I need my compiled Python Mac app to accept a file as a parameter

[Oethen]

I compiled my Python script to a Mac app. I need to have accept a file as a parameter (drag and drop onto app). I know I need to edit the info.plist and I have tried (code below) but it's not working. When I pass the file as a parameter in the Terminal to the .py script, it works so I know it's not my Python code. If anyone can lend a hand, that would be great! Thanks!

<key>CFBundleTypeExtensions</key>
<array>
   <string>pdf</string>
</array>
<key>CFBundleTypeIconFile</key>
<string>generic.icns</string>
<key>CFBundleTypeName</key>
<string>IMG Disk Image</string>
<key>CFBundleTypeRole</key>
<string>Viewer</string>