Lists and Dictionaries

Lists

list_of_numbers = [1, 2, 3]

list_of_numbers[0]

list_of_numbers[1]

list_of_numbers[2]

list_of_numbers[3]

list_of_numbers[-1]

list_of_numbers[-4]

list_of_numbers[0:2]

0:2

(0:2)

list_of_numbers[0:10]

list_of_numbers[0:100]

list_of_numbers[0:]

list_of_numbers[:]

list_of_numbers[-100:100]

list_of_numbers[0:3:1]

list_of_numbers[0:3:2]

list_of_numbers[::-1]

list_of_numbers + list_of_numbers

list_of_numbers * 5

len(list_of_numbers)

list_of_characters = "hello world"

len(list_of_characters)

list_of_characters[0]

list_of_characters[0:5]

list_of_characters[5:]

list_of_characters[:5] + list_of_characters[5:]

for i in list_of_numbers:
    print(i)

for c in list_of_characters:
    print(c)

if 1 in list_of_numbers:
    print("1 is in the list_of_numbers")

if "hello" in list_of_characters:
    print("hello is part of the string")

Methods

list_of_numbers = [1, 2, 3]

list_of_numbers.append(5)

list_of_numbers

list_of_numbers.insert(3, 4)

list_of_numbers

list_of_numbers.insert(0, 0)

list_of_numbers

list_of_numbers[::-1]

list_of_numbers.sort()

list_of_numbers

names = [
    "JOHN",
    "JANE",
]

for n in names:
    print(n)

for n in names:
    print(n.lower())

for n in names:
    n.lower()
    print(n)

for n in names:
    t = n.lower()
    print(n, t)

def append(list_of_strings):
    list_of_strings.append("World")

l = ["hello"]

append(l)

l

def append(string):
    string = string + "World"

s = "hello"

append(s)

s

Exercise

list_of_numbers = list(range(0, 100))

Dictionaries

myhouse1 = {"type": "apartment", "color": "white", "square_feet": 2000}

myhouse1

myhouse1["color"]

myhouse2 = {'color': 'white', 'square_feet': 2000.0, 'type': 'apartment'}

myhouse2

myhouse1 == myhouse2

animals = []

while True:
    animal = {}
    name = input("Enter the name of a animal: ")
    color = input(f"Enter the color of the animal {name}: ")

    animal["name"] = name
    animal["color"] = color

    animals.append(animal)

    if len(animals) >= 3:
        break

animals

Exercise

SPACES = 10
spaces = (SPACES - len("Name"))
header = f"Name {' ' * spaces} | Color"
print(header)
print(len(header) * "-")
for animal in animals:
    spaces = SPACES - len(animal["name"])
    print(f"{animal['name']} {' ' * spaces} | {animal['color']}")

See string formatting in Python