Linux > python > file-I/O ?

Steve Horsley steve.horsley at gmail.com
Sun Dec 25 19:32:05 CET 2005


news at absamail.co.za wrote:
> I've just started to test/learn python.
> I've got Linux > mandrake9 > python  & documentation.
> What I'll initially want to be doing needs file I/O, so I
> wanted to confirm file I/O early in my tests.
> 
> Following the examples :
>>>> f=open('/tmp/workfile', 'w')
>>>> print f
> <open file '/tmp/workfile', mode 'w' at 80a0960>   <-- OK
> 
> But:
>>>> f.read(size)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
> NameError: name 'size' is not defined  <-- ?? Obj-method unknown ??
> 
> 
> What's wrong ?
> 

size should be a number of bytes to read. E.g.:
     f.read(1000)
would read 1000 bytes. The size is optional:
     f.read()
would read the entire file in one hit. Beware doing this on huge 
files that could run you out of memory.


> I read:   "The set of such modules is a configuration 
> option which also depends on the underlying platform."
> My documenation refers also to Mac & Win installations.
> Is there a linux > python NewsGroup ?
> 
Not that I know of. Python is much the same whatever platform it 
is on. The problem you see above would be exactly the same on 
Linux, Windows or any other O/S.

Just remember to say what O/S when you post problems, just in 
case it's relevant.

Steve



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