Difference between revisions of "Python-3.4.3/C2/Additional-features-of-IPython/English-timed"

From Script | Spoken-Tutorial
Jump to: navigation, search
(Created page with "{| border=1 | <center>'''Time'''</center> | <center>'''Narration'''</center> |- | 00:01 | Hello friends and welcome to the Spoken Tutorial on''' Additional Features of IPytho...")
 
Line 344: Line 344:
 
| '''percentage save filename'''
 
| '''percentage save filename'''
  
'''percentage save 2 hyphen 5 7 9 hyphen 11'''
+
'''percentage save 2 hyphen 5 7 9 10 and 11'''
  
 
|-
 
|-

Revision as of 06:14, 13 June 2019

Time
Narration
00:01 Hello friends and welcome to the Spoken Tutorial on Additional Features of IPython.
00:07 At the end of this tutorial, you will be able to, Retrieve your IPython history.
00:14 View a part of the history.
00:17 Save a part of a history to a file.
00:21 Run a script from within IPython.
00:25 To record this tutorial, I am using Ubuntu Linux 14.04 operating system
00:32 Python 3.4.3

IPython 5.1.0

00:38 To practice this tutorial, you should know how to

use Plots interactively and embellish a plot

00:48 If not, see the pre-requisite Python tutorials on this website.
00:54 Let us now open the Terminal by pressing Ctrl+Alt+T keys simultaneously.
01:01 Now, type ipython3 and press Enter.
01:07 Let us initialise the pylab package. Type percentage pylab and press Enter
01:14 To start plotting, type x is equal to linspace inside the brackets minus 2pi comma 2pi comma 100 and press Enter.
01:31 Next type plot inside the brackets x comma xsin(x) and press Enter
01:42 We got an error saying "xsin is not defined".

This is because xsin(x) is actually x multiplied by sin(x)

01:54 Here, multiplication sign is missing. So let us now type

plot inside the brackets x comma x multiplied by sin(x) and press Enter.

02:13 Next let us add title and the labels for both x and y axes.
02:19 Type xlabel inside the brackets inside inverted commas inside dollar sign x and press Enter.
02:31 ylabel inside the brackets inside inverted commas inside dollar sign f(x)
02:43 Title inside the brackets inside 'inverted commas inside dollar sign x and xsin(x)
02:57 We can now see the labelled plot.
03:01 The history of typed commands can be retrieved by the percentage history command.
03:07 Type percentage history and press Enter.
03:13 percentage history itself is a command and is displayed as the most recent command.
03:20 Whatever we executed in the terminal is stored as history.
03:25 If we want to see what was the fifth command, pass 5 as an argument to percentage history command.
03:33 Type percentage history space 5 and press Enter.

This displays the fifth command which we typed.

03:43 Now pause the video here, and try out the following exercise and resume the video.
03:49 Find out how to list the recent commands between 5 and 10.
03:55 Switch back to terminal.
03:58 Let us look at the solution.
04:00 Type clf() and Press Enter.

Type percentage history question mark

04:08 Read through the information of percentage history command.
04:13 We can see, percentage history hyphen n 4 hyphen 6 displays the commands from 4 to 6.
04:24 Here hyphen n is an optional argument which prints the line numbers.

Type q to quit the documentation

04:37 Now type percentage history space 5 hyphen 10 and press Enter.
04:46 To save the history, we use the percentage save command.
04:51 Before we do that, let us first look at the history and identify which lines of code we require.
04:58 Type percentage history and press Enter.
05:03 The second command is linspace.

But the third command is a command that gave us an error.

05:10 Hence we do not need it.
05:13 The commands from fourth to seventh are required.
05:16 So we need the second command and then the fourth to seventh commands for our program.
05:22 Let us save it in the present working directory. Hence the syntax will be

percentage save space plot underscore script.py space 2 space 4 hyphen 7 and press Enter

05:47 The first argument in percentage save command is the name of the file in which the commands are saved.
05:56 The second argument gives the numbers of the commands that are being saved separated by spaces.
06:04 Let us now open the file plot underscore script.py and see the contents.
06:13 Let us learn how to run the file as a python script.

We use the command percentage run to do this.

06:22 Type percentage run space hyphen i space plot underscore script.py and press Enter.
06:38

Here, hyphen i parameter runs the code written in a text editor.

The code is run within the current ipython session.

06:50 It uses the variables defined interactively in the ipython session.
06:56 The script runs but we do not see the plot.
07:01 This is because when we are running a script, we are not in the interactive mode.
07:07 To view the plot, type show() on your terminal and press Enter.
07:15 Pause the video here, and try out the following exercise and resume.
07:21 Use percentage history and percentage save to create a script that has the function show() in it.
07:30 Run the script to produce the plot and display the same.
07:35 Let us look at the solution.

We first look at the history using the percentage history hyphen n command.

07:44 Type percentage history space hyphen n and press Enter.
07:54 Let us clear the plot window

Type clf() and press Enter

08:01 Now let us save the script using the command percentage save
08:07 We need lines 2, then 4 to 7 and 16
08:20 Type percentage save space show underscore included.py space 2 space 4 hyphen 7 space 16 and press Enter
08:41 To run the script type

percentage run space hyphen i space show underscore included.py

And press Enter

08:57 We get the desired plot.
09:01 Go to the previous command.

'Modify it by removing ‘hyphen i’ in the command to, percentage run space show included.py and Press Enter


09:16 We see that it raises a NameError saying that the name linspace is not defined.

This happens because we did not run the script interactively.

09:30 This brings us to the end of this tutorial. In this tutorial,we have learnt to,

Retrieve the history using percentage history command.

09:41 View only a part of history by passing argument to percentage history command.
09:48 Save the required lines of code in required order using percentage save command.
09:55 Use 'percentage run space hyphen i' command to run a saved script.
10:04 Here are some self assessment questions
10:08 How do you save the command lines 2 3 4 5 7 9 10 and 11?
10:17 percentage save filename 2-5 7 9 hyphen 11
10:25 percentage save filename 2 hyphen 11
10:30 percentage save filename

percentage save 2 hyphen 5 7 9 10 and 11

10:40 Which is the command to run the script?

Percentage execute the script name

10:46 percentage run hyphen i script name

percentage run script name

10:53 percentage execute hyphen i script name
10:58 And the solutions are,

To save the commands 2 3 4 5 7 9 10 11, we issue the command percentage save filename 2 hyphen 5 space 7 space 9 hyphen 11

11:18 To run the script we use percentage run space hyphen i space scriptname
11:27 Please post your timed queries in this forum.
11:32 Please post your general queries on Python in this forum.
11:37 The FOSSEE team coordinates the TBC project.
11:41 Spoken Tutorial Project is funded by NMEICT, MHRD, Govt. of India.

For more details, visit this website.

11:52 This is Usha from IIT Bombay (or FOSSEE, if you wish) signing off.

Contributors and Content Editors

PoojaMoolya, Sandhya.np14