print with variable justification (with *)

[John Machin]

tom wrote:
> Why Tea wrote:
> > print format % values
> > An optional minimum width of the conversion, specified using one or
> > more digits or an asterisk (*), which means that the width is taken
> > from the next item in values
> >
> > That's from one of O'reilly's books. But there is no example and I
> > couldn't get it to work by trials and errors. Does anyone have a
> > working example?
> >
> > /Why Tea
> >
> >
> value = 3.141592654
> print "%1.3f" % value

Please consider reading the subject of a message occasionally :)

| >>> value = 3.141592654
| >>> print "%1.3f" % value
| 3.142
| >>> print "%10.3f" % value
|      3.142
| >>> print "%*.3f" % (1, value)
| 3.142
| >>> print "%*.3f" % (10, value)
|      3.142
| >>> for n in range(11):
| ...     print "%*.3f" % (n, value)
| ...
| 3.142
| 3.142
| 3.142
| 3.142
| 3.142
| 3.142
|  3.142
|   3.142
|    3.142
|     3.142
|      3.142
| >>>
> >
> there you go :)

There *you* go :)

>  look at printf in c for general ideas about the format
> specifiers

Unfortunately this is about the same advice as given by the official
Python tutorial:

"""Most formats work exactly as in C [snip] Using * to pass the width
or precision in as a separate (integer) argument is supported"""

Not quite so many folks come to Python with a background in C these
days. Is anyone aware of a tutorial that covers % formatting from a
standing start?

Cheers,
John