Missing def'n of equality for set elements

[smontanaro]

BPO	1179957
Nosy	@smontanaro, @rhettinger

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2005-04-10.17:30:04.000>
created_at = <Date 2005-04-09.22:10:45.000>
labels = ['docs']
title = "Missing def'n of equality for set elements"
updated_at = <Date 2005-04-10.17:30:04.000>
user = 'https://github.com/smontanaro'

bugs.python.org fields:

activity = <Date 2005-04-10.17:30:04.000>
actor = 'rhettinger'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2005-04-09.22:10:45.000>
creator = 'skip.montanaro'
dependencies = []
files = []
hgrepos = []
issue_num = 1179957
keywords = []
message_count = 3.0
messages = ['24971', '24972', '24973']
nosy_count = 2.0
nosy_names = ['skip.montanaro', 'rhettinger']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1179957'
versions = ['Python 2.5']

[smontanaro]

The documentation of the sets module doesn't describe the
properties of set elements that they must have to properly
work in sets (at least I didn't see it described). In creating a
set of instances, I had to sort of stumble around and
discover that the class needed to define both __eq__ and
__hash__. Either alone didn't seem to work. Perhaps I've
got it all wrong and there's a better way to do things. It would
be nice if the docs described things officially though.

[rhettinger]

Logged In: YES
user_id=80475

It does say that sets are implemented using dictionaries. That
implies that the requirements for set elements are the same as for
dictionary keys.

Will see if I can add some clarifying wording.

[rhettinger]

Logged In: YES
user_id=80475

Updated both libstdtypes.tex and libsets.tex with explicit
documentation for element requirements.