AssertOnTuple.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>
<overview>
<p>When you define an <code>assert</code> statement to test a tuple the test 
will either always succeed (if the tuple is non-empty) or always 
fail (if the tuple is empty).</p>

<p>This error usually occurs when the programmer writes <code>
assert (condition, message)
</code>
instead of the correct form<code>
assert condition, message
</code>
</p>

</overview>
<recommendation>

<p>Review the code and determine the purpose of the <code>assert</code> statement:</p>
<ul>
<li>
If the "tuple" has been created in error, then remove the parentheses and correct the statement</li>
<li>If validation of a tuple is intended, then you should define an <code>assert</code> statement 
for each element of the tuple.</li>
</ul>

</recommendation>
<example>
<p>The statement <code>assert (xxx, yyy)</code> attempts to test a "tuple" <code>(xxx, yyy)</code>. 
The original intention may be any of the alternatives listed below:</p>
<sample src="AssertOnTuple.py" />

<p>If you want to define a validity check on the values of a tuple then these must be tested 
individually.</p>

</example>
<references>

<li>Python Language Reference: <a href="http://docs.python.org/2.7/reference/simple_stmts.html#the-assert-statement">The assert statement</a>.</li>
<li>Tutorials Point: <a href="http://www.tutorialspoint.com/python/assertions_in_python.htm">Assertions in Python</a>.</li>


</references>
</qhelp>