def _get_mainchain(df, invert):
        """Return only main chain atom entries from a DataFrame"""
        if invert:
            mc = df[(df['atom_name'] != 'C') &
                    (df['atom_name'] != 'O') &
                    (df['atom_name'] != 'N') &
                    (df['atom_name'] != 'CA')]
        else:
            mc = df[(df['atom_name'] == 'C') |
                    (df['atom_name'] == 'O') |
                    (df['atom_name'] == 'N') |
                    (df['atom_name'] == 'CA')]
        return mc
def _get_mainchain ( df , invert ) : if invert : mc = df [ ( df [ 'atom_name' ] != 'C' ) & ( df [ 'atom_name' ] != 'O' ) & ( df [ 'atom_name' ] != 'N' ) & ( df [ 'atom_name' ] != 'CA' ) ] else : mc = df [ ( df [ 'atom_name' ] == 'C' ) | ( df [ 'atom_name' ] == 'O' ) | ( df [ 'atom_name' ] == 'N' ) | ( df [ 'atom_name' ] == 'CA' ) ] return mc
Return only main chain atom entries from a DataFrame