優化的Python雙人間循環

Question

下面是我的Python代碼

myList = ['A','B','C','D','E',...] #all elements is string 
myDict = [D1,D2] # let consider 2 dict 
# D1 = {'A':0.1,'B':0.5,'C':0.01,...}  
# D2 = {'A':0.4,'B':0.11,'C':0.21,...} 

myNewDict = {} 
for words in myList: 
    NewList = [] 
    for dicts in myDict: 
      tmps = dicts[words] 
      NewList.append(tmps) 
    myNewDict[words] = (min(NewList), max(NewList)) 

我使用Python 3.4 64位，所以我想通過使用python內置對如何提高代碼的性能提出了一些建議

在功能或任何更好的方式來提高計算時間。在此衷心感謝您的建議和想法。由於

Answer 1

看起來像一個整潔的練習，我終於可以用tee，所以我做了這個：

from itertools import tee 
words = ['A','B','C'] 
dicts = [{'A': 0.1, 'B': 0.5, 'C': 0.01}, 
     {'A': 0.4, 'B': 0.11, 'C': 0.21}] 
newdict = {word: (min(minfeed), max(maxfeed)) 
      for word in words 
      for minfeed, maxfeed in [tee(d[word] for d in dicts)]} 

輸出：

{'B': (0.11, 0.5), 'C': (0.01, 0.21), 'A': (0.1, 0.4)} 

編輯：我很好奇，並嘗試了一些更多的版本，做了大量隨機數據，10萬字和100個詞典的高速測試。結果第一：

5.418 seconds Chin 
4.364 seconds Stefan 
3.460 seconds Stefan2 
3.471 seconds Stefan3 

代碼：

from itertools import tee 
def Stefan(words, dicts): 
    return {word: (min(minfeed), max(maxfeed)) 
      for word in words 
      for minfeed, maxfeed in [tee(d[word] for d in dicts)]} 

def Stefan2(words, dicts): 
    out = {} 
    for word in words: 
     values = [d[word] for d in dicts] 
     out[word] = min(values), max(values) 
    return out 

def Stefan3(words, dicts): 
    return {word: (min(values), max(values)) 
      for word in words 
      for values in [[d[word] for d in dicts]]} 

def Chin(myList, myDict): 
    myNewDict = {} 
    for words in myList: 
     NewList = [] 
     for dicts in myDict: 
       tmps = dicts[words] 
       NewList.append(tmps) 
     myNewDict[words] = (min(NewList), max(NewList)) 
    return myNewDict 

from random import sample, randrange, random 
from string import ascii_letters 
from time import time 

WORDS = 100000 
DICTS = 100 

def random_word(): 
    ''.join(sample(ascii_letters, randrange(2, 10))) 
words = [random_word() for _ in range(WORDS)] 
dicts = [{w: random() for w in words} for _ in range(DICTS)] 

prev = None 
for func in Chin, Stefan, Stefan2, Stefan3: 
    t0 = time() 
    result = func(words, dicts) 
    print('%6.3f seconds' % (time() - t0), func.__name__) 
    if prev and result != prev: 
     print('fail') 
    prev = result