# Notes for Unit 2 - Illustrative programs ## Program 1 ## Source Code ```python print("Enter two values to swap") a = int(input()) b = int(input()) # using a temporary variable print("Swapping using temporary variable...") t = a a = b b = t print("Value of a is {a} and\nValue of b is {b}".format(a=a, b=b)) # using XOR operator, eliminating the need for 3rd variable print("Swapping using XOR operator...") a = a ^ b b = a ^ b a = a ^ b print("Value of a is {a} and\nValue of b is {b}".format(a=a, b=b)) def swap_func(): global a, b print("swap_func function called") a, b = b, a swap_func() # a and b values get swapped again print("Value of a is {a} and\nValue of b is {b}".format(a=a, b=b)) ``` ## Sample Output ![out1](https://i.imgur.com/LNV3850.jpg) ## Demo run `python3 swap.py` in ## Program2 ## Source Code ```python def circulate(a, b, c): i = 3 while i: t = a a = b b = c c = t print(a, b, c) i -= 1 print("Enter 3 values") a, b, c = input().split() print() circulate(a, b, c) def circulate_list(alist): i = len(alist) while i: first = alist.pop(0) alist.append(first) print(*alist, sep=", ") i -= 1 alist = input("enter multiple values\n").split() print() circulate_list(alist) ``` ## Sample Output ![out2](https://i.imgur.com/iSSVEUi.jpg) ## Demo run `python3 circulate.py` in ## Program 3
QuestionAnswer

Coordinate Geometry Terms


Coordinate Geometry Definition - It is one of the branches of geometry where the position of a point is defined using coordinates.


What are the Coordinates?


What are the Coordinates?


Coordinates are a set of values which helps to show the exact position of a point in the coordinate plane.

Coordinate Plane Meaning - A coordinate plane is a 2D plane which is formed by the intersection of two perpendicular lines known as the x-axis and y-axis.


What is the Distance Formula?

What is the Distance Formula?


It is used to find the distance between two points situated in A(x1,y1) and B(x2,y2)


What is the most logical way to represent a cartesian point in Python?


A. Use two variables, for e.g. x1 and y1 or x2 and y2

B. Use a single tuple variable

C. None of the above

Choice B.

Tuple is the logical way of representing a point in Python.

What is the syntax for defining a point (3, 4) as a tuple in Python?


A. (3, 4)

B. tuple(3, 4)

C. Both the above are valid

Choice C.


(3, 4) and tuple(3, 4) are equivalent to each other.


How can you deconstruct a tuple that represents a point?


How do you deconstruct a tuple?


If

pointA = (6, 8) # construction


then

x1, y1 = pointA # deconstruction

print(x1, y1) # 6, 8

x1, y1, x2, y2 = (1, 2, 3, 4)


What is the value of x1 and y2?

1 and 4.

What is the distance between (4, 0) and (0, 0)?


4


d = (x1 - x2)

= 4 - 0

= 4

What is the distance between (4, 3) and (4, 0)?



3


d = (x1 - x2) + (y1 - y2)

= (4 - 4) + (3 - 0)

= 0 + 3

= 3

What is the distance between (4, 3) and (0, 0)?


Using previous formula, we get


d = (x1 - x2) + (y1 - y2)

= (4 - 0) + (3 - 0)

= 4 + 3

= 7


But we know from https://www.mathsisfun.com/algebra/distance-2-points.html



If (x1 - x2) + (y1 - y2) is giving a higher value than what is correct,


What can the distance formula be?

Why not square the x component and square the y component, and then reduce it down by using square root?


The distance formula is as follows:


What is the distance between (2, -1) and (5, 3)?

Are you confident of writing the code for Distance between Two Points?




Test yourself at http://j.mp/twoPointsCC
## Source Code ```python from math import sqrt def distance_between(pointA, pointB): x1, y1 = pointA x2, y2 = pointB distx = x1 - x2 disty = y1 - y2 return sqrt(distx**2 + disty**2) # main program # tuple packing allows for assigning # multiple inputs in one statement print("Enter coordinates for Point A") pointA = int(input()), int(input()) print("Enter coordinates for Point B") pointB = int(input()), int(input()) print("distance between {0} and {1} is {2}" .format(pointA, pointB, distance_between(pointA, pointB)) ) ``` ## Sample Output ![out3](https://i.imgur.com/jGNMaNN.jpg) ## Demo run `python3 distance.py` in ## Teaching Assets | item | link | remarks | | ---------------------------- | -------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- | | Video capture | | demonstrates how to use Memcode and CyberDojo and Slides | | Memcode cards | [https://www.memcode.com/courses/2288/](https://www.memcode.com/courses/2288/review) | useful for classroom and personal review | | CyberDojo link | | The super simple testing framework for capturing incremental coding sessions | | Google Slides | [PDF version](https://github.com/kgisl/pythonFDP/blob/master/units/Unit%202%20-%20illustrative%20programs.pdf) | Or PPTx file is better? | | Auto-generated documentation | [distance\_between](https://kgisl.gitbook.io/lab3003/docs#distance_between) doctstring documentation | consolidates all docstrings in one place ([docs/README.md](https://kgisl.gitbook.io/lab3003/docs)) in the repo | ## Bonus Material ### Swap There are actually 4 ways to do it. Please find all of them. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://kgisl.gitbook.io/lab3003/units/unit2-illustrative2-notes.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.