass ,  tomato ,  leaf ]

def color(x):
    # dummy hash function for demo
    return len(x)

color_map = {}

for x in a:
    key = color(x)
    color_map.setdefault(key,[]).append(x)

print color_map

以上编码实例:

{3: [ sky ], 4: [ leaf ], 5: [ ocean ,  grass ], 6: [ tomato ]}

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