If an SQL null value<indexterm><primary>null value</primary><secondary

sortas="PL/Python">PL/Python</secondary></indexterm> is passed to a

function, the argument value will appear as <symbol>None</symbol> in

Python. The above function definition will return the wrong answer for null

Python. For example, the function definition of <function>pymax</function>

shown in <xref linkend="plpython-funcs"> will return the wrong answer for null

inputs. We could add <literal>STRICT</literal> to the function definition

to make <productname>PostgreSQL</productname> do something more reasonable:

if a null value is passed, the function will not be called at all,