code: def trail_space(self, filters=lambda p: p.ext == ".py"):  # pragma: no cover
          
          self.assert_is_dir_and_exists()
  
          for p in self.select_file(filters):
              try:
                  with open(p.abspath, "rb") as f:
                      lines = list()
                      for line in f:
                          lines.append(line.decode("utf-8").rstrip())
  
                  with open(p.abspath, "wb") as f:
                      f.write("\n".join(lines).encode("utf-8"))
  
              except Exception as e:  # pragma: no cover
                  raise e
docs: Trail white space at end of each line for every ``.py`` file.
  
          **中文文档**
  
          将目录下的所有被选择的文件中行末的空格删除。