如何正确转义单引号和双引号 [英] How to properly escape single and double quotes
问题描述
我有一个lxml etree HTMLParser对象，我正在尝试使用它建立xpath来断言xpath，xpath的属性和该标记的文本.当标签的文本具有单引号(')或双引号()时，我遇到了一个问题，我用尽了所有选项.
I have a lxml etree HTMLParser object that I'm trying to build xpaths with to assert xpaths, attributes of the xpath and text of that tag. I ran into a problem when the text of the tag has either single-quotes(') or double-quotes(") and I've exhausted all my options.
这是我创建的示例对象
parser = etree.HTMLParser()
tree = etree.parse(StringIO(<html><body><p align="center">Here is my 'test' "string"</p></body></html>), parser)
这是代码段，然后是读入的变量的不同变体
Here is the snippet of code and then different variations of the variable being read in
def getXpath(self)
xpath += 'starts-with(., \'' + self.text + '\') and '
xpath += ('count(@*)=' + str(attrsCount) if self.exactMatch else "1=1") + ']'
self.text基本上是标记的预期文本，在这种情况下:这是我的测试"字符串"
self.text is basically the expected text of the tag, in this case: Here is my 'test' "string"
当我尝试使用HTMLParser对象的xpath方法时，这将失败
this fails when i try to use the xpath method of the HTMLParser object
tree.xpath(self.getXpath())
原因是因为它获取的xpath是这个'/html/body/p [starts-with(.，'这是我的'test'字符串"')和1 = 1]'
Reason is because the xpath that it gets is this '/html/body/p[starts-with(.,'Here is my 'test' "string"') and 1=1]'
如何正确地将self.text变量中的单引号和双引号转义?我试过三重引号，将self.text包裹在repr()中，或者做一个re.sub或string.replace，以'和'的\和'来转义
How can I properly escape the single and double quotes from the self.text variable? I've tried triple quoting, wrapping self.text in repr(), or doing a re.sub or string.replace escaping ' and " with \' and \"
推荐答案
根据我们在Wikipedia中看到的 和 w3学校，则您不应具有'和"在节点内容中，即使仅<和&被认为是严格非法的.应将它们替换为相应的预定义实体引用"，分别为'和".
According to what we can see in Wikipedia and w3 school, you should not have ' and " in nodes content, even if only < and & are said to be stricly illegal. They should be replaced by corresponding "predefined entity references", that are ' and ".
顺便说一句，我使用的Python解析器将透明地处理此问题:编写时将它们替换；阅读时，它们会被转换.
By the way, the Python parsers I use will take care of this transparently: when writing, they are replaced; when reading, they are converted.
重新阅读您的答案后，我用'测试了一些东西，以此类推，在Python解释器中进行了测试.它将为您摆脱一切！
After a second reading of your answer, I tested some stuff with the ' and so on in Python interpreter. And it will escape everything for you!
>>> 'text {0}'.format('blabla "some" bla')
'text blabla "some" bla'
>>> 'ntsnts {0}'.format("ontsi'tns")
"ntsnts ontsi'tns"
>>> 'ntsnts {0}'.format("ontsi'tn' \"ntsis")
'ntsnts ontsi\'tn\' "ntsis'
因此我们可以看到Python正确地进行了转义.然后可以复制粘贴收到的错误消息(如果有)吗?
So we can see that Python escapes things correctly. Could you then copy-paste the error message you get (if any)?
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