tools/src/nas,5.n2.os.2/lib/python/html/python/lib/node164.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<link rel="STYLESHEET" href="lib.css" type='text/css' />
<link rel="SHORTCUT ICON" href="../icons/pyfav.png" type="image/png" />
<link rel='start' href='../index.html' title='Python Documentation Index' />
<link rel="first" href="lib.html" title='Python Library Reference' />
<link rel='contents' href='contents.html' title="Contents" />
<link rel='index' href='genindex.html' title='Index' />
<link rel='last' href='about.html' title='About this document...' />
<link rel='help' href='about.html' title='About this document...' />
<link rel="next" href="organizing-tests.html" />
<link rel="prev" href="module-unittest.html" />
<link rel="parent" href="module-unittest.html" />
<link rel="next" href="organizing-tests.html" />
<meta name='aesop' content='information' />
<title>5.3.1 Basic example </title>
</head>
<body>
<DIV CLASS="navigation">
<div id='top-navigation-panel' xml:id='top-navigation-panel'>
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td class='online-navigation'><a rel="prev" title="5.3 unittest  "
  href="module-unittest.html"><img src='../icons/previous.png'
  border='0' height='32'  alt='Previous Page' width='32' /></A></td>
<td class='online-navigation'><a rel="parent" title="5.3 unittest  "
  href="module-unittest.html"><img src='../icons/up.png'
  border='0' height='32'  alt='Up One Level' width='32' /></A></td>
<td class='online-navigation'><a rel="next" title="5.3.2 Organizing test code"
  href="organizing-tests.html"><img src='../icons/next.png'
  border='0' height='32'  alt='Next Page' width='32' /></A></td>
<td align="center" width="100%">Python Library Reference</td>
<td class='online-navigation'><a rel="contents" title="Table of Contents"
  href="contents.html"><img src='../icons/contents.png'
  border='0' height='32'  alt='Contents' width='32' /></A></td>
<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
  border='0' height='32'  alt='Module Index' width='32' /></a></td>
<td class='online-navigation'><a rel="index" title="Index"
  href="genindex.html"><img src='../icons/index.png'
  border='0' height='32'  alt='Index' width='32' /></A></td>
</tr></table>
<div class='online-navigation'>
<b class="navlabel">Previous:</b>
<a class="sectref" rel="prev" href="module-unittest.html">5.3 unittest  </A>
<b class="navlabel">Up:</b>
<a class="sectref" rel="parent" href="module-unittest.html">5.3 unittest  </A>
<b class="navlabel">Next:</b>
<a class="sectref" rel="next" href="organizing-tests.html">5.3.2 Organizing test code</A>
</div>
<hr /></div>
</DIV>
<!--End of Navigation Panel-->

<H2><A NAME="SECTION007310000000000000000"></A><A NAME="minimal-example"></A>
<BR>
5.3.1 Basic example
</H2>

<P>
The <tt class="module">unittest</tt> module provides a rich set of tools for
constructing and running tests.  This section demonstrates that a
small subset of the tools suffice to meet the needs of most users.

<P>
Here is a short script to test three functions from the
<tt class="module"><a href="module-random.html">random</a></tt> module:

<P>
<div class="verbatim"><pre>
import random
import unittest

class TestSequenceFunctions(unittest.TestCase):

    def setUp(self):
        self.seq = range(10)

    def testshuffle(self):
        # make sure the shuffled sequence does not lose any elements
        random.shuffle(self.seq)
        self.seq.sort()
        self.assertEqual(self.seq, range(10))

    def testchoice(self):
        element = random.choice(self.seq)
        self.assert_(element in self.seq)

    def testsample(self):
        self.assertRaises(ValueError, random.sample, self.seq, 20)
        for element in random.sample(self.seq, 5):
            self.assert_(element in self.seq)

if __name__ == '__main__':
    unittest.main()
</pre></div>

<P>
A testcase is created by subclassing <tt class="class">unittest.TestCase</tt>.
The three individual tests are defined with methods whose names start with
the letters "<tt class="samp">test</tt>".  This naming convention informs the test runner
about which methods represent tests.

