Difference between revisions of "Python-3.4.3/C2/Getting-started-with-IPython/English-timed"

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|  Let us now try a few more operations such as-  
 
|  Let us now try a few more operations such as-  
  
−
5 minus 3,  
+
'''5 minus 3''',  
  
−
7 multiplied by 4.  
+
'''7 multiplied by 4'''.  
  
 
|-  
 
|-  
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|  The '''interpreter '''prints the result as '''3'''.  
 
|  The '''interpreter '''prints the result as '''3'''.  
  
−
Notice that this time, the indication '''Out''' square brackets is not displayed.  
+
Notice that this time, the indication '''Out''' square brackets, is not displayed.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 04:21
 
| 04:21
−
| As with any programming language, '''asterix '''is used for '''multiplication operator'''.  
+
| As with any programming language, '''asterisk '''is used for multiplication operator.  
  
 
|-  
 
|-  
 
| 04:27
 
| 04:27
−
|  Observe the output on the '''console'''.  
+
|  Observe the '''output''' on the '''console'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
|  04:35
 
|  04:35
−
|  Suppose we want to use the '''function print'''.  
+
|  Suppose we want to use the '''function "print"'''.  
  
 
|-  
 
|-  
 
| 04:39
 
| 04:39
−
| For this we just type '''pri''' at the '''prompt''' and press the '''tab key'''.  
+
| For this, we just type '''pri''' at the '''prompt''' and press the '''tab key'''.  
  
 
|-  
 
|-  
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| Pause the video, solve the problem and resume the video.  
 
| Pause the video, solve the problem and resume the video.  
  
−
find out the '''commands''' starting with "'''ab'''".  
+
Find out the '''command'''s starting with "'''ab'''".  
 
|-  
 
|-  
 
| 05:31
 
| 05:31
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|-  
 
|-  
 
| 05:40
 
| 05:40
−
| '''a tab''' displays a list of all the '''commands''' starting with '''a'''.  
+
| '''a tab''' displays a list of all the '''command'''s starting with '''a'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 05:55
 
| 05:55
−
| To see the documentation of a '''function''', type the '''function '''name followed by a '''question mark'''.  
+
| To see the documentation of a '''function''', type the '''function '''name followed by a question mark.  
  
 
|-  
 
|-  
 
| 06:03
 
| 06:03
−
| The '''IPython interpreter '''will show the documentation for the '''function'''.  
+
| The '''IPython interpreter '''will show the '''documentation''' for the '''function'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
|  06:16
 
|  06:16
−
|  Let us see a few examples. On the '''console''', type '''a b s minus 19''' and then '''a b s 19'''.  
+
|  Let us see a few examples. On the '''console''', type: '''a b s minus 19''' and then '''a b s 19'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 06:42
 
| 06:42
−
| We get 10.5 as the result.  
+
| We get '''10.5''' as the result.  
  
 
|-  
 
|-  
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|  Switch to the '''console''' for the solution.  
 
|  Switch to the '''console''' for the solution.  
  
−
You can look up the documentation of the '''function round''' by typing '''round question mark'''.  
+
You can look up the documentation of the '''function round''' by typing '''round''' question mark.  
  
 
|-  
 
|-  
 
| 07:06
 
| 07:06
−
| It says here that the '''function round, rounds''' a number to a given '''precision'''.  
+
| It says here that the '''function 'round'''', rounds a number to a given precision.  
  
 
|-  
 
|-  
 
|  07:12
 
|  07:12
−
|  '''ndigits '''is the '''precision''' value for '''round function'''.  
+
|  '''ndigits '''is the precision value for '''round''' function.  
  
 
Notice, there are extra square brackets around '''ndigits'''.  
 
