parameters: (self)
docstring: Return a list of string keys representing the local
          columns in this :class:`.ForeignKeyConstraint`.
  
          This list is either the original string arguments sent
          to the constructor of the :class:`.ForeignKeyConstraint`,
          or if the constraint has been initialized with :class:`.Column`
          objects, is the string .key of each element.
  
          .. versionadded:: 1.0.0
docstring_summary: Return a list of string keys representing the local
          columns in this :class:`.ForeignKeyConstraint`.
docstring_tokens: Return a list of string keys representing the local columns in this : class : . ForeignKeyConstraint .
function: def column_keys(self):
          """Return a list of string keys representing the local
          columns in this :class:`.ForeignKeyConstraint`.
  
          This list is either the original string arguments sent
          to the constructor of the :class:`.ForeignKeyConstraint`,
          or if the constraint has been initialized with :class:`.Column`
          objects, is the string .key of each element.
  
          .. versionadded:: 1.0.0
  
          """
          if hasattr(self, "parent"):
              return self.columns.keys()
          else:
              return [
                  col.key if isinstance(col, ColumnElement) else str(col)
                  for col in self._pending_colargs
              ]
function_tokens: def column_keys ( self ) : if hasattr ( self , "parent" ) : return self . columns . keys ( ) else : return [ col . key if isinstance ( col , ColumnElement ) else str ( col ) for col in self . _pending_colargs ]