I just want to get rid of characters (or whatever you want to call it)that has “.xxxxx”

So this is how I want it to look like:

This is what I have tried:

df['Gene_ID'].str.replace('.',''))

but when I do that it only gets rid of the decimal not the characters that comes after the decimal point.

Note: the actual column is much longer than what I am showing on stack which has all that “.xxxx”