diff -r ab748264f726 -r 2b88724a7ee0 additional_ipython.rst --- a/additional_ipython.rst Thu Oct 07 14:15:30 2010 +0530 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,322 +0,0 @@ -.. Author : Nishanth - Internal Reviewer 1 : - Internal Reviewer 2 : - External Reviewer : - -.. Prerequisites: Embellinshing plots - -Script -====== - - -Hello friends and welcome to the tutorial on Additional Features of IPython - -{{{ Show the slide containing title }}} - -{{{ Show the slide containing the outline slide }}} - -In this tutorial, we shall look at additional features of IPython that help us -to retreive the commands that we type on the interpreter and then save them -into a file and run it. - -Let us start ipython with pylab loaded, by typing -:: - - $ ipython -pylab - -on the terminal - -{{{ shit to terminal and type ipython -pylab }}} - -We shall first make a plot and then view the history and save it. -:: - - x = linspace(-2*pi, 2*pi, 100) - plot(x, xsinx(x)) - -xsin(x) is actually x * sin(x) -:: - - plot(x, x*sin(x)) - plot(x, sin(x)) - xlabel("x") - ylabel("$f(x)$") - title("x and xsin") - -We now have the plot. Let us look at the commands that we have typed in. The -history can be retreived by using =%hist= command. Type -:: - - %hist - -As you can see, it displays a list of recent commands that we typed. Every -command has a number in front, to specify in which order and when it was typed. - -Please note that there is a % sign before the hist command. This implies that -%hist is a command that is specific to IPython and not available in vannila -Python interpreter. These type of commands are called as magic commands. - -Also note that, the =%hist= itself is a command and is displayed as the most -recent command. This implies that anything we type in is stored as history, -irrespective of whether it is command or an error or IPython magic command. - -If we want only the recent 5 to be displayed, we pass the number as an argument -to =%hist= command. Hence -:: - - %hist 5 - -displays the recent 5 commands, inclusive of the =%hist= command. -The default number is 40. - -{{{ Pause here and try out the following exercises }}} - -%% 1 %% Read through the %hist documenatation and find out how can we list all - the commands between 5 and 10 - -{{{ continue from paused state }}} - -As we can see from =%hist= documentation, -:: - - %hist 5 10 - -displays the commands from 5 to 10 - -Now that we have the history, we would like to save the required line of code -from history. This is possible by using the =%save= command. - -Before we do that, let us first look at history and identify what lines of code -we require.Type -:: - - %hist - - -{{{ point to the lines }}} - -The first command is linspace. But second command is a command that gave us an -error. Hence we do not need seconf. The commands from third to sixth are -required. The seventh command although is correct, we do not need it since we -are setting the title correctly in the eigthth command. - -So we need first third to sixth and the eigthth command for our program. -Hence the syntax of =%save= is -:: - - %save /home/fossee/plot_script.py 1 3-6 8 - -{{{ point to the output of the command }}} - -The command saves first and then third to sixth and eighth lines of code into -the specified file. - -The first argument to %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. - -{{{ goto the file and open it and show it }}} - -{{{ Pause here and try out the following exercises }}} - -%% 2 %% change the label on y-axis to "y" and save the lines of code - accordingly - -{{{ continue from paused state }}} - -we use the command =ylabel= on interpreter as -:: - - ylabel("y") - -and then do -:: - - %save /home/fossee/example_plot.py 1 3-6 10 - -Now that we have the required lines of code in a file, let us learn how to run -the file as a python script. - -We use the IPython magic command =%run= to do this. Type -:: - - %run -i /home/fossee/plot_script.py - -The script runs but we do not see the plot. This happens because we are running -a script and we are not in interactive mode anymore. - -Hence on your terminal type -:: - - show() - -to show the plot. - -{{{ Pause here and try out the following exercises }}} - -%% 3 %% Use %hist and %save and create a script that has show in it and run it - to produce and show the plot. - -{{{ continue from paused state }}} - -We first look at the history using -:: - - %hist 20 - -Then save the script using -:: - - %save /home/fossee/show_included.py 1 3-6 8 10 13 - %run -i /home/fossee/show_included.py - -We get the desired plot. - -The reason for including a -i after run is to tell the interpreter that if any -name is not found in script, search for it in the interpreter. 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. - -{{{ Pause here and try out the following exercises }}} - -%% 4 %% Run the script without using the -i option. Do you find any difference? - -{{{ continue from paused state }}} - -We see that it raises nameerror saying the name linspace is not found. - -{{{ Show summary slide }}} - -This brings us to the end of the tutorial. -we have looked at - - * Retreiving history using =%hist= command - * Vieweing only a part of history by passing an argument to %hist - * saving the required lines of code in required order using %save - * using %run -i command to run the saved script - -{{{ Show the "sponsored by FOSSEE" slide }}} - -#[Nishanth]: Will add this line after all of us fix on one. -This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India - -Hope you have enjoyed and found it useful. -Thankyou - -Questions -========= - - 1. How do you retrieve the recent 5 commands - - a. ``%hist`` - #. ``%hist -5`` - #. ``%hist 5`` - #. ``%hist 5-10`` - - Answer: ``%hist 5`` - - 2. If there were 20 commands typed and ``%hist`` is used. How many commands - will be displayed. - - a. 10 - #. 20 - #. 21 - #. 19 - - Answer: 21 - - 3. is ``%hist`` considered as a command - - a. True - #. False - - Answer: True - - 4. how do you retreive the commands from 20 to 50 (inclusive of 20 and 50) - - a. ``%hist 20 50`` - #. ``%hist 19 50`` - #. ``%hist 19 51`` - #. ``%hist 21 50`` - - Answer: ``%hist 20 50`` - - 5. What does the ``%hist 2 5 7`` command do - - a. lists the second, fifth and seventh commands - #. lists the commands from 2 to 5 and the seventh command - #. raises an error - #. lists the commands 2 to 7 - - Answer: raises an error - - 6. How many commands are displayed when lot of coomands were typed and - ``%hist`` is used. - - a. 20 - #. 10 - #. 50 - #. 40 - - Answer: 40 - - 7. How do you save the lines 2 3 4 5 7 9 10 11 - - a. ``%save filepath 2-5 7 9-11`` - #. ``%save filepath 2-11`` - #. ``%save filepath`` - #. ``%save 2-5 7 9 10 11`` - - Answer: ``%save filepath 2-5 7 9-11`` - - 8. You are working in /home/user. Where is the file saved when you do - ``%save hello.py 1-3`` - - a. /home/user/hello.py - #. /hello.py - #. /home/hello.py - #. /home/user/ipython/hello.py - - Answer: /home/user/hello.py - - 9. Which lines are saved by the command ``%save filepath 2-5 7 1`` and in - which order - - a. 2 3 4 5 7 1 - #. 1 2 3 4 5 6 7 - #. 2 5 7 1 - #. 1 2 5 7 - - 10. What happens when ``%save filepath line_numbers`` is used and a file - already exists in that path. - - a. It is overwritten - #. The commands are added to the file - #. It raises an error - #. A prompt to confirm overwriting is displayed - - Answer: A prompt to confirm overwriting is displayed - - 11. Read through the documentation of ``%hist`` and find its alternative name - - Answer: ``%history`` - - 12. Are ``%run /home/user/saved.py`` and ``%run /home/user/saved`` the same - - a. Yes - #. No - - Answer: Yes - - 13. The file hello.py contains only one command ``x = x + 1``. What happens - when you do ``%run hello.py`` - - Answer: Raises a nameerror - - 14. The file hello.py contains only one command ``x = x + 1``. If value of x - is 5 and what does ``%run -i hello.py`` do. - - a. raises an error - #. increments value of x by 1 - #. Does nothing - - Answer: increments the value of x by 1