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

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|-
 
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| 04:39
 
| 04:39
| 1. find out the commands starting with "ab"?
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| 1. Find out the commands starting with "ab"?
  
 
|-
 
|-
 
| 04:44
 
| 04:44
| 2. list out the commands starting with "a"?
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| 2. List out the commands starting with "a"?
  
 
|-
 
|-
 
| 04:54
 
| 04:54
|'' ab'' tab completes to''abs'' and ''a tab gives us a list of all the commands starting with a.
+
|'' ab'' tab completes to''abs'' and ''a'' tab gives us a list of all the commands starting with 'a'.
  
 
|-
 
|-
 
| 05:07
 
| 05:07
| Now, let's see what the functions abs is used for.
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| Now, let's see what the functions 'abs' is used for.
  
 
|-
 
|-
 
| 05:12
 
| 05:12
| We will use the help features of ipython to find out this.
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| We will use the '''help''' features of ipython to find out this.
  
 
|-
 
|-
 
|05:15
 
|05:15
| To see the documentation of a function, type the function name followed by a question mark and hit enter.
+
| To see the documentation of a function, type the function name followed by a question mark and hit '''Enter'''.
  
 
|-
 
|-
 
| 05:24
 
| 05:24
| Ipython interpreter will show the documentation for the function.
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| '''ipython interpreter''' will show the documentation for the function.
  
 
|-
 
|-
 
| 05:27
 
| 05:27
| Let us see the documentation of the function abs, type abs? and press enter
+
| Let us see the documentation of the function 'abs', type: "abs?" and press '''Enter'''.
  
 
|-
 
|-
 
| 05:38
 
| 05:38
| As the documentation says, ''abs'' accepts a number as an input and returns it's absolute value.
+
| As the documentation says, '''abs''' accepts a number as an input and returns it's '''absolute value'''.
  
 
|-
 
|-
 
| 05:46
 
| 05:46
|lets see few examples,
+
|Let's see few examples.
  
 
|-
 
|-
 
| 05:49
 
| 05:49
|Type ''abs(-19)'' and'' abs(19)'' on the interpreter.
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|Type: '''abs(-19)''' and''' abs(19)''' on the interpreter.
  
 
|-
 
|-
 
| 06:04
 
| 06:04
|We get ''19'', as expected, in both the cases.
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|We get ''19'' as expected, in both the cases.
  
 
|-
 
|-
 
| 06:08
 
| 06:08
| Now lets try it for decimal numbers; lets try'' abs(-10.5)'', we got ''10.5'' as the result.
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| Now let's try it for decimal numbers; let's try '''abs(-10.5)''', we got ''10.5'' as the result.
  
 
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|-
 
|-
 
| 06:31
 
| 06:31
|Look-up the documentation of ''round'' and see how to use it.
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|Look-up the documentation of '''round''' and see how to use it.
  
 
|-
 
|-
 
| 06:39
 
| 06:39
| And you can look up the documentation of the function round by typing round ''question mark'' in the ipython interpreter.
+
| And you can look up the documentation of the function '''round''' by typing '''round ''question mark'' ''' in the 'ipython interpreter'.
  
 
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| 07:03
 
| 07:03
|A function ''round'', rounds a number to a given precision.
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|A function '''round''', rounds a number to a given precision.
  
 
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|-
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|-
 
|-
 
| 07:16
 
| 07:16
| let us now try few more examples with the function round.
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| Let us now try few more examples with the function '''round'''.
  
 
|-
 
|-
 
| 07:21
 
| 07:21
| Check the output of ''round(2.48) round(2.48, 1) round(2.48, 2) round(2.484) round(2.484, 1) round(2.484, 2)''
+
| Check the output of '''round(2.48) round(2.48, 1) round(2.48, 2) round(2.484) round(2.484, 1) round(2.484, 2)'''.
  
 
|-
 
|-
 
| 07:43
 
| 07:43
| Now, we got'' 2.0, 2.5 and 2.48'', which are what we expect.
+
| Now, we got''' 2.0, 2.5''' and '''2.48''' which are what we expect.
  
