Krupali: Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello friends and welcome to the tutorial on "Additional Features of IPython". |- | 0:06 | At the end of this tutorial, you will be ab…'

2013-10-30T04:59:03Z

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{| border=1
!Timing
!Narration
|-
| 0:00
| Hello friends and welcome to the tutorial on "Additional Features of IPython".

|-
| 0:06
| At the end of this tutorial, you will be able to,

# Retrieve your ipython history.
# View a part of the history.
# Save a part of your history to a file.
# Run a script from within ipython.

|-
| 0:19
| Before beginning this tutorial,we would suggest you to complete the tutorial on "Embellishing a plot".

|-
|0:24
|Let us start ipython with pylab loaded, by typing ipython hyphen pylab on the terminal.

|-
| 0:33
| We shall first make a plot and then view the history and save it, for that we can type x = linspace within brackets minus 2 into pi comma 2 into pi comma 100

plot within bracket x comma xsinx cosx and hit enter

|-
|1:00
| We got an error saying "xsinx is not defined".

|-
|1:04
|This is because xsin(x) is actually x star sin(x), for that we have type in the terminal
plot within bracket x comma x star sin(x)

plot x, sin(x)
xlabel within bracket in double quotes x
ylabel within bracket in double quotes dollar sign f(x) dollar sign
title within bracket in double quotes x and xsin(x)
title within bracket in double quotes dollar sign x and xsin(x) dollar sign

|-
| 2:15
| We now have the plot.

|-
|2:18
|Let us look at the commands that we have typed in.

|-
|2:21
| The history can be retrieved by using =modulo hist= command.

|-
|2:28
| Type modulo that is percentage sign hist in your terminal and hit enter

|-
| 2:37
| As you can see, it displays a list of recent commands that we typed.

|-
|2:41
| Every command has a number in front, to specify in which order and when it was typed.

|-
|2:48
|Please note that there is a percentage sign before the hist command.

|-
|2:52
| This implies that percentage hist is a command that is specific to IPython only and not to any other version of python.

|-
|3:00
| These other type of commands are called as magic commands.

|-
|3:04
|Also note that, the =%hist= itself is a command and is displayed as the most recent command.

|-
|3:15
| We should note that anything we type in is stored as history, irrespective of whether it is command or an error or IPython magic command.

|-
| 3:27
| If we want only the recent 5 commands to be displayed, we pass the number as an argument to =percentage hist= command.

|-
|3:35
| Hence percentage hist 5 displays the recent 5 commands, inclusive of the =percentage hist= command.

|-
|3:46
|The default number is 40.

|-
|3:48
|So to try this we can type in the terminal percentage hist space 5 and hit enter.

|-
| 3:58
| Pause the video here, try out the following exercise and resume the video.

|-
|4:02
|Read through the documentation of %hist and find out how to list all the commands between 5 and 10.

|-
| 4:11
| As we can see from =percentage hist= documentation,percentage hist 5 10 displays the commands from 5 to 10

|-
|4:22
|Now that we have the history, we will try it on the command prompt so type percentage hist 5 space 10 and hit enter.

|-
|4:35
| we would like to save the required line of code from history.

|-
|4:39
| This is possible by using the =percentage save= command.

|-
|4:47
| Before we do that, let us first look at history and identify what lines of code we require. So type percentage hist and hit enter.

|-
| 4:58
| The first command is linspace.

|-
| 5:00
| But second command is a command that gave us an error.

|-
|5:06
| Hence we do not need second command.

|-
|5:09
| The commands from third to sixth are required.

|-
|5:12
|The seventh command although is correct, we do not need it since we are setting the title correctly in the eighth command.

|-
| 5:20
| So we need first third to sixth and the eighth command for our program.

|-
|5:26
| Hence you can type in the syntax of percentage save slash home slash fossee slash plot underscore script dot py space 1 space 3 hyphen 6 space 8

|-
| 5:46
| The command saves the first line of code and then third to sixth followed by the eighth lines of code into the specified file.

|-
|5:55
|The first argument to percentage save is the path of file to save the commands and the arguments there after are the commands to be saved in the given order.

|-
| 6:08
| Pause the video here, try out the following exercise and resume the video.

