strip newlines and blanks

[micklee74@hotmail.com]

hi
i have a file test.dat eg

abcdefgh
ijklmn
<-----newline
opqrs
tuvwxyz


I wish to print the contents of the file such that it appears:
abcdefgh
ijklmn
opqrs
tuvwxyz

here is what i did:
f = open("test.dat" )
while 1:
line = f.readline().rs trip("\n")
if line == '':
break
print line

but it always give me first 2 lines, ie
abcdefgh
ijklmn

What can i do to make it print all w/o the newlines..? and what is the
proper way to skip printing blank lines while iterating file contents?

thanks

[Peter Otten]

Re: strip newlines and blanks

micklee74@hotma il.com wrote:

Mick, you should be a bit more patient. Allow for some time for an answer to
arrive. Minor edits of your question don't warrant a repost.
[color=blue]
> i have a file test.dat eg
>
> abcdefgh
> ijklmn
> <-----newline
> opqrs
> tuvwxyz
>
>
> I wish to print the contents of the file such that it appears:
> abcdefgh
> ijklmn
> opqrs
> tuvwxyz
>
> here is what i did:
> f = open("test.dat" )
> while 1:
> line = f.readline().rs trip("\n")
> if line == '':
> break
> print line
>
> but it always give me first 2 lines, ie
> abcdefgh
> ijklmn
>
> What can i do to make it print all w/o the newlines..? and what is the
> proper way to skip printing blank lines while iterating file contents?[/color]

The end of the file is signalled by an empty string, and a blank line with
the trailing "\n" stripped off is an empty string, too. Therefore you have
to perform the line == '' test before the stripping.

Here's an alternative approach:

for line in f:
line = line.rstrip()
if line:
print line

This will ignore any lines containing only whitespace and remove trailing
whitespace from the non-white lines.

Peter

[Fredrik Lundh]

Re: strip newlines and blanks

micklee74@hotma il.com wrote:
[color=blue]
> i have a file test.dat eg
>
> abcdefgh
> ijklmn
> <-----newline
> opqrs
> tuvwxyz
>
>
> I wish to print the contents of the file such that it appears:
> abcdefgh
> ijklmn
> opqrs
> tuvwxyz
>
> here is what i did:
> f = open("test.dat" )
> while 1:
> line = f.readline().rs trip("\n")
> if line == '':
> break
> print line
>
> but it always give me first 2 lines, ie
> abcdefgh
> ijklmn
>
> What can i do to make it print all w/o the newlines..? and what is the
> proper way to skip printing blank lines while iterating file contents?[/color]

assuming you want to skip *all* blank lines (even if they have whitespace
on them),

for line in open("test.dat" ):
if line.strip():
print line

</F>

[micklee74@hotmail.com]

Re: strip newlines and blanks

thanks..and sorry, i am using the web version of google groups and
didn't find an option i can edit my post, so i just removed it..
thanks again for the reply..

[Sybren Stuvel]

Re: strip newlines and blanks

micklee74@hotma il.com enlightened us with:[color=blue]
> thanks..and sorry, i am using the web version of google groups and
> didn't find an option i can edit my post[/color]

It's usenet, you can't edit posts.
[color=blue]
> so i just removed it..[/color]

Which doesn't work at all. Stupid thing they allow you to try and
delete something on Google Groups, since removal of Usenet posts is
ignored by most Usetnet carriers.

Sybren
--
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself?
Frank Zappa

[Kent Johnson]

Re: strip newlines and blanks

micklee74@hotma il.com wrote:[color=blue]
> hi
> i have a file test.dat eg
>
> abcdefgh
> ijklmn
> <-----newline
> opqrs
> tuvwxyz
>
>
> I wish to print the contents of the file such that it appears:
> abcdefgh
> ijklmn
> opqrs
> tuvwxyz
>
> here is what i did:
> f = open("test.dat" )
> while 1:
> line = f.readline().rs trip("\n")
> if line == '':
> break[/color]

break terminates the loop, so no more lines will be processed. Use
continue, which ends only the current iteration of the loop. (Though you
will need a separate test to terminate the loop when there are no more
lines.)

You can iterate an open file directly; here is a shorter version:

for line in open('test.dat' ):
line = line.rstrip('\n ')
if line:
print line

Kent
[color=blue]
> print line
>
> but it always give me first 2 lines, ie
> abcdefgh
> ijklmn
>
> What can i do to make it print all w/o the newlines..? and what is the
> proper way to skip printing blank lines while iterating file contents?
>
> thanks
>[/color]