IDLE: Fix and update and cleanup pyparse

GitHub fields:

assignee = 'https://github.com/terryjreedy'
closed_at = None
created_at = <Date 2018-02-20.02:19:14.840>
labels = ['3.8', 'expert-IDLE', 'type-bug', '3.7']
title = 'IDLE: Fix and update and cleanup pyparse'
updated_at = <Date 2018-03-03.00:44:56.033>
user = 'https://github.com/terryjreedy'

bugs.python.org fields:

activity = <Date 2018-03-03.00:44:56.033>
actor = 'cheryl.sabella'
assignee = 'terry.reedy'
closed = False
closed_date = None
closer = None
components = ['IDLE']
creation = <Date 2018-02-20.02:19:14.840>
creator = 'terry.reedy'
dependencies = ['32905', '32916', '32940', '32989']
files = []
hgrepos = []
issue_num = 32880
keywords = []
message_count = 21.0
messages = ['312394', '312395', '312398', '312444', '312464', '312474', '312477', '312525', '312526', '312544', '312549', '312568', '312607', '312726', '312737', '312741', '312744', '312830', '312875', '312876', '312877']
nosy_count = 3.0
nosy_names = ['terry.reedy', 'serhiy.storchaka', 'cheryl.sabella']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'test needed'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue32880'
versions = ['Python 3.6', 'Python 3.7', 'Python 3.8']