st-scripts: comparison getting_started_with

equal deleted inserted replaced

-:d95288e57cfc
+:8835b2c071e6
 Hello and welcome to the tutorial getting started with ``for`` loop.
 {{{ switch to next slide, outline slide }}}
-In this tutorial we will learn about ``for`` loops in python, and also cover
+In this tutorial we will learn about ``for`` loops in python, and also
-the basics of indenting code in python.
+learn how to write blocks of code in Python.
 .. #[Nishanth]: Instead of saying basics of indenting code,
 say How to define code blocks in Python
 {{{ switch to next slide, about whitespaces }}}
 In Python whitespace is significant, and the blocks are visually
-separated rather than using braces or any other mechanisms for
+separated.
-defining blocks. And by this method Python forces the programmers to
-stick on to one way of writing or beautifying the code rather than
-debating over where to place the braces. This way it produces uniform
-code than obscure or unreadable code.
 .. #[nishanth]: Simply tell how blocks are defined in python.
 The details like braces are not used and its
 advantages like neat code can be told after completely
 explaining the indentation
 .. #[Amit]: Do you want to do that here. May be its better to talk about
 this after some initiation into the idea of blocks.
-A block may be defined by a suitable indentation level which can be
+The best practice is to indent the code using four spaces.
-either be a tab or few spaces. And the best practice is to indent the
-code using four spaces.
 .. #[Nishanth]: Even this detail may be skipped. Simply say use 4 spaces
 for indentation. Do that while typing so that they can
 actually see what is being typed.
 Now let us move straight into ``for`` loop.
 {{{ switch to next slide, problem statement of exercise 1 }}}
 Write a for loop which iterates through a list of numbers and find the
-square root of each number. Also make a new list with the square roots
+square root of each number.
-and print it at the end.
+::
+numbers are 1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916
 .. #[nishanth]: making new list with square roots induces extra complication
 like appending which has no use case here
-::
-numbers are 1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916
 .. #[Nishanth]: The problem focuses more on square root and creation
 of list. The problem must be simple and focusing on
 nothing more but the indentation and for loop.
 May be change the problem to print squares than to
 {{{ open the text editor and paste the following code there }}}
 ::
 numbers = [1369, 7225, 3364, 7056, 5625, 729, 7056, 576, 2916]
-square_roots = []
 for each in numbers:
-sq_root = sqrt(each)
+print "Square root of", each, "is", sqrt(each)
-print "Square root of", each, "is", sq_root
+print "This is not in for loop!"
-square_roots.append(sq_root)
-print
-print square_roots
 ..  numbers = [1, 12, 3, 4, 21, 17]
 for each in numbers:
 print each, each * each
 .. #[Nishanth]: you don't have to use the -i option here
 {{{ run the script }}}
-So that was easy! We didn't have to find the length of the string nor
+So that was easy! All what we did was iterate over the list element by
-address of each element of the list one by one. All what we did was
+element and then use the element for calculation. Note that here we
-iterate over the list element by element and then use the element for
+used two variables. One the variable ``numbers``, which is a list,
-calculation. Note that here we used three variables. One the variable
+another one ``each``, which is the element of list under consideration
-``numbers``, which is a list, another one ``each``, which is the
+in each cycle of the ``for`` loop. The variable names can be chosen by
-element of list under consideration in each cycle of the ``for`` loop,
+you.
-and then a variable ``sq_root`` for storing the square root in each
-cycle of the ``for`` loop. The variable names can be chosen by you.
 .. #[Nishanth]: The details like we didn't have to find the length
 are relevant for people who have programmed in C or
 other languages earlier. But for a newbie it is more
 of confusing extra info. That part may be skipped.
 variable sq_root can also be avoided. let it be more
 about "each", "numbers" and "for". no other new names.
 {{{ show the script which was created }}}
-Note that three lines after ``for`` statement, are indented using four
+Note that the lines after ``for`` statement, is indented using four
 spaces.
-{{{ highlight the three lines after for statement }}}
