[IPython-dev] Invalid cp0 encoding

[Dave Hirschfeld]

Just pinging the list to mention my attempt at a PR 
(https://github.com/ipython/ipython/pull/4163) to fix the error I was 
encountering below.

Whilst trying out rendering notebooks in a flask app under Apache on Windows 
I got the below error when simply trying to import `SlidesExporter`:

```
mod_wsgi (pid=6260): Exception occurred processing WSGI script 
'flask_test.wsgi'.
Traceback (most recent call last):
  File "flask_test.py", line 81, in render_notebook
    from IPython.nbconvert.exporters import SlidesExporter
  File "c:\\dev\\code\\ipython\\IPython\\__init__.py", line 47, in <module>
    from .terminal.embed import embed
  File "c:\\dev\\code\\ipython\\IPython\\terminal\\embed.py", line 32, in 
<module>
    from IPython.terminal.interactiveshell import TerminalInteractiveShell
  File "c:\\dev\\code\\ipython\\IPython\\terminal\\interactiveshell.py", 
line 25, in <module>
    from IPython.core.interactiveshell import InteractiveShell, 
InteractiveShellABC
  File "c:\\dev\\code\\ipython\\IPython\\core\\interactiveshell.py", line 
59, in <module>
    from IPython.core.prompts import PromptManager
  File "c:\\dev\\code\\ipython\\IPython\\core\\prompts.py", line 138, in 
<module>
    HOME = 
py3compat.str_to_unicode(os.environ.get("HOME","//////:::::ZZZZZ,,,~~~"))
  File "c:\\dev\\code\\ipython\\IPython\\utils\\py3compat.py", line 18, in 
decode
    return s.decode(encoding, "replace")
LookupError: unknown encoding: cp0
```

NB: Although it now works great I have no idea what the second argument 
returned by `SlidesExporter.from_filename` is or is for. Is there any 
documentation on this?

```
In [34]: html, resources = exporter.from_filename('testnotebook.ipynb')

In [35]: type(resources)
Out[35]: IPython.nbconvert.exporters.exporter.ResourcesDict

In [36]: resources.keys()
Out[36]: ['reveal', 'inlining', 'output_extension', 'metadata']

In [37]: print IPython.sys_info()
{'codename': 'An Afternoon Hack',
 'commit_hash': 'ee40094',
 'commit_source': 'repository',
 'default_encoding': 'cp1252',
 'ipython_path': 'c:\\dev\\code\\ipython\\IPython',
 'ipython_version': '2.0.0-dev',
 'os_name': 'nt',
 'platform': 'Windows-2008ServerR2-6.1.7601-SP1',
 'sys_executable': 'C:\\dev\\bin\\Python27\\python.exe',
 'sys_platform': 'win32',
 'sys_version': '2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit 
(AMD64)]'}
```

Thanks,
Dave