-
Notifications
You must be signed in to change notification settings - Fork 11
Expand file tree
/
Copy pathlambda_magic.html
More file actions
180 lines (166 loc) · 11.4 KB
/
lambda_magic.html
File metadata and controls
180 lines (166 loc) · 11.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
<!DOCTYPE html>
<html class="writer-html5" lang="en" >
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>lambda and keyword Magic — Programming in Python 7.0 documentation</title>
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="../_static/css/theme.css" type="text/css" />
<!--[if lt IE 9]>
<script src="../_static/js/html5shiv.min.js"></script>
<![endif]-->
<script data-url_root="../" id="documentation_options" src="../_static/documentation_options.js"></script>
<script src="../_static/jquery.js"></script>
<script src="../_static/underscore.js"></script>
<script src="../_static/doctools.js"></script>
<script src="../_static/js/theme.js"></script>
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="next" title="Trapezoidal Rule" href="trapezoid.html" />
<link rel="prev" title="Closures and Function Currying" href="../modules/Closures.html" />
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search" style="background: #4b2e83" >
<a href="../index.html">
<img src="../_static/UWPCE_logo_full.png" class="logo" alt="Logo"/>
</a>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
<p class="caption" role="heading"><span class="caption-text">Topics in the Program</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="../topics/01-setting_up/index.html">1. Setting up your Environment</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/02-basic_python/index.html">2. Basic Python</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/03-recursion_booleans/index.html">3. Booleans and Recursion</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/04-sequences_iteration/index.html">4. Sequences and Iteration</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/05-text_handling/index.html">5. Basic Text Handling</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/06-exceptions/index.html">6. Exception Handling</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/07-unit_testing/index.html">7. Unit Testing</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/08-dicts_sets/index.html">8. Dictionaries and Sets</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/09-files/index.html">9. File Handling</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/10-modules_packages/index.html">10. Modules and Packages</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/11-argument_passing/index.html">11. Advanced Argument Passing</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/12-comprehensions/index.html">12. Comprehensions</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/13-intro_oo/index.html">13. Intro to Object Oriented Programing</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/14-magic_methods/index.html">14. Properties and Magic Methods</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/15-subclassing/index.html">15. Subclassing and Inheritance</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/16-multiple_inheritance/index.html">16. Multiple Inheritance</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="../topics/17-functional_programming/index.html">17. Introduction to Functional Programming</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="../modules/OO_vs_functional.html">Object Oriented vs Functional Programming</a></li>
<li class="toctree-l2"><a class="reference internal" href="../modules/Lambda.html">Anonymous Functions: Lambda</a></li>
<li class="toctree-l2"><a class="reference internal" href="../modules/MapFilterReduce.html">Map Filter and Reduce</a></li>
<li class="toctree-l2"><a class="reference internal" href="../modules/IPythonParallel.html">IPython Parallel Quickstart</a></li>
<li class="toctree-l2"><a class="reference internal" href="../modules/Closures.html">Closures and Function Currying</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">lambda and keyword Magic</a></li>
<li class="toctree-l2"><a class="reference internal" href="trapezoid.html">Trapezoidal Rule</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../topics/18-advanced_testing/index.html">18. Advanced Testing</a></li>
<li class="toctree-l1"><a class="reference internal" href="../topics/99-extras/index.html">19. Extra Topics</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" style="background: #4b2e83" >
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="../index.html">Programming in Python</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content style-external-links">
<div role="navigation" aria-label="Page navigation">
<ul class="wy-breadcrumbs">
<li><a href="../index.html" class="icon icon-home"></a> »</li>
