python3.x版本下,在用example_dict.keys()或者example_dict.values()取出字典中对应的键值时,取出的值总是会带有前缀。
python2.x版本的不存在这个问题,可以直接使用书中的代码
以下是python3.x版本代码:
def getNumLeafs(myTree): # python3 版本 返回叶子数
numLeafs = 0
secondDict = list(myTree.values())
for key in range(len(secondDict[0])):
if type(secondDict[0][key]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
numLeafs += getNumLeafs(secondDict[0][key])
else: numLeafs +=1
return numLeafs
def getTreeDepth(myTree): # python3 版本 返回树的深度,即多少层
maxDepth = 0
secondDict = list(myTree.values()) # 去掉dict_values类名
for key in range(len(secondDict[0])):
if type(secondDict[0][key]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
thisDepth = 1 + getTreeDepth(secondDict[0][key])
else: thisDepth = 1
if thisDepth > maxDepth: maxDepth = thisDepth
return maxDepth
对不起,各位看官,上面的代码有点投机取巧了
由于字典的key正好是0,1
,所以可以secondDict[0][key]
这样索引
下面我将进行修改,使得代码普适性更好
def getNumLeafs(myTree): # python3 版本 返回叶子数
numLeafs = 0
secondDict = list(myTree.values())[0]
xinkeys=list(secondDict.keys())
for key in range(len(secondDict)):
if type(secondDict[xinkeys[key]]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
numLeafs += getNumLeafs(secondDict[xinkeys[key]])
else: numLeafs +=1
return numLeafs
def getTreeDepth(myTree): # python3 版本 返回树的深度,即多少层
maxDepth = 0
secondDict = list(myTree.values())[0] # 去掉dict_values类名
xinkeys=list(secondDict.keys())
for key in range(len(secondDict)):
if type(secondDict[xinkeys[key]]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
thisDepth = 1 + getTreeDepth(secondDict[xinkeys[key]])
else: thisDepth = 1
if thisDepth > maxDepth: maxDepth = thisDepth
return maxDepth