(self, item)
Check if a column is contained within a `BoundColumns` object.

        *item* can either be a `~.BoundColumn` object, or the name of a column.
Check if a column is contained within a `BoundColumns` object.
Check if a column is contained within a BoundColumns object .
def __contains__(self, item):
        """
        Check if a column is contained within a `BoundColumns` object.

        *item* can either be a `~.BoundColumn` object, or the name of a column.
        """
        if isinstance(item, str):
            return item in self.iternames()
        else:
            # let's assume we were given a column
            return item in self.iterall()
def __contains__ ( self , item ) : if isinstance ( item , str ) : return item in self . iternames ( ) else : # let's assume we were given a column return item in self . iterall ( )