在 BeautifulSoup Find() function 中正确使用变量

Question

How to use variables correctly in BeautifulSoup's.find() function?

Probably a simple solution but the official documentation doesn't cover it and the solution eludes me. Latest Python, stable version and latest BeautifulSoup as of yesterday.

Using the find() function seems to fail when you specify string variables as a parameter.

HTML <h3 id="ourId">Something</h3>

For example:

prodTitle = page.find("h3", {"id": "ourId"}).get_text(strip=True)

That code works.

tag="h3"
attrib="id"
element="ourId"
prodTitle = page.find(tag, {attrib: element}).get_text(strip=True)

The above fails, any usage of a variable within Find() and the call fails with error.

AttributeError: 'NoneType' object has no attribute 'get_text'

I can try the attrib=element, hard-coding the quotations and it also fails.

What am I missing here?

UPDATE:

prodTitle = page.find(str(tag), {str(attrib): "ourId"}).get_text(strip=True) This code works

prodTitle = page.find(str(tag), {str(attrib): str(element)}).get_text(strip=True) This code does not work, with or without str() or quotes passed.

Answer 1

This is one way you can use variables in bs4 (python version >= 3.6):

from bs4 import BeautifulSoup

html = '<h3 id="ourId">Something</h3>'

soup = BeautifulSoup(html, 'html.parser')

prodTitle = soup.find("h3", {"id": "ourId"}).get_text(strip=True)

tag="h3"
attrib="id"
element="ourId"

var_prodTitle = soup.find(f"{tag}", {f"{attrib}" : f"{element}"}).text.strip()
print('prodTitle', prodTitle)
print('_______________')
print('var_prodTitle', var_prodTitle)

Result:

prodTitle Something
_______________
var_prodTitle Something