file open default location

[T. Crane]

Hi,

How is the default path chosen in this instance:

myFile = file('test.txt','w')

Here I'm opening/creating a file but I have not specified the exact path, so
how does Python determine where to 'put' this file? More to the point, how
do I change what the default path is? Right now it's a networked drive that
should not be getting my Python clutter.

Interestingly, this network drive is also where I can find my _ipython
folder from my ipython install as well as my .matplotlib folder. Can anyone
tell me how to change where these folders and files go by default?

thanks for any help,
trevis

 

[kyosohma]

Hi,

How is the default path chosen in this instance:

myFile = file('test.txt','w')

Here I'm opening/creating a file but I have not specified the exact path, so
how does Python determine where to 'put' this file? More to the point, how
do I change what the default path is? Right now it's a networked drive that
should not be getting my Python clutter.

Interestingly, this network drive is also where I can find my _ipython
folder from my ipython install as well as my .matplotlib folder. Can anyone
tell me how to change where these folders and files go by default?

thanks for any help,
trevis

When you don't specify where you want to save a file, it saves the
file to the directory the script itself is run from. As far as I know,
you have to specify where you want the file saved if you don't want it
with the script.py

Mike

 

[T. Crane]

When you don't specify where you want to save a file, it saves the
file to the directory the script itself is run from. As far as I know,
you have to specify where you want the file saved if you don't want it
with the script.py

Unfortunately, this is not the case. My module's path is this:

C:\documents and setting\t_crane\my documents\python modules\script.py

Python is in the directory C:\Python25

The file is being saved in this path:

K:\myFile.txt (this is the networked drive mentioned above)

As an aside, I forgot to mention above that I'm using Windows XP. Any other
ideas or possible reasons that it would not choose my script location as the
default location to save something?

thanks,
trevis

 

[Richard Brodie]

As an aside, I forgot to mention above that I'm using Windows XP. Any other ideas or
possible reasons that it would not choose my script location as the default location to
save something?

If you open a DOS window and run Python from there, it will write the files
in whatever directory you were in when you typed the command.

If you are running Python directly from Windows, or from an IDE, it's up
to the OS or the IDE to decide what your default directory is. Often it
will be the home directory from your user profile.

 

[T. Crane]

As an aside, I forgot to mention above that I'm using Windows XP. Any

If you open a DOS window and run Python from there, it will write the
files
in whatever directory you were in when you typed the command.

If you are running Python directly from Windows, or from an IDE, it's up
to the OS or the IDE to decide what your default directory is. Often it
will be the home directory from your user profile.

I'm using ipython and running everything from there. On my wife's laptop
the default save location is the home directory of her user profile, but on
my work computer this is not the case. Therefore I assume that there's some
setting somewhere that's causing ipython to send stuff to such a weird
location.

trevis

 

[Tim Golden]

myFile = file('test.txt','w')

Here I'm opening/creating a file but I have not specified the exact path, so
how does Python determine where to 'put' this file? More to the point, how
do I change what the default path is? Right now it's a networked drive that
should not be getting my Python clutter.

Python doesn't choose anything. Whatever your
Operating System deems the current drive when
you start Python is the one which will contain
any other unqualified files. You can find out
what it is by running a script which just does:

import os
print os.getcwd ()

and you can change it by doing this:

import os
os.chdir ("new-path-of-my-choosing")

Interestingly, this network drive is also where I can find my _ipython
folder from my ipython install as well as my .matplotlib folder. Can anyone
tell me how to change where these folders and files go by default?

Different question. (And, I'm afraid, a more complicated one). You
haven't said, but I'm going to guess you're running on Windows,
not least because any *nix setup I know of will place the user in
a well-known "Home" directory (typically /home/username).

The trouble is that applications like ipython, and maybe
matplotlib, were developed under *nix where you can rely
on getting hold of a user's "Home" directory either by
expanding the "~" shell variable -- or whatever it's called --
or by examining the HOME shell variable. Windows doesn't
traditionally have either of these things, and has over
the years had several locations with legitimate claim to
be "Home".

Python's own os.expanduser, for example, uses this approach:
"""
On Windows, only "~" is supported; it is replaced by the
environment variable HOME or by a combination of
HOMEDRIVE and HOMEPATH
"""

I think IPython now uses expandvar. Maybe it always did;
I've an idea its current behaviour was a more recent
addition to Python under Windows. But IPython used to
fall back to C:\ if it couldn't do anything else.
Don't know about matplotlib. You'll need to check the
docs (or the source).

TJG

 

[kyosohma]

If you open a DOS window and run Python from there, it will write the files
in whatever directory you were in when you typed the command.

If you are running Python directly from Windows, or from an IDE, it's up
to the OS or the IDE to decide what your default directory is. Often it
will be the home directory from your user profile.

Oops. My bad. I didn't know that the IDE behaved differently than the
DOS window.

Mike

 

[Gabriel Genellina]

Oops. My bad. I didn't know that the IDE behaved differently than the
DOS window.

You almost certainly use a shortcut to open the program, either in your
desktop or Start menu. Right click on it, choose Properties, Shortcut tab,
and see what it says for "Startup Directory" (or something like that).
That will be the original "current directory" when the program starts; but
it may be changed afterwards.

 

[T. Crane]

You almost certainly use a shortcut to open the program, either in your
desktop or Start menu. Right click on it, choose Properties, Shortcut tab,
and see what it says for "Startup Directory" (or something like that).
That will be the original "current directory" when the program starts; but
it may be changed afterwards.

AHA! thank you I checked the shortcut and NO start up directory was
specified, which caused it for some reason to choose the K: drive. After
specifying the startup directory it works as I want it to.

thanks,
trevis