Python，美汤，获取所有类名

Question

给定一个 html 代码让我们说:

 <div class="class1">
    <span class="class2">some text</span>
    <span class="class3">some text</span>
    <span class="class4">some text</span>
    </div>

如何检索所有类名？即:['class1','class2','class3','class4']

我试过:

soup.find_all(class_=True)

但它会检索整个标签，然后我需要对字符串做一些正则表达式

Answer 1

您可以 treat each Tag instance found as a dictionary在检索属性时。请注意，class 属性值将是一个列表，因为class 是一个特殊的"multi-valued" attribute。 :

classes = []
for element in soup.find_all(class_=True):
    classes.extend(element["class"])

或者:

classes = [value
           for element in soup.find_all(class_=True)
           for value in element["class"]]

演示:

from bs4 import BeautifulSoup

data = """
<div class="class1">
<span class="class2">some text</span>
<span class="class3">some text</span>
<span class="class4">some text</span>
</div>
"""

soup = BeautifulSoup(data, "html.parser")

classes = [value
           for element in soup.find_all(class_=True)
           for value in element["class"]]

print(classes)

# Returns
# ['class1', 'class2', 'class3', 'class4']