+{{{ highlight the line after for statement }}}
-It means that those three lines are part of the for loop. And it is
+It means that line is part of the for loop. And it is a block of code,
-called a block of statements. And the seventh line or the immediate
+although it is only a single statement in the block. And the fourth
-line after the third line in the ``for`` loop is not indented,
+line or the immediate line after the ``for`` block is not indented,
-{{{ highlight the seventh line - the line just after for loop }}}
+{{{ highlight the fourth line - the line just after for loop }}}
 it means that it is not part of the ``for`` loop and the lines after
 that doesn't fall in the scope of the ``for`` loop. Thus each block is
 separated by the indentation level. Thus marking the importance of
 white-spaces in Python.
 ::
 7225, 3268, 3364, 2966, 7056, 5625, 729, 5547, 7056, 576, 2916
 {{{ switch to next slide, problem statement of second problem in
-solved exercie}}}
+solved exercise}}}
 Now let us try a simple one, to print the square root of numbers in
 the list. And this time let us do it right in the IPython
 interpreter.
 for each in numbers:
 and now you will notice that, as soon as you press the return key
 after for statement, the prompt changes to four dots and the cursor is
 not right after the four dots but there are four spaces from the
-dots. The four dots tell you that you are inside a block. Now type the
+dots. Please note that IPython automatically indents the block. The
-rest of the ``for`` loop,
+four dots tell you that you are inside a block. Now type the rest of
+the ``for`` loop,
 .. #[Nishanth]: Tell that IPython does auto indentation.
 ::
-sq_root = sqrt(each)
+print "Square root of", each, "is", sqrt(each)
-print "Square root of", each, "is", sq_root
 Now we have finished the statements in the block, and still the
 interpreter is showing four dots, which means you are still inside the
 block. To exit from the block press return key or the enter key twice
 without entering anything else. It printed the square root of each
 number in the list, and that is executed in a ``for`` loop.
-Now, let us generate the multiplication table of 10 from one to
+Now, let us find the cube of all the numbers from one to ten. But this
-ten. But this time let us try it in the vanilla version of Python
+time let us try it in the vanilla version of Python interpreter.
-interpreter.
 Start the vanilla version of Python interpreter by issuing the command
 ``python`` in your terminal.
 {{{ open the python interpreter in the terminal using the command
 for i in range(1,11):
 and press enter once, and we will see that this time it shows four
 dots, but the cursor is close to the dots, so we have to indent the
-block. So enter four spaces there and then type the following
+block. The vanilla version of Python interpreter does not indent the
+code automatically. So enter four spaces there and then type the
+following
 ::
+print i, "cube is", i**3
-print "10 x",i,"=",i*10
 Now when we hit enter, we still see the four dots, to get out of the
 block, hit enter once again
 .. #[Nishanth]: Here also the overhead on print can be reduced.
 Okay! so the main thing here we learned is how to use Python
 interpreter and IPython interpreter to specify blocks. But while we
 were generating the multiplication table we used something new,
 ``range()`` function. ``range()`` is an inbuilt function in Python
 which can be used to generate a ``list`` of integers from a starting
-number to an ending number. Note that the ending number that you specify
+number to an ending number. Note that the ending number that you
-will not be included in the ``list``.
+specify will not be included in the ``list``.
 .. #[Nishanth]: Show some examples of range without the step argument
 May be give an exercise with negative numbers as arguments
 Now, let us print all the odd numbers from 1 to 50. Let us do it in
 our IPython interpreter for ease of use.
-{{{ switch focus to ipython interpreter }}}
 {{{ switch to next slide, problem statement of the next problem in
 solved exercises }}}
-Print the list of odd numbers from 1 to 50. It will be better if
+{{{ switch focus to ipython interpreter }}}
-you can try it out yourself.
+The problem can be solved by just using the ``range()`` function.
-It is a very trivial problem and can be solved as,
+It can be solved as,
 ::
 print range(1,51,2)
 This time we passed three parameters to ``range()`` function unlike

changeset 206	8835b2c071e6
parent 203	846d71a4e915