UndefinedGlobal.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>

<overview>
<p>This global variable may not be defined.
If this code is executed and the variable is undefined then a <code>NameError</code> will occur.
</p>

</overview>
<recommendation>

<p>Check that the name of the global variable is not a typographic error. If the name is correct
then define the variable or import the module that defines the function or method.</p>

<p>If it is expected this variable will be initialized from another module before it is used, then the <code>NameError</code> may not occur.
Nonetheless, the code will be more robust and clearer if the variable is set to a default value in its own module.
</p>

</recommendation>
<example>
<p>The following examples show two different examples of undefined "global variables".</p>

<sample src="UndefinedGlobal.py" />


</example>
<references>

<li>Python Standard Library: <a href="https://docs.python.org/library/exceptions.html#exceptions.NameError">NameError</a>.</li>
<li>The Python Tutorial: <a href="http://docs.python.org/2/tutorial/modules.html">Modules</a>.</li>


</references>
</qhelp>