如何将字符串中的列表转换为列表 [英] How to convert a list within a string to a list
问题描述
我有一个字典,其中一些值是列表.不幸的是,Python认为它们是字符串.该字典看起来像这样:
I have a dict where some of the values are lists. Unfortunately, Python thinks they are strings. The dict looks like this:
dict = {'key': 'x', 'key1': '[1, 2, 3], ...'}
当我拉 dict ['key1']
并尝试对其执行列表操作时,我得到的回溯说我不能,因为该元素是字符串.没问题,但是将其从字符串转换为列表会分别转换字符串的每个字符.
When I pull dict['key1']
and try to perform list operations on it, I get tracebacks that say I can't because the element is a string. No problem, but converting it from a string to a list converts each character of the string separately.
list = list(dict['key1'])
>>> ['[', '1', ',' ' ', '2', ',', ' ', '3', ']']
如何转换字符串以将其作为列表类型?
how do I convert the string to get this as a list type?
>>> [1, 2, 3]
Python 2.5是必需的.
Python 2.5 is a requirement.
已更新:已更正,使列表成为字符串.更新2:包括用于生成字典的代码.它从XML源创建一个字典.
Updated: corrected to make the list a string. Update 2: includes code used to generate the dict. It creates a dict from an XML source.
class XmlDictConfig(dict):
def __init__(self, parent_element):
if parent_element.items():
self.updateShim(dict(parent_element.items()))
for element in parent_element:
if len(element):
aDict = XmlDictConfig(element)
if element.items():
aDict.updateShim(dict(element.items()))
self.updateShim({element.tag: aDict})
elif element.items():
self.updateShim({element.tag: dict(element.items())})
else:
self.updateShim({element.tag: element.text}) # WAS: _self.updateShim({element.tag: element.text.strip()})_ with strip(), the function will choke on some XML.
def updateShim (self, aDict ):
for key in aDict.keys():
if key in self:
value = self.pop(key)
if type(value) is not list:
listOfDicts = []
listOfDicts.append(value)
listOfDicts.append(aDict[key])
self.update({key: listOfDicts})
else:
value.append(aDict[key])
self.update({key: value})
else:
self.update(aDict)
def flatten_dict(d):
def expand(key, value):
if isinstance(value, dict):
return [ (key + '_' + k, v) for k, v in flatten_dict(value).items() ]
else:
return [ (key, value) ]
items = [ item for k, v in d.items() for item in expand(k, v) ]
return dict(items)
try:
socket.setdefaulttimeout(15)
f = urllib2.urlopen(xmlAddress)
data = str(f.read())
f.close()
xmlRawData = re.sub(' xmlns="[^"]+"', '', data, count=1)
root = ElementTree.XML(xmlRawData)
except:
print "Something went very wrong."
xmlDict = XmlDictConfig(root)
flatxmlDict = flatten_dict(xmlDict)
finalDict = {}
for (key, value) in flatxmlDict.items():
finalDict[key] = str(value)
推荐答案
如果您的意思是拥有这样的字典:
If you mean you have a dictionary like this:
dct = {'key': 'x', 'key1': '[1, 2, 3]'}
您可以使用 ast.literal_eval
将列表的字符串表示形式转换为实际列表:
you can use ast.literal_eval
to make make the string representation of a list into an actual list:
>>> from ast import literal_eval
>>> dct = {'key': 'x', 'key1': '[1, 2, 3]'}
>>> dct['key1'] = literal_eval(dct['key1'])
>>> dct
{'key': 'x', 'key1': [1, 2, 3]}
>>> type(dct['key1'])
<class 'list'>
>>>
当然,最好调查一下为什么首先将列表做成字符串,然后改成字符串.
Of course, it would probably be better to investigate why the list is being made into a string in the first place and then fix that instead.
这篇关于如何将字符串中的列表转换为列表的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!