<li><a href="../topics/17-functional_programming/index.html"><span class="section-number">17. </span>Introduction to Functional Programming</a> »</li>
<li>lambda and keyword Magic</li>
<li class="wy-breadcrumbs-aside">
<a href="../_sources/exercises/lambda_magic.rst.txt" rel="nofollow"> View page source</a>
</li>
</ul><div class="rst-breadcrumbs-buttons" role="navigation" aria-label="Sequential page navigation">
<a href="../modules/Closures.html" class="btn btn-neutral float-left" title="Closures and Function Currying" accesskey="p"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
<a href="trapezoid.html" class="btn btn-neutral float-right" title="Trapezoidal Rule" accesskey="n">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
</div>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="lambda-and-keyword-magic">
<span id="exercise-lambda-magic"></span><h1>lambda and keyword Magic<a class="headerlink" href="#lambda-and-keyword-magic" title="Permalink to this headline"></a></h1>
<div class="section" id="goals">
<h2>Goals<a class="headerlink" href="#goals" title="Permalink to this headline"></a></h2>
<blockquote>
<div><ul class="simple">
<li><p>A bit of lambda</p></li>
<li><p>functions as objects</p></li>
<li><p>keyword evaluation</p></li>
</ul>
</div></blockquote>
<div class="section" id="task">
<h3>Task<a class="headerlink" href="#task" title="Permalink to this headline"></a></h3>
<p>Write a function that returns a list of n functions,
such that each one, when called, will return the input value,
incremented by an increasing number.</p>
<p>Use a for loop, <code class="docutils literal notranslate"><span class="pre">lambda</span></code>, and a keyword argument</p>
<p><strong>Extra credit:</strong></p>
<p>Do it with a list comprehension, instead of a for loop</p>
<p>Not clear? here’s what you should get…</p>
</div>
<div class="section" id="example-calling-code">
<h3>Example calling code<a class="headerlink" href="#example-calling-code" title="Permalink to this headline"></a></h3>
<div class="highlight-ipython notranslate"><div class="highlight"><pre><span></span><span class="gp">In [96]: </span><span class="n">the_list</span> <span class="o">=</span> <span class="n">function_builder</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<span class="go">### so the_list should contain n functions (callables)</span>
<span class="gp">In [97]: </span><span class="n">the_list</span><span class="p">[</span><span class="mi">0</span><span class="p">](</span><span class="mi">2</span><span class="p">)</span>
<span class="gh">Out[97]: </span><span class="go">2</span>
<span class="go">## the zeroth element of the list is a function that add 0</span>
<span class="go">## to the input, hence called with 2, returns 2</span>
<span class="gp">In [98]: </span><span class="n">the_list</span><span class="p">[</span><span class="mi">1</span><span class="p">](</span><span class="mi">2</span><span class="p">)</span>
<span class="gh">Out[98]: </span><span class="go">3</span>
<span class="go">## the 1st element of the list is a function that adds 1</span>
<span class="go">## to the input value, thus called with 2, returns 3</span>
<span class="gp">In [100]: </span><span class="k">for</span> <span class="n">f</span> <span class="ow">in</span> <span class="n">the_list</span><span class="p">:</span>
<span class="go"> print(f(5))</span>
<span class="gp"> .....:</span>
<span class="go">5</span>
<span class="go">6</span>
<span class="go">7</span>
<span class="go">8</span>
<span class="go">### If you loop through them all, and call them, each one adds one more</span>
<span class="go">to the input, 5... i.e. the nth function in the list adds n to the input.</span>
</pre></div>
</div>
<p>See the test code in <a class="reference download internal" download="" href="../_downloads/6f651cedf7ea27db7a574c8f9167eae0/test_lambda.py"><code class="xref download docutils literal notranslate"><span class="pre">test_lambda.py</span></code></a></p>
</div>
</div>
</div>
</div>
</div>
<footer><div class="rst-footer-buttons" role="navigation" aria-label="Footer">
<a href="../modules/Closures.html" class="btn btn-neutral float-left" title="Closures and Function Currying" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
<a href="trapezoid.html" class="btn btn-neutral float-right" title="Trapezoidal Rule" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
</div>
<hr/>
<div role="contentinfo">
<p>© Copyright 2020, University of Washington, Natasha Aleksandrova, Christopher Barker, Brian Dorsey, Cris Ewing, Christy Heaton, Jon Jacky, Maria McKinley, Andy Miles, Rick Riehle, Joseph Schilz, Joseph Sheedy, Hosung Song. Creative Commons Attribution-ShareAlike 4.0 license.</p>
</div>
Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a
<a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a>
provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script>
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
</body>
</html>