Python output

MTK358 · 06-14-2010, 04:22 PM

I have two questions about Python's print statement:

1) How to make it not stick spaces and newlines between items in its provided list?

2) How to print to stderr?

rweaver · 06-14-2010, 04:40 PM

Your first question is a bit ambiguous, provide an example of what you mean, in answer to your second question:

Code:

#!/usr/bin/python
import sys
print >> sys.stderr, 'this goes to stderr'
print >> sys.stdout, 'this goes to stdout'

Code:

core:~/vir$ ./test.py
this goes to stderr
this goes to stdout
core:~/vir$ ./test.py 2>std.err
this goes to stdout
core:~/vir$ ./ test.py 1>std.out
this goes to stderr
core:~/vir$

Edit: on second thought--

Code:

#!/usr/bin/python
import sys
print 'this', 'is', 'a', 'list', 'of', 'items.'
sys.stdout.write("%s%s%s\n" % ("3.14", "pi.", " mmmmm pie."))

Code:

core:~/vir$ test2.py
this is a list of items.
3.14pi. mmmmm pie.
core:~/vir$

I think is what you were looking for.

JohnGraham · 06-14-2010, 05:51 PM

As for newlines in a regular print - to not stick a newline at the end, stick a comma at the end:

Code:

>>> print 'no newline between here',
... print 'and here'
no newline between here and here

Don't think there's a 'quick' way for spaces, you have to do what rweaver suggested.

Sergei Steshenko · 06-14-2010, 07:25 PM

Quote:

Originally Posted by MTK358

I have two questions about Python's print statement:

1) How to make it not stick spaces and newlines between items in its provided list?

2) How to print to stderr?

Just wondering - entering

Python print stderr

into yahoo.com as the third match I see:

http://diveintopython.org/scripts_an...ut_stderr.html
.

And there is an example:

Code:

Example 10.11. Printing to stderr

>>> print 'entering function'
entering function
>>> import sys
>>> print >> sys.stderr, 'entering function' 1
entering function

.

So, do yo perform WEB search and can you use 'Find' function of your favorite WEB browser ?

So, did you at all try WEB search ? Do

Sergei Steshenko · 06-14-2010, 08:02 PM

And, MTK358, entering into Yahoo

Python print newline

as the second match I'm getting:

http://codingrecipes.com/print-witho...pace-in-python

- do you see "print-without-a-new-line-or-space-in-python" in the URL ?

And you know, indeed there is an example:

Code:

Now, you can fix the issue with the line break by inserting a comma after the print statement:

print "Hello",
print "Python",
print "!"

This will print:
Hello Python !

But the problem is that it will still insert a space after it prints the text, so to fix this you will have to use sys.stdout.write like this:

import sys
sys.stdout.write("Hello ")
sys.stdout.write("Python")
sys.stdout.write("!")

This will print:
Hello Python!

So, do yo perform WEB search and can you use 'Find' function of your favorite WEB browser ?