UPDATE: I used:
Qt Code: 
  1. self.ui.progressbar.setStyleSheet('text-align: center')
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and it works. But I would still like to know how to set the Alignment in the above question.

Also, I have a related question:

Throughout the loading process, I set the progress bar percentage with this code:
Qt Code: 
  1. progressBar.setValue(90)
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with various percentages. Then what is the proper syntax/code to attach this percentage to the "loading files" text to get "Loading files 90%".
the code should look something like:
Qt Code: 
  1. self.ui.progressbar.setFormat('Loading files . . .') + str(the percentage) ?????
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thanks