Vague description of generator close() method

[kermode]

BPO	1616726
Nosy	@akuchling

^{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/akuchling'
closed_at = <Date 2006-12-18.17:30:29.000>
created_at = <Date 2006-12-15.21:09:29.000>
labels = ['docs']
title = 'Vague description of generator close() method'
updated_at = <Date 2006-12-18.17:30:29.000>
user = 'https://bugs.python.org/kermode'

bugs.python.org fields:

activity = <Date 2006-12-18.17:30:29.000>
actor = 'akuchling'
assignee = 'akuchling'
closed = True
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2006-12-15.21:09:29.000>
creator = 'kermode'
dependencies = []
files = []
hgrepos = []
issue_num = 1616726
keywords = []
message_count = 2.0
messages = ['30820', '30821']
nosy_count = 2.0
nosy_names = ['akuchling', 'kermode']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1616726'
versions = ['Python 2.5']

[kermode]

In section 7 of "What's New in Python 2.5" the
subsection on the close() generator method states:

close() raises a new GeneratorExit exception 
inside the generator to terminate the iteration.
On receiving this exception, the generator's code
must either raise GeneratorExit or StopIteration;
catching the exception and doing anything else is
illegal and will trigger a RuntimeError. 

This suggests that if a generator raises a new exception that is neither a GeneratorExit nor
StopIteration a RuntimeError is raised. But this
is not the case according to Part 4 of PEP-342's
"Specification Summary":

If the generator raises any other exception,
it is propagated to the caller.

The Python 2.5 interpreter is consistent with PEP-342:

Python 2.5 (r25:51908, Sep 19 2006, 09:52:17)
 [MSC v.1310 32 bit (Intel)] on win
32
Type "help", "copyright", "credits" or "license" for
 more information.
>>> def raise_wrong_exception():
...     try:
...         yield 1
...         yield 2
...     except GeneratorExit:
...         raise TypeError("Where is the RuntimeError?")
...
>>> i=raise_wrong_exception()
>>> i.next()
1
>>> i.close()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 6, in raise_wrong_exception
TypeError: Where is the RuntimeError?

[akuchling]

You're right; thanks for pointing out the error. Corrected in rev. 53051.