|-
|6:11
|Change the label on y-axis to "y" and save the lines of code accordingly.

|-
| 6:17
| we use the command =ylabel= on interpreter

|-
|6:21
|ylabel within brackets in double quotes y and hit enter

|-
| 6:29
| and then you can do percentage save command

|-
|6:36
| That is you can type percentage save slash home slash fossee slash example underscore plot dot py space 1 space 3 hyphen 6 space 10

|-
|6:51
| Now that we have the required lines of code in a file, let us learn how to run the file as a python script.

|-
|6:58
|We use the IPython magic command =percentage run= to do this.

|-
|7:03
|Type percentage run space hyphen i space slash home slash fossee slash plot underscore script dot py

|-
|7:18
| The script runs but we do not see the plot. This happens because when we are running a script, we are not in the interactive mode anymore.

|-
|7:27
|Hence to view the plot type show then brackets on your terminal

|-
| 7:38
| So now Pause the video here, try out the following exercise and resume the video.

|-
|7:41
|Use percentage hist and percentage save and create a script that has the function show() in it.

|-
|7:49
| Run the script to produce the plot and display the name.

|-
|7:56
|So you can type percentage hist space 20 on the terminal

|-
|8:06
|We first look at the history using this command only,

|-
| 8:09
| Then save the script using the command percentage save space slash home slash fossee slash show underscore included dot py space 1 space 3 hyphen 6 space 8 , 14 and 17

|-
|8:37
| then on the next line you can type
percentage run hyphen i slash home slash fossee slash show underscore included dot py, then type show function to get the plot.

|-
| 9:03
| We get the desired plot now.

|-
|9:07
|The reason for including a hyphen i after run is to tell the interpreter that if any name is not found in script, search for it in the interpreter.

|-
|9:17
|Hence all these sin, plot, pi and show which are not available in script, are taken from the interpreter and used to run the script.

|-
| 9:32
| Pause the video here, try out the following exercise and resume the video.

|-
|9:36
|Run the script without using the hyphen i option.

|-
|9:42
|Do you find any difference?

|-
|9:47
|So you can type percentage run slash home slash fossee slash included hypen included dot py

|-
| 10:04
| We see that it raises Name Error saying that the name linspace is not found.

|-
|10:12
| This brings us to the end of this tutorial.

|-
|10:14
|In this tutorial,we have learnt to, Retrieve the history using =percentage hist= command.

|-
|10:21
|then View only a part of history by passing an argument to 'percentage hist' command.

|-
|10:25
|then Save the required lines of code in required order using 'percentage save' command.

|-
|10:30
|then Use 'percentage run hyphen i' command to run the saved script.

|-
| 10;39
| Here are some self assessment questions for you to solve

|-
|10:43
|5. How do you retrieve the recent 5 commands

|-
|10:46
| And there are four options percentage hist,percentage hist minus 5,percentage hist 5,percentage hist 5 to 10
|-
|10:57
|How do you save the lines 2 3 4 5 7 9 10 11 and the options are percentage save filepath 2 hyphen 5 7 9 hyphen 11,percentage save filepath 2 hyphen 11,percentage save filepath percentage save 2 hyphen 5 7 9 10 11

|-
|11:24
|And the final question is What will the command percentage hist 5 10 display.

|-
|11:30
| The recently typed commands from 5 to 10 inclusive of the history command

|-
|11:34
|The recently typed commands from 5 to 10 excluding the history command

|-
| 11:38
| So now the answers,

|-
|11:41
| In order to retrieve the recently typed 5 commands,we say percentage hist 5 for the first question.

|-
|11:49
|So second question answer is percentage save file path 2 hyphen 5 space 7 space 9 hyphen 11 is the correct option to the specified lines of codes.

|-
|12:02
| Then third answer is percentage hist 5 space 10 will display the recently typed commands from 5 to 10 inclusive of the history command.

|-
| 12:14
| This brings us to the end of this tutorial

|-
| 12:17
|So we Hope you have enjoyed and found it useful.Thank you.

Python/C2/Additional-features-of-IPython/Gujarati - Revision history

Krupali: Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello friends and welcome to the tutorial on "Additional Features of IPython". |- | 0:06 | At the end of this tutorial, you will be ab…'