Generic script for finding bugs in get_source_segment

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-03-01.11:59:05.328>
labels = ['interpreter-core', 'type-bug', '3.8', '3.9']
title = 'Generic script for finding bugs in get_source_segment'
updated_at = <Date 2020-03-06.19:19:01.611>
user = 'https://github.com/alexmojaki'

bugs.python.org fields:

activity = <Date 2020-03-06.19:19:01.611>
actor = 'levkivskyi'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core']
creation = <Date 2020-03-01.11:59:05.328>
creator = 'alexmojaki'
dependencies = []
files = ['48940']
hgrepos = []
issue_num = 39810
keywords = []
message_count = 1.0
messages = ['363056']
nosy_count = 2.0
nosy_names = ['levkivskyi', 'alexmojaki']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue39810'
versions = ['Python 3.8', 'Python 3.9']