For google colab, i recommend use Pydrive.
Your answer can be found in here
How to download file created in Colaboratory workspace?
edit: just change filename.csv to filename.zip or filename.blabla in lines
uploaded = drive.CreateFile({'title': 'filename.csv'})
uploaded.SetContentFile('filename.csv')
why? because this line
uploaded.SetContentFile('filename.csv')
auto set format for you content file, so you don't need to converter it to String or Byte.