从Python字典

Question

删除值我有一个Python字典是这样的：

{'1' : {'1': {'A' : 34, 'B' : 23, 'C' : nan, 'D': inf, ...} ....} ....} 

对于每一个“信”键，我不得不计算出什么，但我得到的数值像INF或NaN，我需要将它们删除。我怎么能这样做？

我的第一次尝试是“腰斩”这样的值，即，只返回0和1000之间的值，但我这样做的时候，我得到空值的字典：

{'1' : {'1': {'A' : 34, 'B' : 23, 'C' : {}, 'D': {}, ...} ....} ....} 

也许是有更好的解决方案，请帮助!!!!

这是我的代码部分，（Q和（L）是有信息，我需要计算其他字典）：

for e in L.keys(): 
    dR[e] = {} 
    for i in L[e].keys(): 
    dR[e][i] = {} 
    for l, ivalue in L[e][i].iteritems(): 
    for j in Q[e].keys(): 
     dR[e][i][j] = {} 
     for q, jvalue in Q[e][j].iteritems(): 
     deltaR = DeltaR(ivalue, jvalue) #this is a function that I create previously 
     if (0 < deltaR < 100): 
      dR[e][i][j] = deltaR 

Answer 1

我走在这里瞎猜，但你可以可能以几种不同的方式做到这一点。一种方法是计算该值，然后决定是否在将其粘贴到字典之前确实想保留它。

d = {} 
for letter in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ': 
    # I don't actually know how you're calculating values 
    # and it kind of doesn't matter 
    value = calculate(letter) 
    if value in (inf, nan): 
     continue 
    d[letter] = value 

我简化字典只关注数据中实际使用字母作为关键字的部分，因为您没有真正给出任何上下文。话虽如此，我可能会采取第一个建议，除非有理由不这样做。

for e in L.keys(): 
    dR[e] = {} 
    for i in L[e].keys(): 
     dR[e][i] = {} 
     for l, ivalue in L[e][i].iteritems(): 
      for j in Q[e].keys(): 
       #dR[e][i][j] = {} # What's up with this? If you don't want an empty dict, 
           # just don't create one. 
       for q, jvalue in Q[e][j].iteritems(): 
        deltaR = DeltaR(ivalue, jvalue) #this is a function that I create previously 
        if (0 < deltaR < 100): 
         dR[e][i][j] = deltaR 
       if dR[e][i][j] in (nan, inf): 
        del dR[e][i][j] 

Answer 2

您应该可以使用del语句来删除字典项目。例如：

del dct['1']['1']['C']