code: def _is_valid_relpath(
          relpath,
          maxdepth=None):
      '''
      Performs basic sanity checks on a relative path.
  
      Requires POSIX-compatible paths (i.e. the kind obtained through
      cp.list_master or other such calls).
  
      Ensures that the path does not contain directory transversal, and
      that it does not exceed a stated maximum depth (if specified).
      '''
      # Check relpath surrounded by slashes, so that `..` can be caught as
      # a path component at the start, end, and in the middle of the path.
      sep, pardir = posixpath.sep, posixpath.pardir
      if sep + pardir + sep in sep + relpath + sep:
          return False
  
      # Check that the relative path's depth does not exceed maxdepth
      if maxdepth is not None:
          path_depth = relpath.strip(sep).count(sep)
          if path_depth > maxdepth:
              return False
  
      return Truf _is_valid_relpath(
          relpath,
          maxdepth=None):
      '''
      Performs basic sanity checks on a relative path.
  
      Requires POSIX-compatible paths (i.e. the kind obtained through
      cp.list_master or other such calls).
  
      Ensures that the path does not contain directory transversal, and
      that it does not exceed a stated maximum depth (if specified).
      '''
      # Check relpath surrounded by slashes, so that `..` can be caught as
      # a path component at the start, end, and in the middle of the path.
      sep, pardir = posixpath.sep, posixpath.pardir
      if sep + pardir + sep in sep + relpath + sep:
          return False
  
      # Check that the relative path's depth does not exceed maxdepth
      if maxdepth is not None:
          path_depth = relpath.strip(sep).count(sep)
          if path_depth > maxdepth:
              return False
  
      return True
docs: Performs basic sanity checks on a relative path.
  
      Requires POSIX-compatible paths (i.e. the kind obtained through
      cp.list_master or other such calls).
  
      Ensures that the path does not contain directory transversal, and
      that it does not exceed a stated maximum depth (if specified).