[Tutor] file operations and formatting

[Scott Widney]

> a=99.99 # a float
> b='hello world'
> file=open('junk.txt','w')
> 
> What I want is to write a and b to junk.txt with a space in 
> between (I'm using file.write).

### Here's the short answer
>>> a = 99.99
>>> b = 'hello world'
>>> fd = file('junk.txt', 'w')
>>> fd.write("%f %s" % a, b)

> I tried using a format to write, but that didn't work - 
> mostly because I think that I don't understand formatting
> as well as I should. So does anyone have a good
> reference/tutorial for formatting?

You'll find the options and descriptions to use in formatting statements in
the Python Library Reference, section 2.2.6.2 String Formatting Operations.
Here's a shortcut:

http://www.python.org/doc/current/lib/typesseq-strings.html#l2h-148


Enjoy!
Scott