How to scrape text from HTML excluding tags, that contains specific pattern?

Alternativly you could select your elements a way more specific with a css selector:

soup.select('span.p-body-copy-02:not(:-soup-contains(" Date:"))')

Example

import requests
import pandas as pd
from bs4 import BeautifulSoup

url = "https://www.philips.com/a-w/security/security-advisories"
html_content = requests.get(url).text

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

data = []

for e in soup.select('dd'):
    data.append({
        'title':e.find_previous_sibling('dt').text,
        'content':' '.join([e.get_text(' ', strip=True) for e in e.select('span.p-body-copy-02:not(:-soup-contains(" Date:"))')])
    })

pd.DataFrame(data)

Output

...

You could apply if continue statement or simple(not robust way) list slicing

import pandas as pd
import requests
from bs4 import BeautifulSoup
from requests.models import ContentDecodingError

url = "https://www.philips.com/a-w/security/security-advisories"
# get the html content of the url
html_content = requests.get(url).text
# parse the html content
soup = BeautifulSoup(html_content, 'html.parser')

span_content = []
for span in soup.find_all("span", class_="p-body-copy-02"):
    if 'Publication Date:' in span or 'Update Date:' in span:
           continue
    else:
        span_content.append(span.text)

print(span_content)



# span_content = []
# for span in soup.find_all("span", class_="p-body-copy-02")[2:]:
#     span_content.append(span.text)

# print(span_content)

The following should work on your setup:

import requests
from bs4 import BeautifulSoup
import pandas as pd
import re

url = 'https://www.philips.com/a-w/security/security-advisories'

big_list = []
r = requests.get(url)
soup = BeautifulSoup(r.text, 'html.parser')
parent_div = soup.select_one('dl.p-accordion')
titles = parent_div.select('dt')
for t in titles:
    advisory = t.find_next_sibling('dd')
    try:
        advisory.find('span', string = re.compile("Publication Date")).decompose()
        advisory.find('span', string = re.compile("Update Date")).decompose()
        
    except Exception as e:
        try:
            advisory.find('strong', string = re.compile("Publication Date")).decompose()
            advisory.find('strong', string = re.compile("Update Date")).decompose()
        except Exception as e:
            advisory.find('p', string = re.compile("Publication Date")).decompose()
            advisory.find('p', string = re.compile("Update Date")).decompose()
            
    big_list.append((t.text, advisory.get_text(strip=True)))
    

df = pd.DataFrame(big_list, columns = ['Title', 'Description'])
print(df)

Result:

Title   Description
0   Realtek Advisory (CVE-2022-27255) - (2022 August 25)    Philips is currently monitoring developments and updates related to the Realtek AP-Router SDK Advisory (CVE-2022-27255). Realtek has confirmed that their eCos SDK-based routers, the ‘SIP ALG’ module is vulnerable to buffer overflow.Successful execution of this vulnerability could allow a crash or achieve the remote execution code. Realtek has released a patch that remediate this vulnerability.At this time, no Philips products are known to be impacted. In accordance with Philips’ Global Security Policy, Philips continues to analyze the matter, and further information will be posted on the Philips Product Security Advisory page as appropriate. Philips is committed to ensuring the safety, security, integrity, and regulatory compliance of our products to be deployed and to operate within Philips approved product specifications. Therefore, in accordance with Philips’s policy and regulatory requirements, all changes of configuration or software to Philips’ products (including operating system security updates and patches) may be implemented only in accordance with Philips’s product-specific, verified & validated, authorized, and communicated customer procedures or field actions. If a product does require operating system security updates, configuration changes, or other actions to be taken by our customer or by Philips Customer Services, product-specific service documentation will be produced by Philips’s product teams and made available to Philips service delivery platforms such as the Philips InCenter Customer Portal.Contract-entitled customers may use Philips InCenter and are encouraged to request Philips InCenter access and reference product-specific information posted. If customers still have questions, all customers (contract-entitled or otherwise) are encouraged to contact their local service support team or regional product service support as appropriate for up-to-date information specific to their Philips’ products.
1   Cisco Advisory (CVE-2022-20866) - (2022 August 18)  Philips is currently monitoring developments and updates related to the recently released Ciscoadvisory. Cisco has confirmed a critical vulnerability (CVE-2022-20866) exists in the handling of RSA keys on devices running Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software.Successful execution of this vulnerability could allow an unauthenticated, remote attacker to retrieve an RSA private key. Cisco has released software updates that help remediate this vulnerability.At this time, no Philips products are known to be impacted. In accordance with Philips’ Global Security Policy, Philips continues to analyze the matter, and further information will be posted on the Philips Product Security Advisory page as appropriate.Philips is committed to ensuring the safety, security, integrity, and regulatory compliance of our products to be deployed and to operate within Philips approved product specifications. Therefore, in accordance with Philips’s policy and regulatory requirements, all changes of configuration or software to Philips’ products (including operating system security updates and patches) may be implemented only in accordance with Philips’s product-specific, verified & validated, authorized, and communicated customer procedures or field actions.If a product does require operating system security updates, configuration changes, or other actions to be taken by our customer or by Philips Customer Services, product-specific service documentation will be produced by Philips’s product teams and made available to Philips service delivery platforms such as the Philips InCenter Customer Portal.Contract-entitled customers may use Philips InCenter and are encouraged to request Philips InCenter access and reference product-specific information posted. If customers still have questions, all customers (contract-entitled or otherwise) are encouraged to contact their local service support team or regional product service support as appropriate for up-to-date information specific to their Philips’ products.
[...]

HedgeHog's solution is more elegant tho, and it should work if you would install/update soupsieve. Documentation for soupsieve: https://facelessuser.github.io/soupsieve/

And for BeautifulSoup: https://beautiful-soup-4.readthedocs.io/en/latest/index.html

I think your problem is with the if statement try this function

def delete_date(span_content):
   filtered_span_content = []
   for i in range(len(span_content)):
       if 'Publication Date:' in span_content[i] or 'Update Date:' in span_content[i]:
           continue
       else:
           filtered_span_content.append(span_content[i])
   return filtered_span_content