 
|-
 
|-
 
| 07:54
 
| 07:54
| Let's now see how to correct typing errors, which we often make while typing at the terminal.
+
| Let's now see how to correct typing errors which we often make while typing at the terminal.
  
 
|-
 
|-
 
| 08:01
 
| 08:01
| As already shown, if we haven't hit the enter key already, we could navigate using the arrow keys and make deletions using delete or backspace key and correct the errors.
+
| As already shown, if we haven't hit the '''Enter''' key already, we could navigate using the arrow keys and make deletions using delete or backspace key and correct the errors.
  
 
|-
 
|-
 
| 08:12
 
| 08:12
|let us make a typing error deliberately, type round(2.484 and hit enter, without closing the parenthesis.
+
|Let us make a typing error deliberately, type: '''round(2.484''' and hit '''Enter''', without closing the parenthesis.
  
 
|-
 
|-
 
| 08:25
 
| 08:25
| We get a prompt with ''dots'' .  
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| We get a prompt with '''dots''' .  
  
 
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| 08:32
 
| 08:32
| It appears when, the previous line is incomplete.
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| It appears when the previous line is incomplete.
  
 
|-
 
|-
 
| 08:36
 
| 08:36
| now complete the command of the same examples with close parenthesis and press enter.  
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| Now complete the '''command''' of the same example with close parenthesis and press '''Enter'''.  
  
 
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| 08:51
 
| 08:51
| In other instances, if we commit a typing error with a longer and more complex expression and end up with the continuation prompt, we can type Ctrl-C to interrupt the command and get back to the  ipython input prompt.
+
| In other instances, if we commit a typing error with a longer and more complex expression and end up with the continuation prompt, we can type '''Ctrl-C''' to interrupt the command and get back to the  ipython input prompt.
  
 
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| 09:22
 
| 09:22
| 1.type round(2.484, and press enter. and then cancel the command using ''Ctrl-C''.
+
| 1. Type '''round(2.484,''' and press '''Enter''' and then cancel the command using '''Ctrl-C'''.
  
 
|-
 
|-
 
| 09:45
 
| 09:45
| 2. type the command, round(2.484, 2)
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| 2. Type the command- '''round(2.484, 2)'''
  
 
|-
 
|-
 
| 10:09
 
| 10:09
| Now, let us revise quickly what we learn't today. In this tutorial,we learn't to,
+
| Now, let us revise quickly what we learn't today. In this tutorial, we learn't to:
  
 
|-
 
|-
 
| 10:15
 
| 10:15
| 1. Invoke the ipython interpreter by typing ipython.
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| 1. Invoke the 'ipython interpreter' by typing 'ipython'.
  
 
|-
 
|-
 
| 10:20
 
| 10:20
| 2. To quit the ipython  interpreter by using ctrl-d.
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| 2. To quit the 'ipython  interpreter' by using '''Ctrl-d'''.
  
 
|-
 
|-
 
| 10:22
 
| 10:22
| 3. To navigate in the history of  ipython  by using the arrow keys.
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| 3. To navigate in the '''history''' of  ipython  by using the arrow keys.
  
 
|-
 
|-
 
| 10:28
 
| 10:28
| 4. What is tab-completion  
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| 4. What is '''tab-completion'''.
  
 
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|-
 
| 10:34
 
| 10:34
| 6.  To Interrupt using ctrl-c when we make an error.
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| 6.  To Interrupt using '''Ctrl-c''' when we make an error.
  
 
|-
 
|-
 
| 10:39
 
| 10:39
| Here are some self assessment questions for you to solve
+
| Here are some self assessment questions for you to solve-
  
 
|-
 
|-
 
| 10:44
 
| 10:44
|  '''ipython is a programming language similar to Python.
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|  '''ipython''' is a programming language similar to Python.
  
 
|-
 
|-
 
| 10:50
 
| 10:50
|''' True or False''
+
|''' True or False'''?
  
 
|-
 
|-
 
| 10:53  
 
| 10:53  
| Second one. Which key combination quits ipython ? '' Ctrl + C Ctrl + D Alt + C Alt + D''
+
| Second one. Which key combination quits ipython ? '' Ctrl + C Ctrl + D Alt + C Alt + D''.
  
