How to I lock a file ?

[fowlertrainer]

Hello python-list,

On windows I try with this:

import os
f1=file('a',"w+",os.O_EXCL|os.O_WRONLY)
f1.write("0")
f2=file('a',"w+",os.O_EXCL|os.O_WRONLY)
f2.write("1")
f1.close()
f2.close()

But it is not working...

So how to I lock this file to prevent from next opening ?

Thanx.

 

[Dennis Lee Bieber]

(e-mail address removed) fed this fish to the penguins on Friday 28
November 2003 03:30 am:

On windows I try with this:

import os
f1=file('a',"w+",os.O_EXCL|os.O_WRONLY)

But it is not working...

So how to I lock this file to prevent from next opening ?

First step: read the documentation for file() (section 2.1 of the
Library reference)

file(filename[, mode[, bufsize]])

Does anything in that definition imply being able to set locking?

Hint, anything that is a builtin to Python is unlikely to be using
constants defined in an imported module.

Second step: read the documentation for the os module (6.1.3 in my
copy).

open(file, flags[, mode])


In short, you are trying to mix flags from two separate types of file
operations.

--

 

[Miki Tebeka]

Hello,

f1=file('a',"w+",os.O_EXCL|os.O_WRONLY)

Have a look at the documentation, the 3'rd parameter to "file" is the buffer size.

So how to I lock this file to prevent from next opening ?

Use os.open or the win32all package (with CreateFile).

HTH.
Miki