read a files particular line

[Frank Grellert]

Hi,
does anybody have an idea how to read a particular line of a file like awk's
awk '{if( NR==12) print $0}' filename (reads lineno 12 of filename)

thanks for your help

Frank Grellert

 

[=?ISO-8859-1?Q?Krist=F3f_Str=F3bl?=]

Hi,

If the file is not too big use:

file("filename").readlines()[11]

Kristóf

 

[Peter L Hansen]

Kristóf Stróbl wrote (top-posting, but I fixed it. You're welcome.):

>> does anybody have an idea how to read a particular line of a file
>> like awk's awk '{if( NR==12) print $0}' filename (reads lineno 12 of
>> filename)

>
If the file is not too big use:

file("filename").readlines()[11]

And if the file is "too big", there's always iterators:

print itertools.islice(open('tempx.txt'), 11, 12).next()

A little more complicated, but avoids reading the entire file
into memory.

-Peter

 

[Miki Tebeka]

Hello Frank,

Hi,
does anybody have an idea how to read a particular line of a file like awk's
awk '{if( NR==12) print $0}' filename (reads lineno 12 of filename)

Check the documentation about the "linecache".

HTH.

 

[Michael Hudson]

Hi,
does anybody have an idea how to read a particular line of a file like awk's
awk '{if( NR==12) print $0}' filename (reads lineno 12 of filename)

for lineno, line in enumerate(open_file):
# lineno starts at 0, though

Cheers,
mwh

 

[Alex Martelli]

does anybody have an idea how to read a particular line of a file like awk's
awk '{if( NR==12) print $0}' filename (reads lineno 12 of filename)

Standard Python library module linecache, which others suggested, is
your best bet. itertools.islice(open('filename'), 12, 13).next() should
also work (after an 'import itertools' of course, since it, too, is a
module in the standard library) and might be faster if you'll never need
to get any other line from that file in the course of your program.


Alex