Notice, there are extra square brackets around '''ndigits'''.  
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|-  
 
|-  
 
| 07:27
 
| 07:27
−
| Optional parameters are shown in square brackets in '''Python''' documentation.  
+
| Optional '''parameter'''s are shown in square brackets in '''Python''' documentation.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 07:38
 
| 07:38
−
| Check the output of  
+
| Check the output of:
  
−
'''round 2.48,  round 2.48 comma 1,  round 2.484,  round 2.484 comma 2 '''  
+
'''round 2.48''',   
 +
'''round 2.48 comma 1''',   
 +
'''round 2.484''',   
 +
'''round 2.484 comma 2'''
  
 
|-  
 
|-  
 
|  07:52
 
|  07:52
−
|  We get '''round 2.48 is equal to 2.0'''  
+
|  We get '''round 2.48 is equal to 2.0''',
  
 
|-  
 
|-  
 
| 07:57
 
| 07:57
−
| '''round 2.48 comma 1 is 2.5'''  
+
| '''round 2.48 comma 1 is 2.5''',
  
 
|-  
 
|-  
 
| 08:02
 
| 08:02
−
| '''round 2.484 is 2.0'''  
+
| '''round 2.484 is 2.0''',
  
 
|-  
 
|-  
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|-  
 
|-  
 
|  08:13
 
|  08:13
−
|  Let us now see how to correct typing errors, which we could make while typing on the '''console'''.  
+
|  Let us now see how to correct typing errors which we could make while typing on the '''console'''.  
 
|-  
 
|-  
 
| 08:20
 
| 08:20
 
| Let us make a typing error deliberately.  
 
| Let us make a typing error deliberately.  
  
−
Type '''round open parenthesis 2.484''' and press '''Enter''', without closing the '''parenthesis'''.  
+
Type: '''round open parenthesis 2.484''' and press '''Enter''', without closing the parenthesis.  
  
 
|-  
 
|-  
 
| 08:32
 
| 08:32
−
|  We get a '''prompt '''with dots.  
+
|  We get a prompt with dots.  
  
−
This '''prompt '''is the '''continuation prompt '''of '''IPython'''.  
+
This prompt is the continuation prompt of '''IPython'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
|  08:44
 
|  08:44
−
|  Now complete the '''command''' with '''close parenthesis '''and press '''Enter'''.  
+
|  Now complete the '''command''' with close parenthesis and press '''Enter'''.  
  
−
We get the expected output, that is 2.  
+
We get the expected output, that is '''2'''.  
  
 
|-  
 
|-  
 
|  08:54
 
|  08:54
−
|  What if we type an incorrect '''command '''and end up with the '''continuation prompt'''?  
+
|  What if we type an incorrect '''command '''and end up with the continuation prompt?  
  
 
|-  
 
|-  
 
| 09:00
 
| 09:00
−
| In such case, we can press '''Ctrl+C''' keys, to interrupt the '''command''' and get back to the '''IPython prompt'''.  
+
| In such case, we can press '''Ctrl+C''' keys to interrupt the '''command''' and get back to the '''IPython prompt'''.  
  
 
|-  
 
|-  
 
| 09:09
 
| 09:09
−
| '''round''' takes only numbers as input. Type '''round(1a'''  
+
| '''round''' takes only numbers as input. Type: '''round(1a'''  
  
 
|-  
 
|-  
 
| 09:15
 
| 09:15
−
| Do not close the '''parenthesis''' and press''' Enter. '''  
+
| Do not close the parenthesis and press''' Enter. '''  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 09:34
 
| 09:34
−
| Type '''round 2.484,''' without closing the '''parenthesis''' and press '''Enter'''.  
+
| Type: '''round 2.484,''' without closing the parenthesis and press '''Enter'''.  
  
 
|-  
 
|-  
 
| 09:41
 
| 09:41
−
| Then cancel the '''command''' using '''Ctrl+C'''. Type the '''command round 2.484 comma 2 '''  
+
| Then cancel the '''command''' using '''Ctrl+C'''. Type the command '''round 2.484 comma 2 '''  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 10:04
 
| 10:04
−
| In this tutorial,we have learnt to, invoke the '''IPython interpreter '''by typing '''ipython''' in the '''terminal'''.
+
| In this tutorial, we have learnt to:
 +
invoke the '''IPython interpreter '''by typing '''ipython''' in the '''terminal''',
  
 
|-  
 
|-  
 
| 10:13
 
| 10:13
−
| Quit the '''IPython interpreter '''by using '''Ctrl+D'''.
+
| quit the '''IPython interpreter '''by using '''Ctrl+D''',
  
