simplify printing of a list

[Peter Otten]

beliavsky at aol.com wrote:

> To print a list with a specified format one can write (for example)
> 
> for j in [0,1,2]:
>     print "%6d"%j,
> print
> 
> The code
> 
> print "%6d"%[0,1,2]
> 
> currently produces a syntax error, but it would be convenient if it
> had the same meaning as the loop above.

A TypeError. What if I wanted the current behaviour, e. g

>>> "%s" % [1, 2, 3]
'[1, 2, 3]'

instead of

>>> "%s" % [1, 2, 3] 
'1 2 3' #faked

> 
> One can write a function to print a list, for example
> 
> def print_list(x,fmt_x="%6d"):
>     """ print a list on one line """
>     for y in x: print fmt_x % y,
> 
> print_list([0,1,2])
> 
> but it gets messy to print several lists on the same line.

How about different operators for the two formatting operations:

>>> class Format(str):
...     def __mul__(self, other):
...             return " ".join(map(self.__mod__, other))
...
>>>
>>> Format("%6d") % 1
'     1'
>>> Format("%6d") * [1, 2, 3]
'     1      2      3'
>>>

Peter