regex - Errors when trying to remove parentheses in python text -

i've been working on bit of code take bunch of histograms other files , plot them together. in order make sure legend displays correctly i've been trying take titles of these original histograms , cut out bit of information isn't needed more.

the section don't need takes form (a mass=200 gev), i've had no problem removing what's inside parentheses, unfortunately i've tried parentheses either has no effect, negates code removes text, or throws errors.

i've tried using suggestions from; remove parenthesis , text in file using python , how can remove text within parentheses regex?

the error current attempt gives me is

'str' object cannot interpreted integer 

this section of code:

histo_name = ''  # list of things not want show in our legend keys remove_list = ["(a mass = 200 gev)"]  # these 2 lines use re module remove things piece of text # specified in remove list remove = '|'.join(remove_list) regex = re.compile(r'\b('+remove+r')\b')  # creating correct name stacked histogram histo in histos:      if histo == histos[0]:          # place_holder contains edited string want set         # histogram title         place_holder = regex.sub('', str(histo.getname()))         histo_name += str(place_holder)         histo.settitle(histo_name)      else:          place_holder = regex.sub(r'\(\w*\)', '', str(histo.getname()))         histo_name += ' + ' + str(place_holder)         histo.settitle(histo_name) 

the if/else bit because first histogram pass in isn't getting stacked want keep it's own name, while rest stacked in order hence '+' etc, thought i'd include it.

apologies if i've done obvious wrong, i'm still learning!

from python docs - match literals '(' or ')', use \( or \), or enclose them inside character class: [(] [)].

so use 1 of above patterns instead of plain brackets in regex. e.g.remove_list = ["\(a mass = 200 gev\)"]

edit: issue seems use of \b in regex - according docs linked above matches braces. seemingly-working example is,

import re  # test input myteststring = "somemess (a mass = 200 gev) , other mess (remove me if can)" replacewith = "hey there friend"  # remove removelist = [r"\(a mass = 200 gev\)", r"\(remove me if can\)"]  # build regex remove = r'(' + '|'.join(removelist) + r')' regex = re.compile(remove)  # try it! out = regex.sub(replacewith, myteststring)  # see if worked print(out)