code: def get_package_data():
      
      baseline_images = [
          'tests/baseline_images/%s/*' % x
          for x in os.listdir('plotnine/tests/baseline_images')]
      csv_data = ['data/*.csv']
      package_data = {'plotnine': baseline_images + csv_data}
      return package_data
docs: Return package data
  
      For example:
  
          {'': ['*.txt', '*.rst'],
           'hello': ['*.msg']}
  
      means:
          - If any package contains *.txt or *.rst files,
            include them
          - And include any *.msg files found in
            the 'hello' package, too: