Check for new line character?

[Yazar Yolait]

I want to skip lines in a file that are blank and that start with "&". So I
strip(None) them and then startswith("&") but the only problem is if the
line has nothing but white space and I strip(None) it then it contains
nothing but a new line character right? So how do I check if the line
contains a new line character? I can no longer use isspace().

[John Roth]

Re: Check for new line character?


"Yazar Yolait" <yazar@hotmail. com> wrote in message
news:bnhk76$v3k lv$1@ID-198839.news.uni-berlin.de...[color=blue]
> I want to skip lines in a file that are blank and that start with "&". So[/color]
I[color=blue]
> strip(None) them and then startswith("&") but the only problem is if the
> line has nothing but white space and I strip(None) it then it contains
> nothing but a new line character right? So how do I check if the line
> contains a new line character? I can no longer use isspace().[/color]

if line == '\n':
whatever...

If you're using <file>.readline () to
read the lines, then each line (except the eof signal) ***will*** end
with a newline, and it will not have a newline internally, so there's no
need for a complicated check. After you strip blanks, an all blank
line will contain exactly one character: the newline.

John Roth[color=blue]
>
>[/color]

[Erik Max Francis]

Re: Check for new line character?

Yazar Yolait wrote:
[color=blue]
> I want to skip lines in a file that are blank and that start with "&".
> So I
> strip(None) them and then startswith("&") but the only problem is if
> the
> line has nothing but white space and I strip(None) it then it contains
> nothing but a new line character right?[/color]

No, the newline character is whitespace as well so you'll be left with
the empty string:
[color=blue][color=green][color=darkred]
>>> ' \n'.strip()[/color][/color][/color]
''[color=blue][color=green][color=darkred]
>>> '&\n'.strip()[/color][/color][/color]
'&'
[color=blue]
> So how do I check if the
> line
> contains a new line character? I can no longer use isspace().[/color]

Pretty basic:

while True:
line = inputFile.readl ine()
if not line:
break
line = line.strip()
if not line or line.startswith ('&'):
continue
...

If the rest of your program is sensitive to (non-newline) whitespace,
then just strip the newline, change

line = line.strip()

to

if line[-1] == '\n':
line = line[:-1]

--
Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/
__ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE
/ \ To endure what is unendurable is true endurance.
\__/ (a Japanese proverb)

[Erik Max Francis]

Re: Check for new line character?

John Roth wrote:
[color=blue]
> If you're using <file>.readline () to
> read the lines, then each line (except the eof signal) ***will*** end
> with a newline, and it will not have a newline internally, so there's
> no
> need for a complicated check.[/color]

Not quite true. It's possible the file will be missing the final
newline, though Python will still treat it as a separate line:

max@oxygen:~/tmp% echo newline > test
max@oxygen:~/tmp% echo -n "no newline" >> test
max@oxygen:~/tmp% python
Python 2.3.2 (#1, Oct 3 2003, 15:44:45)
[GCC 3.2.2] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> f = file('test')
>>> f.readline()[/color][/color][/color]
'newline\n'[color=blue][color=green][color=darkred]
>>> f.readline()[/color][/color][/color]
'no newline'[color=blue][color=green][color=darkred]
>>> f.readline()[/color][/color][/color]
''

--
Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/
__ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE
/ \ To endure what is unendurable is true endurance.
\__/ (a Japanese proverb)