Difference between revisions of "Python/C2/Getting-started-with-ipython/English-timed"
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| − | + | |'''Narration''' | |
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| + | | 00:00 | ||
| Hello Friends and Welcome to the tutorial on "getting started with ipython". | | Hello Friends and Welcome to the tutorial on "getting started with ipython". | ||
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| − | | | + | | 00:07 |
| At the end of this tutorial, you will be able to, | | At the end of this tutorial, you will be able to, | ||
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# look-up documentation of functions. | # look-up documentation of functions. | ||
# interrupt incomplete or incorrect commands. | # interrupt incomplete or incorrect commands. | ||
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| − | | | + | | 00:27 |
| IPython is an enhanced Python interpreter that provides features like tab-completion, easier access to help and many other functionalities. | | IPython is an enhanced Python interpreter that provides features like tab-completion, easier access to help and many other functionalities. | ||
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| − | | | + | | 00:37 |
|Let us first see how to start the ipython interpreter. | |Let us first see how to start the ipython interpreter. | ||
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| − | | | + | | 00:41 |
| First open the terminal, type ipython in the terminal and hit enter. | | First open the terminal, type ipython in the terminal and hit enter. | ||
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| − | | | + | | 00:51 |
| After getting some information about the version of Python installed and some help commands, we get a prompt with In[1]:. | | After getting some information about the version of Python installed and some help commands, we get a prompt with In[1]:. | ||
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| − | | | + | | 00:59 |
|But, if you get an error saying 'ipython is not installed' then refer to the tutorial on how to install the packages. | |But, if you get an error saying 'ipython is not installed' then refer to the tutorial on how to install the packages. | ||
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| − | | | + | | 01:09 |
| Now, lets see how we can quit the ipython interpreter, press Ctrl-D. | | Now, lets see how we can quit the ipython interpreter, press Ctrl-D. | ||
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| − | | | + | | 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. | | 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. | ||
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| − | | | + | | 01:28 |
| Press y. | | Press y. | ||
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| − | | | + | | 01:32 |
| Now since we have quit the interpretor, let us start it again by typing ipython | | Now since we have quit the interpretor, let us start it again by typing ipython | ||
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| − | | | + | | 01:42 |
| And now let's see, how to use the interpreter. | | And now let's see, how to use the interpreter. | ||
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| − | | | + | | 01:46 |
|Start with the simplest thing, addition. | |Start with the simplest thing, addition. | ||
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| − | | | + | | 01:48 |
|type ''1+2 ''at the prompt. | |type ''1+2 ''at the prompt. | ||
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| − | | | + | | 01:55 |
|IPython promptly gives back the output as ''3''. | |IPython promptly gives back the output as ''3''. | ||
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| − | | | + | | 01:59 |
|Notice that the output is displayed with an Out[1] indication. | |Notice that the output is displayed with an Out[1] indication. | ||
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| − | | | + | | 02:05 |
| Now, Let us now try few more operations such as, ''5 minus 3, 7 minus 4, 6 into 5''. | | Now, Let us now try few more operations such as, ''5 minus 3, 7 minus 4, 6 into 5''. | ||
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| − | | | + | | 02:23 |
| Now let's see how the ipython remembers the history of commands. | | Now let's see how the ipython remembers the history of commands. | ||
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| − | | | + | | 02:29 |
|For example ,''print 1+2''. | |For example ,''print 1+2''. | ||
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| − | | | + | | 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. | |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. | ||
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| We have changed the line to print 1+2, now press enter. | | We have changed the line to print 1+2, now press enter. | ||
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| − | | | + | | 03:02 |
|The interpreter prints the result as ''3''. | |The interpreter prints the result as ''3''. | ||
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| − | | | + | | 03:06 |
| Please note that the indication Out square brackets is not shown here. | | Please note that the indication Out square brackets is not shown here. | ||
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| − | | | + | | 03:11 |
| Now let us do print'' 10 into 2''. | | Now let us do print'' 10 into 2''. | ||
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| − | | | + | | 03:16 |
|We use the up arrow key to navigate to the previous command'' 1+2''. | |We use the up arrow key to navigate to the previous command'' 1+2''. | ||
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| − | | | + | |03:22 |
| Now change ''1 plus 2 to 10 into 2'' and press enter. | | Now change ''1 plus 2 to 10 into 2'' and press enter. | ||
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| − | | | + | | 03:34 |
| Till now, we saw how to invoke the ipython interpreter,quit the ipython and navigate through previous commands in ipython. | | Till now, we saw how to invoke the ipython interpreter,quit the ipython and navigate through previous commands in ipython. | ||
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| − | | | + | | 03:42 |
|Now, let's see, what is tab-completion?. | |Now, let's see, what is tab-completion?. | ||
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| − | | | + | | 03:47 |
|let's take an example, suppose we want to use the function round. | |let's take an example, suppose we want to use the function round. | ||
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| − | | | + | |03:52 |
| For this we just type ''ro'' at the prompt and press the tab key. | | For this we just type ''ro'' at the prompt and press the tab key. | ||
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| − | | | + | | 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. | | As you can see on the terminal, IPython completes the command ''ro'' into round, This feature of ipython is called the tab-completion. | ||
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| − | | | + | | 04:08 |
| Let's see some more possibilities of tab completion just type'' r'' and then press the'' tab''. | | Let's see some more possibilities of tab completion just type'' r'' and then press the'' tab''. | ||
