import re
content = '''
Blah - blah \n blah * blah + blah.
'''
regex = r'[\n+*/-]'
my_dict = { '+': 'rep1', '\n': 'rep2'}
new_content = re.sub(regex, lambda m: my_dict.get(m.group(),""), content)
print(new_content)
aW1wb3J0IHJlCmNvbnRlbnQgPSAnJycKQmxhaCAtIGJsYWggXG4gYmxhaCAqIGJsYWggKyBibGFoLgonJycKCnJlZ2V4ID0gcidbXG4rKi8tXScKbXlfZGljdCA9IHsgJysnOiAncmVwMScsICdcbic6ICdyZXAyJ30KbmV3X2NvbnRlbnQgPSByZS5zdWIocmVnZXgsIGxhbWJkYSBtOiBteV9kaWN0LmdldChtLmdyb3VwKCksIiIpLCBjb250ZW50KQpwcmludChuZXdfY29udGVudCk=