Python get selected text

How would I, using Python "catch" text that a user has selecting in, for example, a web browser? The script would idle 开发者_高级运维in the background, and when a certain key combination is pressed, it "gets" the text the user has selected. Think copy & paste, only it copies to my application instead of a clipboard.

Thanks! I'd like to point out that this will be for Mac.

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1. Install xsel

   sudo apt-get install xclip xsel -y
   

2. Save this as get-selected.py

   import os
   print(os.popen('xsel').read())
   

3. Select text

4. Run

   python get-selected.py