Test if children tag exists in beautifulsoup

Question

i have an XML file with an defined structure but different number of tags, like

file1.xml:

<document>
  <subDoc>
    <id>1</id>
    <myId>1</myId>
  </subDoc>
</document>

file2.xml:

<document>
  <subDoc>
    <id>2</id>
  </subDoc>
</document>

Now i like to check, if the tag myId exits. So i did the following:

data = open("file1.xml",'r').read()
xml = BeautifulSoup(data)

hasAttrBs = xml.document.subdoc.has_attr('myID')
hasAttrPy = hasattr(xml.document.subdoc,'myID')
hasType = type(xml.document.subdoc.myid)

The result is for file1.xml:

hasAttrBs -> False
hasAttrPy -> True
hasType ->   <class 'bs4.element.Tag'>

file2.xml:

hasAttrBs -> False
hasAttrPy -> True
hasType -> <type 'NoneType'>

Okay, <myId> is not an attribute of <subdoc>.

But how i can test, if an sub-tag exists?

//Edit: By the way: I'm don't really like to iterate trough the whole subdoc, because that will be very slow. I hope to find an way where I can direct address/ask that element.

Answer 1

if tag.find('child_tag_name'):

Answer 2

The simplest way to find if a child tag exists is simply

childTag = xml.find('childTag')
if childTag:
    # do stuff

---

More specifically to OP's question:

If you don't know the structure of the XML doc, you can use the .find() method of the soup. Something like this:

with open("file1.xml",'r') as data, open("file2.xml",'r') as data2:
    xml = BeautifulSoup(data.read())
    xml2 = BeautifulSoup(data2.read())

    hasAttrBs = xml.find("myId")
    hasAttrBs2 = xml2.find("myId")

If you do know the structure, you can get the desired element by accessing the tag name as an attribute like this xml.document.subdoc.myid. So the whole thing would go something like this:

with open("file1.xml",'r') as data, open("file2.xml",'r') as data2:
    xml = BeautifulSoup(data.read())
    xml2 = BeautifulSoup(data2.read())

    hasAttrBs = xml.document.subdoc.myid
    hasAttrBs2 = xml2.document.subdoc.myid
    print hasAttrBs
    print hasAttrBs2

Prints

<myid>1</myid>
None

Answer 3

Here's an example to check if h2 tag exists in an Instagram URL. Hope you find it useful:

import datetime
import urllib
import requests
from bs4 import BeautifulSoup

instagram_url = 'https://www.instagram.com/p/BHijrYFgX2v/?taken-by=findingmero'
html_source = requests.get(instagram_url).text
soup = BeautifulSoup(html_source, "lxml")

if not soup.find('h2'):
    print("didn't find h2")

Answer 4

you can handle it like this:

for child in xml.document.subdoc.children:
    if 'myId' == child.name:
       return True