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Check to see if files exist and download files within Python

Hello,

I wish to be able to check (in a python script) to see if a file and/or folder already exists on a users hard drive, and if it doesn't exist, download a file from (using the http protocol) online, with the same name that is being checked, into the folder that has been checked.

Also, if the folder that I wish to download into doesn't exist, I would like to create it.

Currently, I am using a very hackish method, as I am on Linux, I am effectively running commands using "os.popen" to create the directory I wish using mkdir (though it cannot check to see if it already exists), and wget to download it into the file.

I wish to make this program/script as cross platform as possible, which means I need to avoid using these, meaning I need to be able to do it within Python.

If there is a way to do it within Python, but only for a specific platform, I am working on Linux, so I need it to be able to at least work on that.

Thank you for your help!

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ghostdog74

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dh-s

ASKER

HI,

"os.path.exists(folder)" to check if the folder/file exists works fine! Thanks.

Unfortuantly, urllib2 does not: [see code snippet]

Do you know where I can get the urllib2 module? As I looked in the Python documentation, and it does exist, but I can't work out where I can get it from to include it with my program/script, or get the user to install it.

Thanks!

>>> import os.urllib2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named urllib2

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dh-s

ASKER

I got the problem I had with the comment below fixed:

I mis-read what you had written, and didn't see that it was a comma, not a full stop (in import os,urllib2). It works when that is fixed, thanks!