Home Original page

print without newline?

Alex Martelli aleaxit at yahoo.com
Sat Sep 2 09:52:04 EDT 2000 
"Ian Hobson" <ian.hobson at ntlworld.com> wrote in message
news:nbnhlPA$UEs5Ew4W at ntlworld.com...
    [snip]
> >>Is there a way to print without the newline (carriage return
> >>or line feed)? This does not do what I want:
> >>        print "Hello.",
> >>because it puts a space after the "Hello."
> >
> >Actually, it doesn't put a space after the "Hello.", the next print
> >statement puts a space before its output.
>
> I'm sure there is logic behind this choice, but it escapes me.
> Can anyone explain why print should put a space out first?

The print statement is (was) meant mainly as a convenience for
beginners & rapid insertion of "let's see what it's doing here" in
a program that's behaving strangely.  If it didn't use spaces by
default, then if you had
    print x,
and later
    print y,
and saw the output
1234
you'd have no way to know whether x was 1 and y 234, or x
was 12 and y was 34.  The space-by-default helps.


> And can they confirm that the FIRST print in the program does not.

Just bind sys.output.softspace to 0 before any print, and you
can be sure it won't emit the initial space.  E.g. interactively:

>>> print 12, ; print 34
12 34
>>> print 12, ; sys.stdout.softspace=0 ; print 34
1234
>>>

This of course suggests the usual kind of wrapping-object
trickery, e.g....:

class nospaces:
    def __init__(self,afile):
        self.afile=afile
    def __getattr__(self,attr):
        if attr=='softspace': return 0
        else: return getattr(self.afile,attr)
    def __setattr__(self,attr,value):
        if attr=='softspace': return
        else: self.__dict__[attr]=value

>>> sys.stdout=Script1.nospaces(sys.stdout)
>>> print 12, ; print 34
1234
>>>

...but, resist the temptation: entertainment value apart,
using sys.stdout.write(str(foo)) (you can of course easily
wrap that in a function) is really simpler and more effective
than softspace trickery, IMHO.


Alex
More information about the Python-list mailing list