Update column under dataframe by regex
One of the possible solutions:
df["price_int"] = df["price"].apply(lambda value: int(value.split(" ")[0]))
Or you can use Regex (more robust):
df["price_int"] = df["price"].str.extract(r'(^[0-9]+)').astype(int)
I have got a dataframe looks like this:

12000 pa
13000 per annum
25000 pa
34000 per annum

I need to update all four cells into int only, so:

12000
13000
25000
34000

What is the quickest method for doing this?