> On Jun 9, 2017, at 5:41 PM, Terry J. Reedy <report@bugs.python.org> wrote:
> 
> 
> Terry J. Reedy added the comment:
> 
> Richard, when replying by email, please strip quoted text except for an occasional line or two.  (See example of limited in-context quote below.)
> 
> A bug, for the purpose of this tracker, is a discrepancy between between the docs written by the PSF's core development team and the code provided by the same.  The PSF curses module is documented as unix-only.  In particular, "This extension module is designed to match the API of ncurses, an open-source curses library hosted on Linux and the BSD variants of Unix."  It does not run on the PSF (python.org) Windows distribution, because there is no C interface to a Windows implementation of curses.
> 

Cygwin is a Linux-like (Unix-compatible) command line interface and run-time environment plug-in for Windows. My cross-platform Python code does not use a PSF Windows implementation. It only uses the standard Python 2x and Python 3x curses library module low level API to emulate a subset of the wxPython high-level API. It has been run successfully with xterm (8-color) and xterm-16color terminal emulators (including the ones provided with all Cygwin releases since 2007). All platforms manifest the same failure when my software attempts to use the xterm-256color terminal emulator:

PC-BSD 10.3 Unix
TrueOS (PC-BSD) 12.0 Unix
MacOS X 7.0-10.12.5 (Darwin & BSD Unix based)
Oracle OpenSolaris 11
OpenIndiana Hipster-1610 Solaris 1
CentOS Linux 7.2 & 7.3
Debian Linux 8.7.0 & 8.8.0
Fedora Linux 24 & 25
Scientific Linux 7.2 & 7.3
Windows  XP, 7, 8.1 and 10 (each with Cygwin plug-in)

I am reporting this issue to PSF because I suspect that the standard Python 3.6.1 curses libraries has not be updated to support more that 16 colors on 64-bit platforms. None of my non-Windows 64-bit platforms currently incorporate ncurses 6.0 or Python 3.6.1. I’m anxiously waiting for new releases to those non-windows operating systems.

>>>> import curses  # 64-bit 3.6.1 on Win 10 using python.org installer
> Traceback (most recent call last):
>  File "<pyshell#4>", line 1, in <module>
>    import curses
>  File "C:\Programs\Python36\lib\curses\__init__.py", line 13, in <module>
>    from _curses import *
> ModuleNotFoundError: No module named '_curses'
> 
> Anything Cygwin does to improve on this is their responsibility.
> 
>> how do you explain my success in running my wxPython emulation on all Cygwin releases since 2007
> 
> One or more people on the wxPython and/or Cygwin and/or other teams exerted the effort to make this happen.

wxPython is a pixel-mode GUI. It does use the character-mode curses or ncurses libraries.

Cygwin provides both X11 pixel-mode graphics and ncurses-based character-mode graphics.
> 
> ----------
> nosy: +terry.reedy
> resolution:  -> third party
> stage: test needed -> resolved
> status: open -> closed
> 
> _______________________________________
> Python tracker <report@bugs.python.org>
> <http://bugs.python.org/issue30609>
> _______________________________________