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

containing title, name of the production team along with the logo of MHRD

Objectives

1. Retrieve your IPython history.
2. View a part of the history.
3. Save a part of a history to a file.
4. Run a script from within IPython.

System Specifications

• Ubuntu Linux 14.04 operating system
• Python 3.4.3
• IPython 5.1.0

Pre-requisites

• use Plots interactively
• and embellish a plot

If not, see the pre-requisite Python tutorials on this website.

ipython3

Now, type ipython3 and press Enter.

%pylab and press Enter.

Type percentage pylab and press Enter

x = linspace(-2*pi, 2*pi, 100)

press Enter

plot(x, xsin(x))

press Enter

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

plot(x, x*sin(x))

Press Enter

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

Type

xlabel("$x$")

ylabel("$f(x)$")

title("$x and xsin(x)$")

Type

xlabel inside the brackets inside inverted commas inside dollar sign x press Enter.

ylabel inside the brackets inside inverted commas inside dollar sign f(x)

Title inside the brackets inside 'inverted commas inside dollar sign x and xsin(x)

We can now see the labelled plot.

Type %history and press Enter

Type percentage history and press Enter.

Whatever we executed in the terminal is stored as history.

Type %history 5 and press Enter

Type percentage history space 5 and press Enter.

This displays the fifth command which we typed.

Assignment 1

Find out how to list the recent commands between 5 and 10.

In examples of history doc, highlight

Example >> %history -n 4-6

Now quit history doc and type

%history 5-10 and press Enter

Type clf()

Type percentage history question mark

Read through the information of percentage history command.

We can see, percentage history hypen n 4 hypen 6 displays the commands from 4 to 6.

Here hypen n is an optional argument which prints line numbers.

Type q to quit the documentation

Now type percentage history space 5 hypen 10 and press Enter.

Type %history and press Enter

Type percentage history and press Enter.

Highlight the commands on the terminal.

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

Hence we do not need it.

The commands from fourth to seventh are required.

Type

%save plot_script.py 2 4-7

and press Enter

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 hypen 7. press Enter

Highlight the typed command on the terminal.

The second argument gives the numbers of the commands that are being saved separated by spaces.

Goto file plot_script.py. open and show it

Type

%run -i plot_script.py

and press Enter

We use the command percentage run to do this.

Type percentage run space hypen i space plot underscore script.py and press Enter.

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

The code is run within the current ipython session.

It uses the variables defined interactively in the ipython session.

Type

show()

and press Enter

This is because when we are running a script, we are not in the interactive mode.

To view the plot, type show() on your terminal. Press Enter.

Assignment 2

Use percentage history and percentage save to create a script that has the function show() in it.

Run the script to produce the plot and display the same.

%history -n

press Enter

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

Type percentage history space hypen n and press Enter.

Type clf()

press Enter

Type clf() and press Enter

Type

%save show_included.py 1 3-7 12 15

Press Enter

We need lines 2, 4 to 7 and 16

Type

percentage save space show underscore included.py space 2 space 4 hypen 7 space 16 and press Enter

Type

%run -i show_included.py

Press Enter

percentage run space hypen i space show underscore included.py

Then press Enter

Go to the previous command. Modify it by removing ‘-i’ in the command to, %run show_included.py

and Press Enter

Modify it by removing ‘hypen i’ in the command to,

percentage run space show underscore included.py

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.

Summary

1. Retrieve the history using percentage history command. 2. View only a part of history by passing argument to percentage history command.

Summary

3. Save the required lines of code in required order using percentage save command. 4. Use 'percentage run space hypen i' command to run a saved script.

Self assessment 1

• percentage save <filename> 2-5 7 9 hyphen 11
• percentage save <filename> 2 hyphen 11
• percentage save <filename>
• percentage save 2 hyphen 5 7 9 hyphen 11

Self assessment 2

• Percentage execute <script name>
• percentage run hyphen i <script name>
• percentage run <script name>
• percentage execute hyphen i <script name>

And the solutions are

1. 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

1. To run the script we use percentage run space hyphen i <scriptname>

Forum

Fossee Forum

Textbook Companion

Acknowledgment

http://spoken-tutorial.org

For more details, visit this website.

Thank you.