 
|-
 
|-
 
| 11:03
 
| 11:03
| And The last one. Which character is used at the end of a command, in Ipython to display the documentation. under score'' (_) ''question mark'' (?)'' exclamation mark'' (!)'' ampersand ''(&)''
+
| And The last one. Which character is used at the end of a command, in Ipython to display the documentation. under score'' (_), ''question mark'' (?)'', exclamation mark'' (!)'', ampersand ''(&)''.
  
 
|-
 
|-
 
| 11:16
 
| 11:16
| And the answers are,
+
| And the answers are-
  
 
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|-
 
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| 11:23
 
| 11:23
| Second one is We use ''Ctrl D'' to quit Ipython interpreter.
+
| Second one is We use ''Ctrl D'' to quit 'ipython interpreter'.
  
 
|-
 
|-
 
| 11:27
 
| 11:27
| The final one is We use ? at the end of the function name to display its documentation.
+
| The final one is- We use '?' at the end of the function name to display its documentation.
  
 
|-
 
|-
 
| 11:36
 
| 11:36
| So we hope you have enjoyed this tutorial and found it useful.  
+
| So, we hope you have enjoyed this tutorial and found it useful.  
  
 
|-
 
|-

Revision as of 23:16, 22 September 2015

Time Narration
00:00 Hello friends and welcome to the tutorial on Getting started with ipython.
00:07 At the end of this tutorial, you will be able to:
  1. invoke the ipython interpreter .
  2. quit the ipython interpreter.
  3. navigate the ipython session history.
  4. use tab-completion for writing ipython functions.
  5. look-up documentation of functions.
  6. interrupt incomplete or incorrect commands.
00:27 iPython is an enhanced Python interpreter that provides features like tab-completion, easier access to help and many other functionalities.
00:37 Let us first see how to start the ipython interpreter.
00:41 First, open the terminal. Type: "ipython" in the terminal and hit Enter.
00:51 After getting some information about the version of Python installed and some help commands, we get a prompt with In[1]:.
00:59 But, if you get an error saying 'ipython is not installed' then refer to the tutorial on how to install the packages.
01:09 Now, let's see how we can quit the 'ipython interpreter'. Press Ctrl, D.
01:17 A prompt will appear to confirm whether you really want to exit; type 'y' to say 'yes' and quit 'ipython' and 'n' to say 'no' if you don't want to quit the ipython.
01:28 Press 'y'.
01:32 Now, since we have quit the interpreter, let us start it again by typing "ipython".
01:42 And now let's see, how to use the interpreter.
01:46 Start with the simplest thing, addition.
01:48 type: 1+2at the prompt.
01:55 iPython promptly gives back the output as 3.
01:59 Notice that the output is displayed with an Out[1] indication.
02:05 Now, let us try few more operations such as- 5 minus 3, 7 minus 4, 6 into 5.
02:23 Now, let's see how the ipython remembers the history of commands.
02:29 For example,print 1+2.
02:33 Instead of typing the whole thing, use the up-arrow key to go back to the command 1+2 which we did before. Now use the left-arrow key to navigate to the beginning of the line and type the word "print" and press space.
02:55 We have changed the line to print 1+2, now press Enter.
03:02 The interpreter prints the result as 3.
03:06 Please note that the indication Out square brackets is not shown here.
03:11 Now, let us do print 10 into 2.
03:16 We use the up-arrow key to navigate to the previous command 1+2.
03:22 Now, change 1 plus 2 to 10 into 2 and press Enter.
03:34 Till now, we saw how to invoke the 'ipython interpreter', quit the ipython and navigate through previous commands in ipython.
03:42 Now, let's see, what is tab-completion?.
03:47 Let's take an example. Suppose, we want to use the function round.
03:52 For this, we just type ro at the prompt and press the tab key.
04:00 As you can see on the terminal, IPython completes the command ro into round. This feature of ipython is called the tab-completion.
04:08 Let's see some more possibilities of tab completion just type r and then press the tab.
04:19 As you can see that IPython does not complete the command. This is because, there are many possibilities of r therefore it just lists out all the possible completions of 'r'.
