You should make these categories a list then use a loop to add them to the combobox and declare it as a class function. This way if someone else needs to reuse this list they can simply call <b>UploaderMainApp.CATEGORY_VALUES</b> or something similar.

For example:
<pre>
CATEGORY_VALUES = ['Animals',
                                      'Education',
                                      'Tech']
</pre>

Even better, make the list sorted.

</pre>