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| − | | | + | | 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. | | 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. | ||
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| − | | | + | | 04:31 |
| Now let's try out an exercise. | | Now let's try out an exercise. | ||
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| − | | | + | | 04:33 |
| Pause the video,solve the problem and resume the video. | | Pause the video,solve the problem and resume the video. | ||
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| − | | | + | | 04:39 |
| 1. find out the commands starting with "ab"? | | 1. find out the commands starting with "ab"? | ||
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| − | | | + | | 04:44 |
| 2. list out the commands starting with "a"? | | 2. list out the commands starting with "a"? | ||
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| − | | | + | | 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. | ||
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| − | | | + | | 05:07 |
| Now, let's see what the functions abs is used for. | | Now, let's see what the functions abs is used for. | ||
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| − | | | + | | 05:12 |
| We will use the help features of ipython to find out this. | | We will use the help features of ipython to find out this. | ||
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| − | | | + | |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. | ||
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| − | | | + | | 05:24 |
| Ipython interpreter will show the documentation for the function. | | Ipython interpreter will show the documentation for the function. | ||
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| − | | | + | | 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 | ||
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| − | | | + | | 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. | ||
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| − | | | + | | 05:46 |
|lets see few examples, | |lets see few examples, | ||
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|Type ''abs(-19)'' and'' abs(19)'' on the interpreter. | |Type ''abs(-19)'' and'' abs(19)'' on the interpreter. | ||
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|We get ''19'', as expected, in both the cases. | |We get ''19'', as expected, in both the cases. | ||
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| − | | | + | | 06:08 |
| Now lets try it for decimal numbers; lets try'' abs(-10.5)'', we got ''10.5'' as the result. | | Now lets try it for decimal numbers; lets try'' abs(-10.5)'', we got ''10.5'' as the result. | ||
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| − | | | + | | 06:24 |
| Pause the video here, try out the following exercise and resume the video. | | Pause the video here, try out the following exercise and resume the video. | ||
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| − | | | + | | 06:31 |
|Look-up the documentation of ''round'' and see how to use it. | |Look-up the documentation of ''round'' and see how to use it. | ||
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| − | | | + | | 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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| − | | | + | | 06:47 |
| If you notice, there are extra square brackets around ''ndigits''. | | If you notice, there are extra square brackets around ''ndigits''. | ||
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| − | | | + | | 06:53 |
| This means that ''ndigits'' is optional and 0 is the default value. | | This means that ''ndigits'' is optional and 0 is the default value. | ||
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| − | | | + | | 06:58 |
| Optional parameters are shown in square brackets in Python documentation. | | Optional parameters are shown in square brackets in Python documentation. | ||
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| − | | | + | | 07:03 |
|A function ''round'', rounds a number to a given precision. | |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. | | Pause the video here, try out the following exercise and resume the video. | ||
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| − | | | + | | 07:16 |
| let us now try few more examples with the function round. | | let us now try few more examples with the function round. | ||
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| − | | | + | | 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)'' | ||
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| − | | | + | | 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. | ||
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| − | | | + | | 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. | ||
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|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. | ||
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| − | | | + | | 08:25 |
| We get a prompt with ''dots'' . | | We get a prompt with ''dots'' . | ||
|- | |- | ||
| − | | | + | | 08:28 |
|This prompt is the continuation prompt of ''ipython''. | |This prompt is the continuation prompt of ''ipython''. | ||
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| − | | | + | | 08:32 |
| It appears when, the previous line is incomplete. | | It appears when, the previous line is incomplete. | ||
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| − | | | + | | 08:36 |
| now complete the command of the same examples with close parenthesis and press enter. | | now complete the command of the same examples with close parenthesis and press enter. | ||
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| − | | | + | |08:49 |
|We got the expected output that is ''2.0'' | |We got the expected output that is ''2.0'' | ||
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| − | | | + | | 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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| − | | | + | | 09:15 |
| Pause the video here, try out the following exercise and resume the video. | | Pause the video here, try out the following exercise and resume the video. | ||
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| − | | | + | | 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''. | ||
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| − | | | + | | 09:45 |
| 2. type the command, round(2.484, 2) | | 2. type the command, round(2.484, 2) | ||
Revision as of 12:01, 10 July 2014
| 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,
|
| 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, lets 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 interpretor, 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+2 at 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 now 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+2which 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 | lets 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 lets try it for decimal numbers; lets 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 examples 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! |
