[docs] import.sys behavior in IDLE re: Modules tutorial section 6.2

[Zachary Ware]

Hi Robin,

On Thu, Jan 2, 2014 at 12:37 PM, Robin Zimmermann <robin.zimm at gmail.com> wrote:
> To whom it may concern:
>
> I've been slowly working through the tutorial in the Python v3.3.3
> documentation, and I ran into a weird thing with the first example in
> Section 6.2 on http://docs.python.org/3/tutorial/modules.html -
> "Standard Modules".
>
> The first command-line example block says:
>
>>>> import sys
>>>> sys.ps1
> '>>> '
>>>> sys.ps2
> '... '
>>>> sys.ps1 = 'C> '
> C> print('Yuck!')
> Yuck!
> C>
>
> I had just opened a new IDLE window*, typed "import sys", hit enter,
> then typed "sys.ps1" and hit enter. The Python shell returned the
> following error:
>
> ----
>
> Traceback (most recent call last):
>   File "<pyshell#1>", line 1, in <module>
>     sys.ps1
> AttributeError: 'module' object has no attribute 'ps1'
>
> ----
>
> In my confusion, I tried a couple more times; the transcript of
> everyhing following the above AttributeError follows:
>
> ----
>
>>>> ps1
> Traceback (most recent call last):
>   File "<pyshell#2>", line 1, in <module>
>     ps1
> NameError: name 'ps1' is not defined
>>>> sys.ps1
> Traceback (most recent call last):
>   File "<pyshell#3>", line 1, in <module>
>     sys.ps1
> AttributeError: 'module' object has no attribute 'ps1'
>>>> dir sys
> SyntaxError: invalid syntax
>>>> dir(sys)
> ['__displayhook__', '__doc__', '__excepthook__', '__loader__',
> '__name__', '__package__', '__stderr__', '__stdin__', '__stdout__',
> '_clear_type_cache', '_current_frames', '_debugmallocstats',
> '_getframe', '_home', '_mercurial', '_xoptions', 'api_version',
> 'argv', 'base_exec_prefix', 'base_prefix', 'builtin_module_names',
> 'byteorder', 'call_tracing', 'callstats', 'copyright', 'displayhook',
> 'dllhandle', 'dont_write_bytecode', 'exc_info', 'excepthook',
> 'exec_prefix', 'executable', 'exit', 'flags', 'float_info',
> 'float_repr_style', 'getcheckinterval', 'getdefaultencoding',
> 'getfilesystemencoding', 'getprofile', 'getrecursionlimit',
> 'getrefcount', 'getsizeof', 'getswitchinterval', 'gettrace',
> 'getwindowsversion', 'hash_info', 'hexversion', 'implementation',
> 'int_info', 'intern', 'last_traceback', 'last_type', 'last_value',
> 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks',
> 'path_importer_cache', 'platform', 'prefix', 'setcheckinterval',
> 'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace',
> 'stderr', 'stdin', 'stdout', 'thread_info', 'version', 'version_info',
> 'warnoptions', 'winver']
>
> ----
>
> Finally, without closing the IDLE window, I opened the Command Prompt**:
>
> ----
>
> Microsoft Windows [Version 6.1.7601]
> Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
>
> C:\Users\Packbat>python
> Python 3.3.3 (v3.3.3:c3896275c0f6, Nov 18 2013, 21:18:40) [MSC v.1600 32 bit (In
> tel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import sys
>>>> sys.ps1
> '>>> '
>>>>
>
> ----
>
> My best guess is that IDLE is not a perfectly faithful implementation
> of the command line; if this is the case, I feel it would be helpful
> either to modify the tutorial to note this explicitly or to contact
> the developers of IDLE regarding the discrepancy, if not both.
>
> Thank you for your time and trouble!

This is a known issue, tracked at http://bugs.python.org/issue13657.
This is a limitation of the way IDLE does things, and should
eventually be fixed (though your suggestion to mention this in the
tutorial may happen first).

Thanks for the report!

-- 
Zach