code: def find_data(path, warn=True):
      
      full_path = os.path.join(get_data_dir(), path)
      if warn and not os.path.isfile(full_path):
          for package in PACKAGES:
              if path == package.path:
                  log.warn('%s doesn\'t exist. Run `cde data download` to get it.' % path)
                  break
      return full_path
docs: Return the absolute path to a data file within the data directory.