 
|-  
 
|-  
 
| 10:17
 
| 10:17
−
| Navigate the '''IPython session''' history by using the arrow keys.
+
| navigate the '''IPython session''' history by using the arrow keys,
  
 
|-  
 
|-  
 
| 10:23
 
| 10:23
−
| Use  '''tab-completion''' to work faster.
+
| Use  '''tab-completion''' to work faster,
  
 
|-  
 
|-  
 
| 10:27
 
| 10:27
−
| See the documentation of '''functions '''using '''question mark'''.
+
| see the documentation of '''functions '''using '''question mark''',
  
 
|-  
 
|-  
 
| 10:32
 
| 10:32
−
| Interrupt commands using '''Ctrl+C''' when we make an error.  
+
| interrupt commands using '''Ctrl+C''' when we make an error.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 10:41
 
| 10:41
−
|  '''IPython is a programming language similar to Python.'''True or False  
+
|  '''IPython is a programming language similar to Python.''' '''True''' or '''False'''
  
 
|-  
 
|-  
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| Which key combination quits '''IPython'''?  
 
| Which key combination quits '''IPython'''?  
  
−
'''Ctrl + C''' ,  '''Ctrl + D''' ,  '''Alt + C''' , '''Alt + D'''   
+
'''Ctrl + C'''
 +
 
 +
'''Ctrl + D'''
 +
 
 +
'''Alt + C'''
 +
 
 +
'''Alt + D'''   
  
 
|-  
 
|-  
 
| 10:55
 
| 10:55
−
|  Which character is used at the end of a '''command''', in '''IPython''' to display the documentation?  
+
|  Which character is used at the end of a '''command''' in '''IPython''' to display the documentation?  
  
−
'''under score ''' , '''question mark ''',  '''exclamation mark ''' ,  '''ampersand '''  
+
'''under score'''
 +
 +
'''question mark'''
 +
 
 +
'''exclamation mark'''
 +
 
 +
'''ampersand '''  
  
 
|-  
 
|-  
 
|  11:07
 
|  11:07
−
|  And the answers are- '''False. IPython''' is not a new programming language. It is just an enhanced interactive '''Python interpreter'''.  
+
|  And, the answers are- '''False. IPython''' is not a new programming language. It is just an enhanced interactive '''Python interpreter'''.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
|  11:28
 
|  11:28
−
|  This video summarises the Spoken Tutorial project.  
+
|  This video summarises the '''Spoken Tutorial''' project.  
  
 
If you do not have good bandwidth, you may download and watch it.  
 
If you do not have good bandwidth, you may download and watch it.  
Line 505: Line 521:
 
|-  
 
|-  
 
|  11:37
 
|  11:37
−
|  We conduct workshops. Give Certificates. Please contact us.  
+
|  We conduct workshops, give certificates. Please contact us.  
  
 
|-  
 
|-  
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|-  
 
|-  
 
| 11:48
 
| 11:48
−
| Explain your question briefly.  
+
| Explain your question briefly. Someone from the '''FOSSEE''' team will answer them.  
−
 
+
−
Someone from the '''FOSSEE''' team will answer them.  
+
  
 
Please visit this site.  
 
Please visit this site.  
Line 541: Line 555:
 
|-  
 
|-  
 
| 12:17
 
| 12:17
−
|  The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India  
+
|  The '''Spoken Tutorial''' project is funded by '''NMEICT, MHRD,''' Govt. of India.
  
 
|-  
 
|-  
 
|  12:23
 
|  12:23
−
|  This is Prabhu from IIT Bombay signing off. Thanks for watching  
+
|  This is Prabhu from '''IIT Bombay''', signing off. Thanks for watching.
  
 
|}
 
|}

Latest revision as of 16:46, 11 June 2019

Time
Narration
00:01 Hello friends. Welcome to the tutorial on Getting started with IPython.
00:07 At the end of this tutorial, you will be able to: invoke the IPython interpreter,
00:13 quit the IPython interpreter,
00:16 navigate the IPython session history,
00:20 use tab-completion within IPython,
00:23 look up documentation in IPython,
00:26 interrupt incomplete or incorrect commands.
00:30 To record this tutorial, I am using:

Ubuntu Linux 14.04 operating system,

00:37 Python 3.5.2,

IPython 5.1.0

00:44 What is IPython?

