<!DOCTYPE qhelp PUBLIC

"-//Semmle//qhelp//EN"

"qhelp.dtd">

<qhelp>

<overview>

<p>

A common pattern for functions returning multiple arguments is to return a

single tuple containing said arguments. If the function has multiple return

points, care must be taken to ensure that the tuples returned have the same

length.

</p>

</overview>

<recommendation>

<p>Ensure that the function returns tuples of similar lengths.</p>

</recommendation>

<example>

<p>

In this example, the <code>sum_length_product1</code> function

simultaneously calculates the sum, length, and product of the values in the

given list. For empty lists, however, the returned tuple only contains the

sum and length of the list. In <code>sum_length_product2</code> this error

has been corrected.

</p>

<sample src="ReturnConsistentTupleSizes.py" />

</example>

<references>

<li>Python Language Reference: <a href="http://docs.python.org/2/reference/compound_stmts.html#function">Function definitions</a>.

</li>

</references>

</qhelp>