code: def source(uri, consts):
      ''' read gl code '''
      with open(uri, 'r') as fp:
          content = fp.read()
  
      # feed constant values
      for key, value in consts.items():
          content = content.replace(f"%%{key}%%", str(value))
      return contenf source(uri, consts):
      ''' read gl code '''
      with open(uri, 'r') as fp:
          content = fp.read()
  
      # feed constant values
      for key, value in consts.items():
          content = content.replace(f"%%{key}%%", str(value))
      return content
docs: read gl code