在Python 3中构建嵌套字典时出现问题
我想基于文本文件构建一个嵌套字典。例如(text.txt) 理想情况下,我希望得到以下嵌套字典在Python 3中构建嵌套字典时出现问题,python,Python,我想基于文本文件构建一个嵌套字典。例如(text.txt) 理想情况下,我希望得到以下嵌套字典 ... {'hostA': {'FQHN': 'hostA.testing.com', 'IP': '192.168.1.101'}, 'hostB': {'FQHN': 'hostB.testing.com', 'IP': '192.168.1.102'}} ... 因此,我编写了以下Python代码: myinnerdict={} myouterdict={} def main():
...
{'hostA': {'FQHN': 'hostA.testing.com', 'IP': '192.168.1.101'}, 'hostB': {'FQHN': 'hostB.testing.com', 'IP': '192.168.1.102'}}
...
因此,我编写了以下Python代码:
myinnerdict={}
myouterdict={}
def main():
my_fh = open('text.txt', 'r')
for line in my_fh:
newline = line.strip().split() # get ride of the '\n' and make it a inner list .
#print(newline)
myinnerdict['FQHN']=newline[1]
myinnerdict['IP']=newline[2]
#print(myinnerdict)
#print(newline[0])
myouterdict[newline[0]]=myinnerdict
print(myouterdict)
if __name__ == "__main__":
main()
...
然而,超出我的理解,当我运行它时,我得到了以下结果:
...
{'hostA': {'FQHN': 'hostB.testing.com', 'IP': '192.168.1.102'}, 'hostB': {'FQHN': 'hostB.testing.com', 'IP': '192.168.1.102'}}
...
这不是我想要的,我不知道我错过了什么,请帮忙。发生这种情况是因为您正在为
innerdict
重用相同的dict对象。您需要在循环中创建一个新的dict对象:
myouterdict={}
def main():
my_fh = open('text.txt', 'r')
for line in my_fh:
myinnerdict={}
newline = line.strip().split() # get ride of the '\n' and make it a inner list .
#print(newline)
myinnerdict['FQHN']=newline[1]
myinnerdict['IP']=newline[2]
#print(myinnerdict)
#print(newline[0])
myouterdict[newline[0]]=myinnerdict
print(myouterdict)
if __name__ == "__main__":
main()
问题是您正在为字典重用相同的变量。由于
myoutedict
存储的是对变量myinnerdict
的引用,而不是实际数据,因此两者是相同的。例如,尝试以下方法:
>>> a = {}
>>> b = {"my a variable": a}
>>> b
{'my a variable': {}}
>>> a["asdf"] = 3
>>> b
{'my a variable': {'asdf': 3}}
如您所见,b
存储的是a
的引用,而不是a
的空dict数据。您需要做的是结束它(请注意,.copy()
不会复制dict的内容,但会使新的引用读得更多):
无论如何,您也可以立即分配新创建的dict对象,而不是使用变量:
mydict = {}
def main():
my_fh = open('test.txt', 'r')
for line in my_fh:
newline = line.strip().split()
mydict[newline[0]] = {"FQHN": newline[1], "IP": newline[2]}
print(mydict)
my_fh.close()
if __name__ == "__main__":
main()
myinnerdict = {}
myouterdict = {}
def main():
my_fh = open('text.txt', 'r')
for line in my_fh:
newline = line.strip().split()
myinnerdict['FQHN'] = newline[1]
myinnerdict['IP'] = newline[2]
# Note this copy here
myouterdict[newline[0]] = myinnerdict.copy()
print(myouterdict)
# Remember to close the file!
my_fh.close()
if __name__ == "__main__":
main()
mydict = {}
def main():
my_fh = open('test.txt', 'r')
for line in my_fh:
newline = line.strip().split()
mydict[newline[0]] = {"FQHN": newline[1], "IP": newline[2]}
print(mydict)
my_fh.close()
if __name__ == "__main__":
main()