In argparse docs simplify example about argline

[py-user]

BPO	23356
Nosy	@py-user, @berkerpeksag, @wm75
Files	args_ex_argline.diff: python 3.4

^{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/berkerpeksag'
closed_at = <Date 2015-04-26.09:14:04.073>
created_at = <Date 2015-01-31.08:40:39.836>
labels = ['type-feature', 'library', 'docs']
title = 'In argparse docs simplify example about argline'
updated_at = <Date 2015-04-26.09:14:04.072>
user = 'https://github.com/py-user'

bugs.python.org fields:

activity = <Date 2015-04-26.09:14:04.072>
actor = 'berker.peksag'
assignee = 'berker.peksag'
closed = True
closed_date = <Date 2015-04-26.09:14:04.073>
closer = 'berker.peksag'
components = ['Documentation', 'Library (Lib)']
creation = <Date 2015-01-31.08:40:39.836>
creator = 'py.user'
dependencies = []
files = ['37934']
hgrepos = []
issue_num = 23356
keywords = ['patch']
message_count = 6.0
messages = ['235089', '235090', '241932', '242051', '242052', '242053']
nosy_count = 5.0
nosy_names = ['docs@python', 'py.user', 'python-dev', 'berker.peksag', 'wolma']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue23356'
versions = ['Python 2.7', 'Python 3.4', 'Python 3.5']

[py-user]

The example is:

def convert_arg_line_to_args(self, arg_line):
    for arg in arg_line.split():
        if not arg.strip():
            continue
        yield arg

str.split() with default delimiters never returns empty or whitespace strings in the list.

>>> '  x  x  '.split()
['x', 'x']
>>> '  '.split()
[]
>>>

Therefore, the if condition doesn't ever continue the loop.
It can be written:

def convert_arg_line_to_args(self, arg_line):
    for arg in arg_line.split():
        yield arg

It's the same as:

def convert_arg_line_to_args(self, arg_line):
    return iter(arg_line.split())

I guess, nothing uses next() for the result:

def convert_arg_line_to_args(self, arg_line):
    return arg_line.split()

Applied a patch with the last variant.

[py-user]

Url
https://docs.python.org/3/library/argparse.html#customizing-file-parsing

[berkerpeksag]

LGTM

[python-dev]

New changeset bd8b99034121 by Berker Peksag in branch '3.4':
Issue bpo-23356: Simplify convert_arg_line_to_args example.
https://hg.python.org/cpython/rev/bd8b99034121

New changeset 2d3ed019bc9f by Berker Peksag in branch 'default':
Issue bpo-23356: Simplify convert_arg_line_to_args example.
https://hg.python.org/cpython/rev/2d3ed019bc9f

[python-dev]

New changeset 050e0c0b3d90 by Berker Peksag in branch '2.7':
Issue bpo-23356: Simplify convert_arg_line_to_args example.
https://hg.python.org/cpython/rev/050e0c0b3d90

[berkerpeksag]

Thanks py.user.