random.sample() docs unclear on k < len(population)

[roysmith]

BPO	15265
Nosy	@rhettinger
Files	issue15265-fix-docs.patch issue15265-fix-docs-update.patch

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

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GitHub fields:

assignee = 'https://github.com/rhettinger'
closed_at = <Date 2012-07-08.23:02:27.161>
created_at = <Date 2012-07-06.17:50:44.677>
labels = ['type-feature', 'docs']
title = 'random.sample() docs unclear on k < len(population)'
updated_at = <Date 2012-07-08.23:02:27.160>
user = 'https://bugs.python.org/roysmith'

bugs.python.org fields:

activity = <Date 2012-07-08.23:02:27.160>
actor = 'rhettinger'
assignee = 'rhettinger'
closed = True
closed_date = <Date 2012-07-08.23:02:27.161>
closer = 'rhettinger'
components = ['Documentation']
creation = <Date 2012-07-06.17:50:44.677>
creator = 'roysmith'
dependencies = []
files = ['26285', '26296']
hgrepos = []
issue_num = 15265
keywords = ['patch']
message_count = 6.0
messages = ['164742', '164803', '164843', '164845', '165043', '165044']
nosy_count = 5.0
nosy_names = ['rhettinger', 'roysmith', 'docs@python', 'python-dev', 'kmox83']
pr_nums = []
priority = 'low'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue15265'
versions = []

[roysmith]

The docs don't say what happens if you call random.sample() with a population smaller than k. Experimentally, it raises ValueError, but this should be documented.

I would have guessed it would return IndexError, by analogy to random.choice().

[kmox83]

Added the related line to the documentation describing when the exception is raised.

[roysmith]

The docs describe population as a "sequence". Your patch describes it as a "list". I would go with:

If *len(population)* is less than *k*, raises :exc:`ValueError`.

[kmox83]

Ok, I have updated the patch

[python-dev]

New changeset 72174d8af3ba by Raymond Hettinger in branch 'default':
bpo-15265: document the exception raised for invalid sample sizes.
http://hg.python.org/cpython/rev/72174d8af3ba

[rhettinger]

Thanks, I've added a note.