MongoDB/PyMongo:如何在正则表达式搜索中“转义"参数? [英] MongoDB/PyMongo: how to 'escape' parameters in regex search?

问题描述

我正在使用pymongo，并且想要搜索以某些字符序列开头的项目.我可能会这样实现:

I'm using pymongo and want to do a search for items starting with a certain sequence of characters. I might implement that like this:

items = collection.find({ 'key': '/^text/' })

这应该起作用，但是如果text是变量怎么办?我可以做类似的事情:

This should work, but what if text is a variable? I could do something like:

items = collection.find({ 'key': '/^' + variable + '/' })

但是现在，如果variable中的文本包含具有特殊正则表达式含义的任何字符(例如$)，则查询将不再表现出预期的行为. 是否可以进行某种参数绑定?我必须自己清理variable吗?这甚至可靠吗?

But now if the text in variable contains any characters with special regex meaning (such as $), the query no longer behaves as expected. Is there a way to do some sort of parameter binding? Do I have to sanitize variable myself? Is that even reliably possible?

谢谢！

推荐答案

您必须以编程方式组装正则表达式.所以:

You have to assemble the regex programmatically. So either:

import re
regex = re.compile('^' + re.escape(variable))
items = collection.find({ 'key': regex })

OR

items = collection.find({'key': { '$regex': '^' + re.escape(variable) }})

请注意，该代码使用 re.escape 对字符串进行转义，以防万一包含特殊字符.

Note that the code uses re.escape to escape the string in case it contains special characters.

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