get rid of line that is not starting with specific word

I want to get rid of a line from a python file which is not starting with def.

thefile.py has

def showBuilder():
   """ Do something
       And build show
   """

showBuilder()

Now I want to leave the line def showBuilder as is but want to get rid of the line showbuilder() at the bottom

I tried

sed '/^def / s/showBuilder()//' thefile.py

but this is returning

def :
   """ Do something
       And build show
   """

showBuilder()

would love to use anything that works, sed is just my try.

>Solution :

So match the line and the delete it.

sed '/^showBuilder()$/d'

You might find simpler to just:

grep -vxF 'showBuilder()'