The label filter and predetermined rules of the Python Bleach library (in-defleanation of tag files and predefined rules in Python Bleach Library))
The Python Bleach library is a library for label filtering and cleaning for HTML input content.It is used to protect applications from potential security threats, such as cross -site script attack (XSS).
When using the BLEACH library, label filters and predetermined rules are very important.The label filter is used to define which HTML tags can be retained, and the predefined rules are a set of default rules for filtering and cleaning HTML content.
First, let's take a look at how to install the BLEACH library.You can use the following command to install it:
pip install bleach
After the installation is completed, we can start using the BLEACH library.The following is an example code that shows how to use label filters and predetermined rules to clean up HTML content:
python
import bleach
html_content = '<p>This is <script>alert("XSS attack!")</script> a sample HTML content.</p>'
Allowed_tags = ['P'] # Only allow the P tag
clean_content = bleach.clean(html_content, tags=allowed_tags)
print(clean_content)
The above code will output the following results:
<p>This is a sample HTML content.</p>
In the above examples, the `Script>` label is filtered and deleted from the HTML content.
In addition to specified the allowable labels, the BLEACH library also provides us with some predetermined rules.These rules can be used by passing the "STRIP" parameter, which defaults to this parameter `true`.
For example, the following example code demonstrates how to use predefined rules to clean up HTML content:
python
import bleach
html_content = '<p>This is <strong>strong</strong> and <em>emphasized</em> text.</p>'
clean_content = bleach.clean(html_content, strip=True)
print(clean_content)
The output result is as follows:
<p>This is <strong>strong</strong> and <em>emphasized</em> text.</p>
The HTML tags and their attributes in the example code are retained.
It should be noted that the label filter and predetermined rules of the BLEACH library are not suitable for the attributes in the filter content.If you want to filter the attribute, you can use the `Attributes` parameter in the` Clean` function provided by Bleach.
To sum up, the Python Bleach library provides label filters and predetermined rules, which can help clean up and protect HTML content to ensure that the application is exempted from potential security threats.Using these functions can effectively prevent security issues such as cross -site script attacks.
