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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+BEAMER_FRAME_LEVEL: 1
#+BEAMER_HEADER_EXTRA: \usetheme{Warsaw}\usecolortheme{default}\useoutertheme{infolines}\setbeamercovered{transparent}
#+COLUMNS: %45ITEM %10BEAMER_env(Env) %10BEAMER_envargs(Env Args) %4BEAMER_col(Col) %8BEAMER_extra(Extra)
#+PROPERTY: BEAMER_col_ALL 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 :ETC
#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+LaTeX_HEADER: \usepackage[english]{babel} \usepackage{ae,aecompl}
#+LaTeX_HEADER: \usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet}
#+LaTeX_HEADER: \usepackage{listings}
#+LaTeX_HEADER:\lstset{language=Python, basicstyle=\ttfamily\bfseries,
#+LaTeX_HEADER: commentstyle=\color{red}\itshape, stringstyle=\color{red},
#+LaTeX_HEADER: showstringspaces=false, keywordstyle=\color{blue}\bfseries}
#+TITLE:
#+AUTHOR: FOSSEE
#+EMAIL:
#+DATE:
#+DESCRIPTION:
#+KEYWORDS:
#+LANGUAGE: en
#+OPTIONS: H:3 num:nil toc:nil \n:nil @:t ::t |:t ^:t -:t f:t *:t <:t
#+OPTIONS: TeX:t LaTeX:nil skip:nil d:nil todo:nil pri:nil tags:not-in-toc
*
#+begin_latex
\begin{center}
\vspace{12pt}
\textcolor{blue}{\huge Testing and Debugging}
\end{center}
\vspace{18pt}
\begin{center}
\vspace{10pt}
\includegraphics[scale=0.95]{../images/fossee-logo.png}\\
\vspace{5pt}
\scriptsize Developed by FOSSEE Team, IIT-Bombay. \\
\scriptsize Funded by National Mission on Education through ICT\\
\scriptsize MHRD,Govt. of India\\
\includegraphics[scale=0.30]{../images/iitb-logo.png}\\
\end{center}
#+end_latex
* Objectives
At the end of the tutorial, you will be able to,
- Understand what is software testing.
- Test simple functions for their functionality.
- Automate tests.
- Understand the need for coding style
- Learn some of the standards followed by the Python Community.
- Handle Errors and Exceptions.
* Pre-requisite
Spoken tutorial on -
- Getting started with functions.
- Advanced Features of functions.
* gcd function
- Create gcd.py file with:
#+begin_src python
def gcd(a, b):
if a % b == 0:
return b
return gcd(b, a%b)
#+end_src python
* Test for gcd.py
- Edit gcd.py file
#+begin_src python
def gcd(a, b):
if b == 0:
return a
return gcd(b, a%b)
if __name__=='__main__':
result = gcd(48, 64)
if result != 16:
print "Test failed"
print "Test Passed"
#+end_src
* Idiom
if \_\_name\_\_ == '\_\_main\_\_':
* Exercise 1
- Write code for gcd and write tests for it
* Structure of file
| 12 | 28 | 4 |
| 18 | 36 | 18 |
| 4678 | 39763 | 2339 |
* Automating tests
#+begin_src python
if __name__ == '__main__':
for line in open('lcmtestcases.txt'):
numbers = line.split()
x = int(numbers[0])
y = int(numbers[1])
result = int(numbers[2])
if lcm(x, y) != result:
print "Failed lcm test for", x, y
else:
print "Test passed"
#+end_src
* Exercise 2
- For the same inputs as gcd write automated tests for LCM.
* Solution 2
#+begin_src python
def gcd(a, b):
if a % b == 0:
return b
return gcd(b, a%b)
def lcm(a, b):
return (a * b) / gcd(a, b)
if __name__ == '__main__':
for line in open('lcmtestcases.txt'):
numbers = line.split()
x = int(numbers[0])
y = int(numbers[1])
result = int(numbers[2])
if lcm(x, y) != result:
print "Failed lcm test for", x, y
else:
print "Test passed", result
#+end_src
* Meaning full names
#+begin_src python
amount = 12.68
denom = 0.05
nCoins = round(amount / denom)
rAmount = nCoins * denom
#+end_src
* Code style
- Four Space Indentation
- 79 character limit on a line
- Funtions should be seperated by
blank line
- Use Docstring
- White space around operators
- l = 32 % 4
* Exercise 3
- Give meaningful names to the variables in following
code
- c = a / b
* Solution 3
#+begin_src python
quotient = dividend / divisor
#+end_src
* Using idb
#+begin_latex
\small
\begin{lstlisting}
In []: import mymodule
In []: mymodule.test()
---------------------------------------------
NameError Traceback (most recent call last)
<ipython console> in <module>()
mymodule.py in test()
1 def test():
2 total=1+1
----> 3 print spam
NameError: global name 'spam' is not defined
In []: %debug
> mymodule.py(2)test()
0 print spam
ipdb> total
2
\end{lstlisting}
#+end_latex
* Summary
In this tutorial, we have learnt to,
- Create simple tests for a function.
- Automate tests using many predefined test cases.
- Use the python coding standards.
- Differentiate between syntax error and exception.
- Handle exception using ``try'' and ``except''.
- Use ``%debug'' for debugging on ipython.
* Evaluation
1. What is proper indentation for python code according to style guidelines?
- two space identation
- three space identation
- four Space Indentation
- no Indentation
2. How do you start the debugger on ipython?
- debug
- %debug
- %debugger
- start debugger
3. What is the idiom used for running python scripts in a standalone manner?
* Solutions
1. Four Space Indentation
2. %debug
3. if \_\_name\_\_ == '\_\_main\_\_':
*
#+begin_latex
\begin{block}{}
\begin{center}
\textcolor{blue}{\Large THANK YOU!}
\end{center}
\end{block}
\begin{block}{}
\begin{center}
For more Information, visit our website\\
\url{http://fossee.in/}
\end{center}
\end{block}
#+end_latex
|