IPython is an enhanced interactive Python interpreter.

00:50 It provides features like tab-completion and easier access to help.
00:56 Let us first see how to start the IPython interpreter.
01:00 First open the terminal by pressing Ctrl+Alt+T keys simultaneously on the keyboard.
01:07 Type ipython3 at the prompt and press Enter.
01:13 If IPython is not installed, please refer to the Instruction sheet.
01:18 If IPython is installed, the IPython interpreter is loaded by running the ipython command in the terminal.
01:25 The versions of Python and IPython that are installed, are shown on the terminal.
01:32 Some additional helpful information is printed by IPython.
01:37 After this, we get a prompt with i n bracket 1:
01:42 Now, let us see how we can quit the IPython interpreter.

Press Ctrl+D keys.

01:48 A prompt will appear to confirm if we really want to exit.
01:53 Type y for yes and quit IPython.
01:57 Note that y is given in square brackets. So, it is default.
02:02 We could also press Enter and it will exit.
02:05 Else, type n for no if you don't want to quit IPython.
02:10 Let us type y.

We have quit IPython interpreter and are back at the terminal prompt.

02:16 Let us start it again.

Type ipython3 in the terminal and press Enter.

02:23 Now, let us learn how to use the interpreter.

Let us start with the simplest operation - addition.

02:30 Type: 1 plus 2 at the IPython prompt and press Enter.
02:36 We press Enter to execute the python command. Please do so, after typing every command.
02:43 IPython promptly displays the output as 3.
02:47 Notice that the output is shown with an Out square brackets 1 indication.
02:54 Let us now try a few more operations such as-

5 minus 3,

7 multiplied by 4.

03:03 Each time we press Enter and see the output on the IPython console window.
03:10 Let us see how we can navigate to previous commands in IPython.
03:15 For example, say, we want to execute print open parenthesis 1 plus 2 close parenthesis.
03:23 Instead of typing the whole command, we can recall the command 1 plus 2 we typed earlier.
03:30 Use the up arrow key to go back to the command 1 plus 2.
03:35 Now use the left-arrow key to navigate to the beginning of the line.
03:40 Type the word print, open parenthesis close parenthesis, on the keyboard.
03:49 We have changed the command to print (1 plus 2). Now press Enter.
03:53 The interpreter prints the result as 3.

Notice that this time, the indication Out square brackets, is not displayed.

04:03 Now let us execute print 10 multiplied by 2.

We use the up arrow key to navigate to the previous command print (1 plus 2).

04:14 Now replace 1 plus 2 with 10 multiplied by 2 and press Enter.
04:21 As with any programming language, asterisk is used for multiplication operator.
04:27 Observe the output on the console.
04:30 Now, let us see, what is tab-completion.

Let us consider an example.

04:35 Suppose we want to use the function "print".
04:39 For this, we just type pri at the prompt and press the tab key.
04:45 As you can see on the console that IPython has autocompleted the command pri to print.
04:52 This feature of IPython is called the tab-completion.
04:56 Let us see some more possibilities of tab completion.

Just type p and then press the tab.

05:05 In this case, we see that IPython does not complete the command.
05:09 This is because, there are more than one command beginning with p.
05:14 Therefore, it just lists out all the possible tab-completions of p.
05:20 Now let us try out an exercise.
05:23 Pause the video, solve the problem and resume the video.

Find out the commands starting with "ab".

05:31 List out the commands starting with "a".
05:35 ab autocompletes to a b s abs.
05:40 a tab displays a list of all the commands starting with a.
05:46 Now, let us see what the function abs is used for.
05:51 We will use the help feature of IPython to find out this.
05:55 To see the documentation of a function, type the function name followed by a question mark.
06:03 The IPython interpreter will show the documentation for the function.
06:08 From the displayed information, it says abs accepts a number as input and returns it's absolute value.
06:16 Let us see a few examples. On the console, type: a b s minus 19 and then a b s 19.
06:29 We get 19, as expected, in both the cases.
06:33 Now let us try it for decimal numbers.

