Get User Input
Python has a built-in function called input that will prompt the user and give us back the result, which can be stored into a variable.
print("Please enter your full name")
name = input()
name = input("Please enter your full name: ")
Conditional Statements
Conditional logic using if statements represent different paths a program can take based on some type of comparison of input.
if name == "Mark Zuckerberg":
print("You work at Facebook")
elif name == "Jack Dorsey":
print("You work at Twitter")
elif name == "Sundar Pichai":
print("You work at Google")
else:
print("Not enough data")
Truthy & Falsy
All conditional checks resolve to either True or False
x = 1
x is 1 # True
x is 0 # False
We can call values that resolve to True as “truthy”, and values that resolve to False as “falsy”. Besides False, other things that are naturally falsy include: empty objects, empty strings, None and zero (0).
Comparison Operators
Consider we are comparing two variables, x and y. Ex. x > y
Logical Operators
The following operators can be used to make Boolean Logic comparisons or statements:
is vs. “==”
In Python, == and is are very similar in functionality, but they are not the same.
x = 1
x == 1 # True
x is 1 # True
x = \[1, 2, 3\] # A list of numbers.
y = \[1, 2, 3\]
x == y # True
x is y # False
z = y
y is z # True
Nested Conditionals
if statement inside an if statement
Scratchpad file
Show file detail
# = assignment
# == compare
# name = input("Please enter your name: ")
# if name != "Mark Zuckerberg":
# print("You don't belong to Facebook")
# elif name == "Jack Dorsey":
# print("You don't belong to Twitter")
# elif name == "Sundar Pichai":
# print("You don't belong to Google")
# else:
# print("Whatever!")
# Operators
# == equal to
# != not equal to
# > great than
# < less than
# >= greater than or equal to
# <= less than or equal to
# age = input("Please enter your age: ")
# age = int(age)
# if age >= 21:
# print("You are allowed to drink")
# elif age >= 65:
# print("You get drinks for free")
# else:
# print("Sorry you can't drink!")
# if items > 20:
# print("Oh, you have a lot of stuff")
# elif items < 10:
# print("Too bad, you can buy more.")
# else:
# print("That's perfect")
# Truthiness
# Falsyness
# logged\_in = "someuser@gmail.com"
# if logged\_in:
# print("You have logged in, see the content")
# else:
# print("Sorry, please login to check")
# Logical Operations
# and
# or
# not
# age = input("Please enter your age: ")
# age = int(age)
# if age >= 21 and age < 65:
# print("You are allowed to drink")
# elif age >= 65:
# print("You get drinks for free")
# elif age >= 18 and age < 21:
# print("You can enter but you cannot drink")
# else:
# print("Sorry you can't drink, you're too young!")
# NAME
# city = "mumbai"
# if city == "mumbai" or city == "bangalore":
# print("You live in a tier 1 city")
# if city == "pune" or city == "jaipur":
# print("You live in a tier 2 city")
# if not city == "mumbai":
# print("You are out of Mumbai")
# and -> LHS and RHS TRUE
# 0, None, "" -> Falsy values
#
# username = "mark@fb.com"
# if not username:
# print("Hello my friend")
# else:
# print("You are not welcome")
# is vs ==
# == - it checks for the value.
# is - checks whether it is the same thing in memory
# Nested conditionals
age = input("How old are you? ")
if age:
age = int(age)
if age >= 21 and age < 65:
print("You are allowed to drink")
elif age >= 65:
print("You get drinks for free")
elif age >= 18 and age < 21:
print("You can enter but you cannot drink")
else:
print("Sorry you can't drink, you're too young!")
else:
print("Please enter a valid age!")
Scratchpad file – loops
# For loop
# numbers = \[100, 20, 2, 24, 45\]
# for number in numbers:
# num = (number / 2) \* 2.3
# print(f"The value of this number is {num}")
# name = "Stephen"
# for char in name:
# print(char)
# Iterable - range of numbers, strings, lists, dictionaries
# my\_time = 4
# for time in \[1, 2, 3, 4\]:
# print("Happy Birthday!")
# my\_time = time
# print(my\_time)
# for item in iterable\_object:
# do something
# for num in 10:
# print("Hello World")
# range(20) -> 0
# range(10, 21) ->
# range(0, 21, 2)
# range(10, 1, -1)
# range(start = 0, end, step = 1)
# for time in range(0, 6):
# print("JUMP")
# rant = input("How many times do you want to scream? ")
# rant = int(rant)
# for i in range(0, -50, -1):
# print("CLEAN YOUR ROOM!!!!")
# if i == 5:
# print("OKAY OKAY, I'll do it!")
# 1 - 20 ->
# odd - "Fizz is odd"
# even - "Fizz is even"
# 5, 16, print("FizzBuzz")
# num % 2 != 0 (odd)
# for num in range(1, 21):
# if num == 5 or num == 16:
# print(f"{num}: FizzBuzz")
# elif num % 2 == 0:
# print(f"{num}: Fizz is even")
# elif num % 2 != 0:
# print(f"{num}: Fizz is odd")
# While loop
# password = input("Please enter your secret password: ")
# while password != "tesla1":
# print("INCORRECT PASSWORD! GET LOST!")
# password = input("Please enter the correct password: ")
# print("CORRECT! Hello...")
# num = 10
# i = 1
# while i <= num:
# print(f"{i}: Hello World")
# i = i + 1
# break statement
# password = input("Please enter your secret password: ")
# while password != "tesla1":
# if password == "GODMODE":
# break
# print("INCORRECT PASSWORD! GET LOST!")
# password = input("Please enter the correct password: ")
# print("CORRECT! Hello...")
# num = 30
# i = 1
# j = 1
# while i <= num:
# if i == 10:
# while j < 5:
# print("Hello world!")
# j += 1
# print(f"{i}: Hello World")
# i = i + 1
# Exercise 1
# 0 : 20
# 0 : -30
# 30 : -30
# Exercise 2: Rock paper scissor
# best out of three
# player1\_wins = 3
# player2\_wins = 0
# winning\_score = 3
# while player1\_wins >= 3 or player2\_wins >= 3:
# print("Player1 wins")
# player1\_wins += 1
# # code...............
# if player1\_wins > player2\_wins:
# print("PLAYER 1 is the victor!")
# else:
# print("PLAYER 2 is the vector!")
# Data Structures -> Data Types
# int, strings, None, List, Dicts
# data structure
# list = \[1, "hello", 3, 4, True, None, \[1, 2, 3, 4\], \[1, 2, 3, 5.5555\]\]
# shopping\_cart = \["apples", "cucumbers", "phone"\]
# results = \[
# \["One", "Metallica", 3.49, 1000000, "Song performed by metallica from the album, St. Anger",
# "bucket3.aws.amazonaws.com/photo-gal/11134/32/thumbnail\_32.png"\]
# \["Fade to black", "Metallica", 3.49, 1000000, "Song performed by metallica from the album, St. Anger",
# "bucket3.aws.amazonaws.com/photo-gal/11134/32/thumbnail\_32.png"\]
# \["Fade to black", "Metallica", 3.49, 1000000, "Song performed by metallica from the album, St. Anger",
# "bucket3.aws.amazonaws.com/photo-gal/11134/32/thumbnail\_32.png"\]
# \]