poor documentation for .startswith, .endswith

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-07-03.05:01:35.684>
labels = ['docs']
title = 'poor documentation for .startswith, .endswith'
updated_at = <Date 2020-09-19.18:03:39.370>
user = 'https://bugs.python.org/vpython'

bugs.python.org fields:

activity = <Date 2020-09-19.18:03:39.370>
actor = 'iritkatriel'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2019-07-03.05:01:35.684>
creator = 'v+python'
dependencies = []
files = []
hgrepos = []
issue_num = 37490
keywords = []
message_count = 9.0
messages = ['347179', '347180', '347185', '347187', '347188', '347189', '347194', '347195', '347212']
nosy_count = 5.0
nosy_names = ['holdenweb', 'v+python', 'steven.daprano', 'docs@python', 'aldwinaldwin']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue37490'
versions = []