allow creation of "symtable entry" objects from Python

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-01-22.23:44:18.248>
labels = ['type-feature']
title = 'allow creation of "symtable entry" objects from Python'
updated_at = <Date 2020-01-22.23:44:18.248>
user = 'https://github.com/carljm'

bugs.python.org fields:

activity = <Date 2020-01-22.23:44:18.248>
actor = 'carljm'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = []
creation = <Date 2020-01-22.23:44:18.248>
creator = 'carljm'
dependencies = []
files = []
hgrepos = []
issue_num = 39428
keywords = []
message_count = 1.0
messages = ['360522']
nosy_count = 1.0
nosy_names = ['carljm']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue39428'
versions = []