integer used to store numbers that can later be used in mathematical operations ex: age or temperature
Text(string) Used to store texts lists and words that can later be referenced ex: Name, phone number, or address
Boolean used to store simply of true or false ex: is it raining

Correct way to name variables

incorrect: my highs-coreinthegame or n

too long and can make the code messy
dashes are not allowed when naming variables
spaces are not allowed when naming variables
descriptive enough to easily recall what the variable repersents

correct: highscore or numstudents or israining

short
descriptive
easy to distingush type of variable

3.1.1 Hacks

instructions: Determine what would be the the best variable name and data type for the specific prompt

storing if someones pet is a dog
storing someones birthday
storing the amount of money someone is spending
storing if it is sunny

Homework: write a greeting using variables in python

Naming Conventions

- Must start with a letter or an underscore
- Cannot start with a number 
- Can only have alphanumeric characters or underscores 
- Are case sensitive 
- Cannot be python keywords such as 'else'

myName = "Tara"
print(myName)

Tara

1Tara = "16"

  Cell In[2], line 1
    1Tara = "16"
    ^
SyntaxError: invalid decimal literal

myAge = 16 
myage = 46

print(myAge)
print(myage)

else = 22

Primitive v. Collection Data Types

Primitive Data Types

- int 
- string 
- float 
- boolean 

Collection Data Types

- list 
- dictionary 

myInt = 20

myString = "My name is Tara"

myFloat = 77.29

myBool = False

agesOfMyFriendsList = [16, 20, 15, 12]

print(agesOfMyFriendsList)

agesOfMyFriendsDictionary = { "Tara" : 16, "Tanisha" : 15, "Dylan" : 12, "Tara " : 17}

print(agesOfMyFriendsDictionary["Tara"])

print(agesOfMyFriendsDictionary["Tara "])

Concatenation

‘Joining’ of strings and other types

myFirstName = "Tara"

myLastName = "Sehdave"

print(myFirstName + " " + myLastName)

myFirstInt = 5

mySecondInt = 10 

print(myFirstInt + mySecondInt)

Formatting allows us to display values using pre-decided rules

message = "My first name is {0} and my last name is {1}"

print(message.format("Tara", "Sehdave"))

print(message.format("Tanisha", "Patil"))

x = .77 

message = "Show this as a percentage {0:.0%}"

print(message.format(x))

print(message.format(.25))

message = "The binary value of {0} is {0:b} and the binary value of {1} is {1:b}"

print(message.format(7, 6836))

Conversions

import json

myDictionary = {"A": 1, "B": 2}

print(myDictionary) 

myStringDictionary = json.dumps(myDictionary)

print(myStringDictionary)

myDictionaryRecreated = json.loads(myStringDictionary)

print(myDictionaryRecreated)

# Python Data Types in CB Pseudo Code 

## Primitive Types 

a <-- expression 
- myInt <-- 18
- myString <-- "My name is Tara"
- myFloat <-- 6.8
- myBool <-- False 

# Collection Types 

- myList <-- [1, 2, 3]
- No dictionary 

Data Type Practice

Question 1: Integer Operation

Declare two integer variables, num1Int and num2Int, and assign them values of your choice.
Calculate the sum of num1Int and num2Int
Print the sum

Question 2: Float Operation

Declare two float variables, float1 and float2, and assign them values of your choice.
Calculate the quotient of ‘float1’ and ‘float2’
Print the quotient

Question 3: Format Manipulation

Write a message that equals a sentence with two placeholder variables
Write two strings with two placeholder variables to insert into the message
Print that message

Answers

# Integer Operations

num1Int = 16

num2Int = 12

print(num1Int + num2Int)

# Float Operation

float1 = 1.00

float2 = .75 

print(float1 / float2 )

# Format Manipulation 

message = "{0} is {1} years old"

print(message.format("Tara", "16"))

print (message.format("Sharon", "8"))

print (message.format("Dylan", "80"))

`☆ Topic 3.2 ☆`

☆ Using lists as an abstraction to manage a program's complexity

☆ learn about the lists section of the exam reference sheet

Things to remember

use lists to store multiple elements
data abstraction provides a seperation between abstract parts of a datatype and the actual details of it
it can be created using lists
the exam reference sheets has list notations
the reference sheet has a list structure with index values 1-#of elements in the list. if list index is less that 1 or greater than the list
variables must be bundled together
- strings, characters, words, numbers
give one name to a set of cells

num =[1, 2, 3, 4]
abc = ["a", "b", "c"]
colors = ["red", "green", "blue"]
emptylist = []

#replacing
alist = [10, 20, 30, 40, 50]
blist = [20, 40, 60, 80, 100]
alist = blist

print(alist)
#what will be the output of this code?

%%javascript
# Define an array with elements
const colors = ["Red", "Green", "Blue", "Yellow"];
# Access elements using indexes
const firstColor = colors[0]; // Index 0: "Red"
const secondColor = colors[1]; // Index 1: "Green"
#  Modify an element at a specific index
colors[2] = "Purple"; // Index 2 is changed from "Blue" to "Purple"
# Add a new element to the array
colors.push("Orange"); // Adds "Orange" to the end of the array
# Print elements and their indexes
console.log("First Color:", firstColor);
console.log("Second Color:", secondColor);
console.log("Updated Colors Array:", colors);
# Define a string
const greeting = "Hello, World!";
# Print the string
console.log(greeting);

3.2.3 Data Abstraction

-Manages complexity of data collection -Program easier to develop and maintain -Lists -If a list index is less than 1 or greater than the length of the list, an error message will be produced

How lists help with complexity

-Less variables (like one variable that holds multiple numbers instead of one variable for each number) -Changes number of variables -Consistency -Helps readability

Example

variable1 = 2 variable2 = 5 variable3 = 4

Would be simplified like this!

scores = [2, 5, 4]

Activity - Turn this into a list!

variable1 = 7 variable2 = 9 variable3 = 2 variable4 = 8

Data Abstraction 2

3.1.1 - What are variables

Sharon Kodali

different data types to store variables in