Assuming the parenthesis do not nest, and that there is at most one pair per string, try this:
import re
myString = re.sub(r'\(.*\)', '', myString)
A more specific pattern might be:
myString = re.sub(r'\s*\(\w+\)\s*$', '', myString)
The above pattern deletes the whitespace that surrounds the parenthetical expression, and only deletes from the end of the line.