How to replace strings in pandas column that are in a list?

I have scrolled through the posts on this question and was unable to find an answer to my situation. I have a pandas dataframe with a list of company names, some of which are represented as their domain name.

df = pd.DataFrame(['amazon.us', 'pepsi', 'YOUTUBE.COM', 'apple.inc'], columns=['firm'])

I want to remove the domain extension from all the strings. The extensions are given in a list:

web_domains = ['.com', '.us']

The ollowing attepmt did not yield any results:

df['firm'].str.lower().replace(web_domains, '')

Can someone please help me out, and possibly also explain why my solution does not work?

>Solution :

You need use regex=True for Series.replace since it matches exact string under regex=False.

For example a will only be replaced when target is a not ab nor bab

web_domains = ['\.com', '\.us'] # escape `.` for regex=True

df['removed'] = df['firm'].str.lower().replace(web_domains, '', regex=True)

print(df)

          firm    removed
0    amazon.us     amazon
1        pepsi      pepsi
2  YOUTUBE.COM    youtube
3    apple.inc  apple.inc