PoojaMoolya: Created page with "{| border=1 |'''Time''' |'''Narration''' |- |00:01 |Welcome to the spoken tutorial on '''Testing and debugging.''' |- |00:06 |In this tutorial, you will, Understand what is..."

2019-06-10T11:53:30Z

Created page with "{| border=1 |'''Time''' |'''Narration''' |- |00:01 |Welcome to the spoken tutorial on '''Testing and debugging.''' |- |00:06 |In this tutorial, you will, Understand what is..."

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{| border=1
|'''Time'''
|'''Narration'''

|-
|00:01
|Welcome to the spoken tutorial on '''Testing and debugging.'''

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|00:06
|In this tutorial, you will, Understand what is '''software testing '''

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|00:11
|Test simple '''functions''' for their '''functionality '''

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|00:15
|'''Automate tests '''

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|00:17
|Understand the need for '''coding style''' and Learn some of the '''standards''' followed by the '''Python Community'''

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|00:25
|To record this tutorial, I am using

'''Ubuntu Linux 16.04''' operating system

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|00:32
|'''Python 3.4.3 '''

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|00:35
|'''IPython 5.1.0''' and '''Gedit text editor'''

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|00:42
|To practise this tutorial, you should know how to use '''functions.'''

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|00:48
|If not, see the relevant '''Python''' tutorials on this website.

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|00:53
|First we will learn about software testing.

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|00:57
| '''Software testing''' is the process to evaluate the functionality of a software or a '''program.'''

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|01:04
|It helps to find whether the program met the specified requirements or not.

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|01:10
|It ensures a defect free program so that we will get a quality program.

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|01:16
|All the codes used in this tutorial are available in the '''Code Files''' link of this tutorial.

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|01:23
|You should download in the current working directory and use them.

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|01:28
|Open any text editor and type the following code.

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|01:33
|This is a simple '''function''' to calculate '''gcd''' of two numbers.

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|01:38
|We need a set of '''inputs''' for the variable a and b.

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|01:43
|Save the file as '''find''' underscore '''gcd.py''' in the current '''working directory.'''

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|01:50
|Next we will open the file '''test''' underscore '''gcd.py.'''

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|01:56
|Let our test case be 48 and 64 as '''a''' and '''b. '''

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|02:02
|For this test case we know that the GCD is 16. So that is the expected '''output.'''

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|02:11
|Let us now run the '''script''' and '''test''' our '''code. '''

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|02:15
|Open the '''terminal''' and type '''python3 test''' underscore '''gcd.py'''

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|02:24
|We get the '''output''' as '''Test Passed''' which means our '''code''' is correct.

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|02:30
|But there can be a number of cases where the '''gcd function''' might break.

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|02:36
|So, to check where our code is breaking we should run many tests.

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|02:42
| This is where the concept of automating tests comes in.

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|02:46
|Let us first try and automate tests on the '''gcd function. '''

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|02:51
|Open the file '''textcases.txt''' where the various testing parameters are given.

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|02:58
|The structure of the file will have two '''input parameters. '''

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|03:03
|The third '''parameter''' is the correct '''output result'''. We have separated the elements by a space.

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|03:11
|Next let us open the file '''automate''' underscore '''test''' underscore '''gcd.py'''

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|03:18
|First we need '''import gcd function''' from '''find''' underscore '''gcd''' in order to use it for testing.

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|03:26
|Next the '''testcases.txt''' file is read line by line.

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|03:32
|The first two '''input parameters''' are assigned to the variables '''x''' and '''y.'''

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|03:38
|The third '''parameter''' which is the correct '''output''' value is assigned to the variable '''result.'''

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|03:44
|We check whether the value returned by the '''gcd function''' is equal to the value in the '''variable result.'''

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|03:52
|Finally it prints the message accordingly.

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|03:56
|In the '''terminal''', type '''python3 automate''' underscore '''test''' underscore '''gcd.py'''

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|04:05
|As you can see, all the three '''test cases''' in '''testcases.txt''' are passed.

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|04:12
|The value calculated by the '''gcd function''' is equal to the output value provided in the '''testcases.txt.'''

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|04:20
|Pause the video. Try this exercise and then resume the video.

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|04:26
|For the same inputs as '''gcd''' write '''automated tests''' for '''LCM. '''

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|04:33
|Use the data from the file '''lcmtestcases.txt'''

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|04:38
|Switch to the '''terminal''' for the solution.

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|04:42
|Let us see the code to calculate '''lcd''' of two numbers.

The file name is '''find''' underscore '''lcm.py'''

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|04:52
|This is the data file for the '''lcm''' test cases.

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|04:57
|This file name is '''lcmtestcases.txt'''

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|05:02
|Note that both these files should be in the current '''working directory.'''

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|05:07
|Let us now run the '''script''' and '''test''' our '''code.'''

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|05:11
|Type '''python3 find''' underscore '''lcm.py'''

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|05:17
|Here, the third test case failed. Because the corresponding input in '''lcmtestcases.txt''' is incorrect.

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|05:26
|This is to check the behavior of the program on incorrect conditions.

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|05:32
|A good '''program''' should be '''readable'''. So others can extend and improve it.

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|05:39
|'''Code''' is read more often than it is written.

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|05:43
|We choose a name so that it becomes easier to understand its usage.

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|05:49
| As we can see in the example, it is very easy to understand what the '''code''' is doing.

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|05:55
|Proper naming helps so much in understanding the '''code.'''

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|06:00
|Also one should keep in mind the following things while writing a '''code''' in Python.

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|06:06
| '''Four Space Indentation '''

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|06:09
|79 characters limit on a line

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|06:13
|'''Functions''' and '''methods''' should be separated with two blank lines.

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|06:18
| Use '''Docstring''' to document a specific segment of code.

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|06:23
| Use '''whitespace''' around '''operators''' and after punctuations.

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|06:28
|This brings us to the end of this tutorial. Let us summarize.

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|06:34
|In this tutorial, we have learnt to,

Create simple '''tests''' for a '''function '''

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|06:40
|'''Automate tests''' using many '''predefined test cases''' and Use '''python coding standards.'''

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|06:49
|Here is a self assessment question for you to solve

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|06:53
|What is the proper indentation for '''python code''' according to the '''style''' guidelines?

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|06:59
|And the answer, Four Space Indentation is required for writing a python code according to the style guidelines.

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|07:08
|Please post your timed queries in this forum.

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|07:12
|Please post your general queries on Python in this forum.

FOSSEE team coordinates the TBC project.

|-
|07:22
|Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India. For more details, visit this website.

|-
|07:33
|This is Priya from IIT Bombay signing off. Thanks for watching.

Python-3.4.3/C4/Testing-and-Debugging/English-timed - Revision history

PoojaMoolya: Created page with "{| border=1 |'''Time''' |'''Narration''' |- |00:01 |Welcome to the spoken tutorial on '''Testing and debugging.''' |- |00:06 |In this tutorial, you will, Understand what is..."