Let us try a b s minus 10.5.

06:42 We get 10.5 as the result.
06:46 Pause the video here.

Try out the following exercise and resume the video.

06:52 Look-up the documentation of round and see how to use it.
06:57 Switch to the console for the solution.

You can look up the documentation of the function round by typing round question mark.

07:06 It says here that the function 'round', rounds a number to a given precision.
07:12 ndigits is the precision value for round function.

Notice, there are extra square brackets around ndigits.

07:21 This means that ndigits is optional and 0 is the default value.
07:27 Optional parameters are shown in square brackets in Python documentation.
07:33 Pause the video here.

Try out the following exercise and resume the video.

07:38 Check the output of:

round 2.48, round 2.48 comma 1, round 2.484, round 2.484 comma 2

07:52 We get round 2.48 is equal to 2.0,
07:57 round 2.48 comma 1 is 2.5,
08:02 round 2.484 is 2.0,
08:06 round 2.484 comma 2 is 2.48

which are what we expect.

08:13 Let us now see how to correct typing errors which we could make while typing on the console.
08:20 Let us make a typing error deliberately.

Type: round open parenthesis 2.484 and press Enter, without closing the parenthesis.

08:32 We get a prompt with dots.

This prompt is the continuation prompt of IPython.

08:40 It appears when the previous line is incomplete.
08:44 Now complete the command with close parenthesis and press Enter.

We get the expected output, that is 2.

08:54 What if we type an incorrect command and end up with the continuation prompt?
09:00 In such case, we can press Ctrl+C keys to interrupt the command and get back to the IPython prompt.
09:09 round takes only numbers as input. Type: round(1a
09:15 Do not close the parenthesis and press Enter.
09:19 We gave alpha-numeric value '1 a' as input.

Press Ctrl+C to interrupt the execution.

09:28 Pause the video here.

Try out the following exercise and resume the video.

09:34 Type: round 2.484, without closing the parenthesis and press Enter.
09:41 Then cancel the command using Ctrl+C. Type the command round 2.484 comma 2
09:51 The output on your console should look like this.
10:01 This brings us to the end of this tutorial.
10:04 In this tutorial, we have learnt to:

invoke the IPython interpreter by typing ipython in the terminal,

10:13 quit the IPython interpreter by using Ctrl+D,
10:17 navigate the IPython session history by using the arrow keys,
10:23 Use tab-completion to work faster,
10:27 see the documentation of functions using question mark,
10:32 interrupt commands using Ctrl+C when we make an error.
10:37 Here are some self assessment questions for you to solve.
10:41 IPython is a programming language similar to Python. True or False
10:46 Which key combination quits IPython?

Ctrl + C

Ctrl + D

Alt + C

Alt + D

10:55 Which character is used at the end of a command in IPython to display the documentation?

under score

question mark

exclamation mark

ampersand

11:07 And, the answers are- False. IPython is not a new programming language. It is just an enhanced interactive Python interpreter.
11:17 We use Ctrl + D to quit IPython interpreter.
11:21 We use question mark (?) at the end of the command to display its documentation.
11:28 This video summarises the Spoken Tutorial project.

If you do not have good bandwidth, you may download and watch it.

11:37 We conduct workshops, give certificates. Please contact us.
11:42 Do you have questions in THIS Spoken Tutorial?

Choose the minute and second where you have the question.

11:48 Explain your question briefly. Someone from the FOSSEE team will answer them.

Please visit this site.

11:56 Do you have any general / technical questions in Python?
11:59 Please visit the FOSSEE forum and post your question.
12:04 The FOSSEE team coordinates coding of several solved examples of popular books.
12:10 We give honorarium and certificates for those who do this.

For more details, please visit this site.

12:17 The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India.
12:23 This is Prabhu from IIT Bombay, signing off. Thanks for watching.

Contributors and Content Editors

PoojaMoolya, Sandhya.np14

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