Question

I do this a lot in Perl:

printf "%8s %8s %8s\n", qw(date price ret);

However, the best I can come up with in Python is

print '%8s %8s %8s' % (tuple("date price ret".split()))

I’m just wondering if there is a more elegant way of doing it? I’m fine if you tell me that’s it and no improvement can be made.

Answer 1

Well, there’s definitely no way to do exactly what you can do in Perl, because Python will complain about undefined variable names and a syntax error (missing comma, perhaps). But I would write it like this (in Python 2.X):

print '%8s %8s %8s' % ('date', 'price', 'ret')

If you’re really attached to Perl’s syntax, I guess you could define a function qw like this:

def qw(s):
    return tuple(s.split())

and then you could write

print '%8s %8s %8s' % qw('date price ret')

which is basically Perl-like except for the one pair of quotes on the argument to qw. But I’d hesitate to recommend that. At least, don’t do it only because you miss Perl – it only enables your denial that you’re working in a new programming language now 😉 It’s like the old story about Pascal programmers who switch to C and create macros

#define BEGIN {
#define END   }