File object question

[S. D. Rose]

Hello all.
If I read a binary file:

file = open('c:\\logo. gif', 'rw'') # Read from FS as one way to get the
object, d/l from website another...
file.read()

is there anyway I can determine the 'size' of the object file? (Without
going to the filesystem and reading the filesize from the directory ...)

Thanks!

[mrmakent@cox.net]

Re: File object question

See http://www.python.org/doc/2.4.2/lib/os-file-dir.html for the 'stat'
function

import os
os.stat(path).s t_size

This will return the size in bytes of the file designated by 'path'.

[Kent Johnson]

Re: File object question

S. D. Rose wrote:[color=blue]
> Hello all.
> If I read a binary file:
>
> file = open('c:\\logo. gif', 'rw'') # Read from FS as one way to get the
> object, d/l from website another...
> file.read()
>
> is there anyway I can determine the 'size' of the object file? (Without
> going to the filesystem and reading the filesize from the directory ...)[/color]

Once you have read the data you can get the size of that:
d = file.read()
print len(d)

Is that what you mean? Otherwise I don't know how you can get the size of a file without
asking the filesystem...

Kent

[S. D. Rose]

Re: File object question

Yes, len() will do what I want. I didn't realize it would work with binary,
I thought it was good only for variables, lists, etc.

Thanks!
-Dave

"Kent Johnson" <kent@kentsjohn son.com> wrote in message
news:43ab3f2c_1 @newspeer2.tds. net...[color=blue]
> S. D. Rose wrote:[color=green]
> > Hello all.
> > If I read a binary file:
> >
> > file = open('c:\\logo. gif', 'rw'') # Read from FS as one way to get the
> > object, d/l from website another...
> > file.read()
> >
> > is there anyway I can determine the 'size' of the object file? (Without
> > going to the filesystem and reading the filesize from the directory ...)[/color]
>
> Once you have read the data you can get the size of that:
> d = file.read()
> print len(d)
>
> Is that what you mean? Otherwise I don't know how you can get the size of[/color]
a file without[color=blue]
> asking the filesystem...
>
> Kent
> --
> http://mail.python.org/mailman/listinfo/python-list
>[/color]

[Ben Hutchings]

Re: File object question

S. D. Rose <s_david_rose@h otmail.com> wrote:[color=blue]
> "Kent Johnson" <kent@kentsjohn son.com> wrote in message
> news:43ab3f2c_1 @newspeer2.tds. net...[color=green]
>> S. D. Rose wrote:[color=darkred]
>> > Hello all.
>> > If I read a binary file:
>> >
>> > file = open('c:\\logo. gif', 'rw'') # Read from FS as one way to get the
>> > object, d/l from website another...
>> > file.read()
>> >
>> > is there anyway I can determine the 'size' of the object file? (Without
>> > going to the filesystem and reading the filesize from the directory ...)[/color]
>>
>> Once you have read the data you can get the size of that:
>> d = file.read()
>> print len(d)
>>
>> Is that what you mean? Otherwise I don't know how you can get the size of
>> a file without
>> asking the filesystem...[/color]
>
> Yes, len() will do what I want. I didn't realize it would work with binary,[/color]

The read() function returns a string (object of type str), whether the
file was opened in binary or text mode. Such objects are really a
series of bytes which may or may not represent text in some encoding.
(By contrast, objects of type unicode definitely do represent text in
some Unicode encoding.)
[color=blue]
> I thought it was good only for variables, lists, etc.[/color]

Variables? Do you mean tuples? len() works with any kind of sequence,
and strings behave as a sequence of 1-byte strings.

--
Ben Hutchings
It is easier to write an incorrect program than to understand a correct one.