[Courses] [python] No lesson -- open discussion

[Ehud Kaldor]

   -----BEGIN PGP SIGNED MESSAGE-----
   Hash: SHA1
   i know some time went by, but this seems like a good forum to ask:
   is there a good library for 'reading' images? OCR is what comes to
   mind, but I am not sure if this is the right technical term for taking
   an image of text and reading the text off it.
   Thank you, Ehud
   On 08/26/2011 08:38 PM, Akkana Peck wrote:
   > Leslie writes:
   >> I am trying to get good at manipulating files in python. My next
   >> objective: to delete one line of a file. From my researches on the
   web,
   >> it looks like you have to do it indirectly, by writing the lines you
   >> want to keep to a "good" file. Here is an example:
   > [ ... ]
   >> Is this in fact the best way to get rid of a line?
   >
   > Yes. I don't know of any way to insert or delete lines inside files
   > under Linux (whether in Python or any other language).
   >
   > Your example is exactly how I'd do it, with two exceptions. First,
   > there's no need to write the bad line to a second file unless you
   > need to save that as well. You can just say
   > ... if not "goofy" in l:
   > ... goodf.write(l)
   > Of course, if the goal is to keep a record of the bad lines, then I'd
   > create a third file just as you did.
   >
   > Second, instead of
   >>>> lines = inp.readlines()
   >>>> for l in lines:
   >
   > I'd do
   >>>> for l in inp :
   >
   > The difference is that the second version reads one line from the
   > file at a time, while the first reads the whole file in to a list,
   > so Python has to keep the contents of the whole file in memory.
   > Of course that's not a big deal for your small example file, but
   > if you wanted to use it on a really large file, it might make a
   > difference.
   >
   > ...Akkana
   > _______________________________________________
   > Courses mailing list
   > [1]Courses at linuxchix.org
   > [2]http://mailman.linuxchix.org/mailman/listinfo/courses
   -----BEGIN PGP SIGNATURE-----
   Version: GnuPG v1.4.11 (GNU/Linux)
   Comment: Using GnuPG with Mozilla - [3]http://enigmail.mozdev.org/
   iQIcBAEBAgAGBQJObpYTAAoJEAYu2FhJ51YkZ5sP/A7ynZCErW0PvxnedsKxIHx7
   Wy9v7fSJWfFwHjpgibmJUuEb3hx6AewzRVshujoWRnPhML9Dcv5fXySUF1b2rRra
   7+w4AFSGju7KeATZHQColFpkDsAv/RhzE+GH+2SIXu3myzUtyv3WsFx1VK/nTt0+
   aMMV5OllyDx9xOWPlTnYFmhk0g2g7gu4npY4anm4jw+h/9GYPpWXdCukA5cxLHak
   dy6j2FnCSILs6aDnuoEMqIOve986SEnywLGHIektwOjFBZFyPv+Eb/mz51W0HuEE
   xfvcDSogx3IKO3H0AiPF1wd4CK/88HGVxwd23yI93YdIjWdYI1A9D9s282zr/w0P
   55JzpPAObi7f+KE8zgkFCuv3wCLcksBGRIvACr1Ocvs7IaIeRJFyMSDF6GzKZSPC
   1FA56LQI6Mf4bphUxH+pLyy1HTF9VplKL9BknIvvOX5mEMWeaWrtItkaK48ua+5S
   F0Y86AprDdbGeWjvfwgUMiAFh1XjWKagMJS8+hYyqyGpuCvrF3yFE8ieVLiIuiiF
   gBLDGI+vh6RzZSOB2wF2oXD/WekjPsElg9XehYd0FT5+biNkgebXRAGwzTFh4wsq
   5yy8Q2gikGQ6AUJXZ+Y7mQrh9oPJGuYAFPUjXsxqUgEtBK9DwleiXUl8wybMDrxK
   NkszIP6dDsgXAe+XmQw/
   =9yoe
   -----END PGP SIGNATURE-----

References

   1. mailto:Courses at linuxchix.org
   2. http://mailman.linuxchix.org/mailman/listinfo/courses
   3. http://enigmail.mozdev.org/