<P>
The crux of each test is a call to <tt class="method">assertEqual()</tt> to
check for an expected result; <tt class="method">assert_()</tt> to verify a condition;
or <tt class="method">assertRaises()</tt> to verify that an expected exception gets
raised.  These methods are used instead of the <tt class="keyword">assert</tt> statement
so the test runner can accumulate all test results and produce a report.

<P>
When a <tt class="method">setUp()</tt> method is defined, the test runner will run that
method prior to each test.  Likewise, if a <tt class="method">tearDown()</tt> method is
defined, the test runner will invoke that method after each test.  In the
example, <tt class="method">setUp()</tt> was used to create a fresh sequence for each test.

<P>
The final block shows a simple way to run the tests.
<tt class="function">unittest.main()</tt> provides a command line interface to the
test script.  When run from the command line, the above script
produces an output that looks like this:

<P>
<div class="verbatim"><pre>
...
----------------------------------------------------------------------
Ran 3 tests in 0.000s

OK
</pre></div>

<P>
Instead of <tt class="function">unittest.main()</tt>, there are other ways to run the tests
with a finer level of control, less terse output, and no requirement to be
run from the command line.  For example, the last two lines may be replaced
with:

<P>
<div class="verbatim"><pre>
suite = unittest.makeSuite(TestSequenceFunctions)
unittest.TextTestRunner(verbosity=2).run(suite)
</pre></div>

<P>
Running the revised script from the interpreter or another script
produces the following output:

<P>
<div class="verbatim"><pre>
testchoice (__main__.TestSequenceFunctions) ... ok
testsample (__main__.TestSequenceFunctions) ... ok
testshuffle (__main__.TestSequenceFunctions) ... ok

----------------------------------------------------------------------
Ran 3 tests in 0.110s

OK
</pre></div>

<P>
The above examples show the most commonly used <tt class="module">unittest</tt> features
which are sufficient to meet many everyday testing needs.  The remainder
of the documentation explores the full feature set from first principles.

<P>

<DIV CLASS="navigation">
<div class='online-navigation'>
<p></p><hr />
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td class='online-navigation'><a rel="prev" title="5.3 unittest  "
  href="module-unittest.html"><img src='../icons/previous.png'
  border='0' height='32'  alt='Previous Page' width='32' /></A></td>
<td class='online-navigation'><a rel="parent" title="5.3 unittest  "
  href="module-unittest.html"><img src='../icons/up.png'
  border='0' height='32'  alt='Up One Level' width='32' /></A></td>
<td class='online-navigation'><a rel="next" title="5.3.2 Organizing test code"
  href="organizing-tests.html"><img src='../icons/next.png'
  border='0' height='32'  alt='Next Page' width='32' /></A></td>
<td align="center" width="100%">Python Library Reference</td>
<td class='online-navigation'><a rel="contents" title="Table of Contents"
  href="contents.html"><img src='../icons/contents.png'
  border='0' height='32'  alt='Contents' width='32' /></A></td>
<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
  border='0' height='32'  alt='Module Index' width='32' /></a></td>
<td class='online-navigation'><a rel="index" title="Index"
  href="genindex.html"><img src='../icons/index.png'
  border='0' height='32'  alt='Index' width='32' /></A></td>
</tr></table>
<div class='online-navigation'>
<b class="navlabel">Previous:</b>
<a class="sectref" rel="prev" href="module-unittest.html">5.3 unittest  </A>
<b class="navlabel">Up:</b>
<a class="sectref" rel="parent" href="module-unittest.html">5.3 unittest  </A>
<b class="navlabel">Next:</b>
<a class="sectref" rel="next" href="organizing-tests.html">5.3.2 Organizing test code</A>
</div>
</div>
<hr />
<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
</DIV>
<!--End of Navigation Panel-->
<ADDRESS>
See <i><a href="about.html">About this document...</a></i> for information on suggesting changes.
</ADDRESS>
</BODY>
</HTML>