code: def find_exec_in_path(exec_name):
      
      if "PATH" not in os.environ:
          return
      for p in os.environ["PATH"].split(":"):
          pp = "%s/%s" % (p, exec_name)
          if os.path.exists(pp):
              yield pp
docs: :param str exec_name:
      :return: yields full paths
      :rtype: list[str]