PEP 214 - Why not print >> string?

[Alex Martelli]

"Aaron Swartz" <me at aaronsw.com> wrote in message
news:B8631E26.17D53%me at aaronsw.com...
    ...
>     def tables(n, file=None):
>         for j in range(1, n+1):
>             for i in range(1, n+1):
>                 print >> file, i, 'x', j, '=', i*j
>             print >> file
    ...
> I'd like to suggest that one be able to provide a variable in addition to
a
> print statement. Thus, the tables function above could be rewritten as:
>
>     def tables(n):
>         output = ''
>         for j in range(1, n+1):
>             for i in range(1, n+1):
>                 print >> output, i, 'x', j, '=', i*j
>             print >> output
>         return output
>
> This would be backwards compatible as currently >>ing to a string raises
an
> error. What do others thing about this?

I think it would be an utter disaster, and in that sense quite compatible
indeed with "print >>".  Have "print >> foo, something" rebind name foo if
foo names a string (and build up the resulting string by the disasterous
equivalent of +=) is, in my opinion, a terrible idea.

def tables(n):
    format = "%d x %d = %d"
    output = []
    for j in range(1, n+1):
        for i in range(1, n+1):
            output.append(format % (i, j, i*j))
        output.append('')
    return '\n'.join(output)

that's how I'd code it myself...


Alex