04:31 Now, let's try out an exercise.
04:33 Pause the video, solve the problem and resume the video.
04:39 1. Find out the commands starting with "ab"?
04:44 2. List out the commands starting with "a"?
04:54 ab tab completes toabs and a tab gives us a list of all the commands starting with 'a'.
05:07 Now, let's see what the functions 'abs' is used for.
05:12 We will use the help features of ipython to find out this.
05:15 To see the documentation of a function, type the function name followed by a question mark and hit Enter.
05:24 ipython interpreter will show the documentation for the function.
05:27 Let us see the documentation of the function 'abs', type: "abs?" and press Enter.
05:38 As the documentation says, abs accepts a number as an input and returns it's absolute value.
05:46 Let's see few examples.
05:49 Type: abs(-19) and abs(19) on the interpreter.
06:04 We get 19 as expected, in both the cases.
06:08 Now let's try it for decimal numbers; let's try abs(-10.5), we got 10.5 as the result.
06:24 Pause the video here, try out the following exercise and resume the video.
06:31 Look-up the documentation of round and see how to use it.
06:39 And you can look up the documentation of the function round by typing round question mark in the 'ipython interpreter'.
06:47 If you notice, there are extra square brackets around ndigits.
06:53 This means that ndigits is optional and 0 is the default value.
06:58 Optional parameters are shown in square brackets in Python documentation.
07:03 A function round, rounds a number to a given precision.
07:09 Pause the video here, try out the following exercise and resume the video.
07:16 Let us now try few more examples with the function round.
07:21 Check the output of round(2.48) round(2.48, 1) round(2.48, 2) round(2.484) round(2.484, 1) round(2.484, 2).
07:43 Now, we got 2.0, 2.5 and 2.48 which are what we expect.
07:54 Let's now see how to correct typing errors which we often make while typing at the terminal.
08:01 As already shown, if we haven't hit the Enter key already, we could navigate using the arrow keys and make deletions using delete or backspace key and correct the errors.
08:12 Let us make a typing error deliberately, type: round(2.484 and hit Enter, without closing the parenthesis.
08:25 We get a prompt with dots .
08:28 This prompt is the continuation prompt of ipython.
08:32 It appears when the previous line is incomplete.
08:36 Now complete the command of the same example with close parenthesis and press Enter.
08:49 We got the expected output that is 2.0
08:51 In other instances, if we commit a typing error with a longer and more complex expression and end up with the continuation prompt, we can type Ctrl-C to interrupt the command and get back to the ipython input prompt.
09:15 Pause the video here, try out the following exercise and resume the video.
09:22 1. Type round(2.484, and press Enter and then cancel the command using Ctrl-C.
09:45 2. Type the command- round(2.484, 2)
10:09 Now, let us revise quickly what we learn't today. In this tutorial, we learn't to:
10:15 1. Invoke the 'ipython interpreter' by typing 'ipython'.
10:20 2. To quit the 'ipython interpreter' by using Ctrl-d.
10:22 3. To navigate in the history of ipython by using the arrow keys.
10:28 4. What is tab-completion.
10:30 5. To see the documentation of functions using question mark.
10:34 6. To Interrupt using Ctrl-c when we make an error.
10:39 Here are some self assessment questions for you to solve-
10:44 ipython is a programming language similar to Python.
10:50 True or False?
10:53 Second one. Which key combination quits ipython ? Ctrl + C Ctrl + D Alt + C Alt + D.
11:03 And The last one. Which character is used at the end of a command, in Ipython to display the documentation. under score (_), question mark (?), exclamation mark (!), ampersand (&).
11:16 And the answers are-
11:18 Ipython is not a programming language, it is just an interpreter.
11:23 Second one is We use Ctrl D to quit 'ipython interpreter'.
11:27 The final one is- We use '?' at the end of the function name to display its documentation.
11:36 So, we hope you have enjoyed this tutorial and found it useful.
11:39 Thank you!

Contributors and Content Editors

Devraj, Gaurav, Minal, PoojaMoolya, Sandhya.np14, Sneha