Python : how to extract the first substring of a string with separator into another column?

I have a dataframe with a column "CCR" whose values are as such :
"Aaaa;Bbbb;Cccc", or "Bbbb;;Cccc", or "Cccc;Bbbb;Aaaa".
I would like to take only the first part (before the ";") and put this into another column "1st CCR". I can’t seem to make it work using the split function. With this code I tried, nothing happens.
Can you help ?

def get_1stCCR(row):
  for row in df['CCR']:
    df['1stCCR'] = row.split(";")[0]

df['CCR'].apply(get_1stCCR)

>Solution :

You can do the following using a lambda function:

df['newCCR']=df['CCR'].apply(lambda x:x[0:x.index(';')])

If some rows don’t have ‘;’ in them, you should use:

df['newCCR']=df['CCR'].apply(lambda x:x[0:x.index(';') if ';' in x else None])