Question

我正在检查字典中的密钥，如果它包含space删除它。

def query_combination(sentence,mydict):
    for key in mydict.keys():
        if key == 'key':
            pass
        else:
            print 'key is : ',key
            if " " in key:                
                temp = key
                key = key.replace(' ',"")
                print 'new key : ',key                    
                sentence = sentence.replace(temp ,key)
                print 'new sentence : ',sentence
    print mydict
mydict = {'films': {'match': ['Space', 'Movie', 'six', 'two', 'one']}, u'Popeye Doyle': {'score': 100, 'match': [u'People', 'heaven', 'released']}}
sentence ='What films featured the character Popeye Doyle'
combination = query_combination(sentence,mydict)

我无法将新密钥值动态更改为mydict。任何建议都很明显

Answer 1

如果从字典中获取字符串，然后更改它并创建一个新字符串，字典将不会知道它;您可以在字典中添加新条目并删除旧条目：

        if " " in key:                
            newkey = key.replace(' ',"")
            mydict[newkey] = mydict[key]
            del mydict[key]

            print 'new key : ', newkey

Answer 2

你可以试试这个

def query_combination(sentence,mydict):
    for key in mydict.iterkeys():
        if " " in key:                
            temp = key
            mydict[key.replace(" ","")] = mydict[key] # create new key
            del mydict[key] # delete old key
            sentence = sentence.replace(temp ,key)

一行中的另一个解决方案是

mydict[key.replace(" ","")] = mydict.pop(key)

Answer 3

key = key.replace(' ',"")不影响字典中的实际密钥，它正在更改该密钥的副本。您需要使用新密钥将值添加到字典中并删除旧密钥。这是一种方法：

def query_combination(sentence, mydict):
    for old_key, new_key in [(key, key.replace(' ', '')) for key in mydict if ' ' in key]:
        mydict[new_key] = mydict.pop(old_key)
        sentence = sentence.replace(old_key, new_key)

但请注意，您要替换字符串sentence中的密钥，但sentence是函数query_combination()的本地密钥，因此外部范围sentence不受影响更换。我不确定这是否是您希望代码执行的操作，但如果是，您只需从函数中返回修订后的sentence，或将其作为项目包含在字典中。

鉴于您的函数实际上没有更新sentence，您可以将整个函数简化为单纯的字典理解：

>>> mydict = {'films': {'match': ['Space', 'Movie', 'six', 'two', 'one']}, u'Popeye Doyle': {'score': 100, 'match': [u'People', 'heaven', 'released']}}
>>> mydict = {key.replace(' ', '') : value for key, value in mydict.items()}
>>> mydict
{'films': {'match': ['Space', 'Movie', 'six', 'two', 'one']}, u'PopeyeDoyle': {'score': 100, 'match': [u'People', 'heaven', 'released']}}

动态更改字典中的键值

3 个答案: