[Tutor] create an xls file using data from a txt file

[Steve Willoughby]

On 11-May-11 12:14, James Reynolds wrote:
> Actually, I never knew that about the windows separators, since I've
> just always used the '\' out of habit.

If you want your code to run everywhere, you should use the functions in 
os.path to manipulate and build paths.

Otherwise, using \ all the time means your code will ONLY ever work on 
Windows.  Using / all the time means your code will work fine on Mac OS 
X, Linux, or other POSIX systems, and PROBABLY ok on Windows most of the 
time, but not on other systems.

>     out path = 'C:\\test.xls', which will be 'C:\test.xls' or you can
>     write out path = r'C:\test.xls' the "r" bit tells python that the
>     following is a regular expression. or regex.

Not to be too pedantic, but since this is a tutorial list, I'll point 
out the more accurate answer so new programmers don't get a mistaken 
impression.

The 'r' string prefix does not actually mean regular expressions.  It 
means "raw string" where (almost) no backslash codes are recognized in 
the string constant, so you could say r'C:\test.xls' instead of 
'c:\\test.xls'.

Raw strings are, however, really useful for strings which hold regular 
expressions, so you see them in that context a lot.

... ah... and I just noticed that this was pointed out later in the 
thread.  Sorry for the repeat there.

>     ‘/’ is perfectly valid Windows separator. See the *tested* examples
>     below. It works just fine pretty much anywhere I have ever tried it,
>     including the command line. (except apparently for an MSOffice file
>     save dialog that I tried just now)

Not... quite.  / is accepted by a number of programs, including the 
Python interpreter, which came from Unix-like systems where / is the 
directory separator.  Very old versions of MSDOS could be configured to 
use / on the command line for pretty much everything, but that has been 
deprecated for a long time now (they originally wanted / for 
command-line switches instead, so used \ for directory separators).

Core windows commands don't generally accept it, including native 
Windows applications (although sometimes they're lenient in what they 
accept).  It'll work for command-line Python script usage because it's 
*python* that allows them, not *windows*.

-- 
Steve Willoughby / steve at alchemy.com
"A ship in harbor is safe, but that is not what ships are built for."
PGP Fingerprint 4615 3CCE 0F29 AE6C 8FF4 CA01 73FE 997A 765D 696C