Ventsislav-Yordanov

fruits = ["pineapple", "apple", "lemon", "strawberry", "orange", "kiwi"]
fruits[1]  # apple
fruits[0]  # "pineapple"
fruits[-1] # "kiwi"
fruits[5]  # "kiwi"
fruits[-3] # "strawberry"

# List slicing
fruits[::]    # ["pineapple", "apple", "lemon", "strawberry", "orange", "kiwi"]
fruits[0:2]   # ["pineapple", "apple"]

Ventsislav-Yordanov

# Add values to a list
fruits.append("peach")
fruits # ["pineapple", "apple", "lemon", "strawberry", "orange", "kiwi", "peach"]
fruits = fruits + ["fig", "melon"]
fruits # ["pineapple", "apple", "lemon", "strawberry", "orange", "kiwi", "peach", "fig", "melon"]

# Change values from a list
fruits[0:2] = ["grape", "mango"]
fruits # ["grape", "mango", "lemon", "strawberry", "orange", "kiwi", "peach", "fig", "melon"]

Ventsislav-Yordanov

numbers = [10, 42, 28, 420]
numbers_copy = numbers
numbers_copy[2] = 100
numbers      # [10, 42, 100, 420]
numbers_copy # [10, 42, 100, 420]

ratings = [4.5, 5.0, 3.5, 4.75, 4.00]
ratings_copy = ratings[:]
ratings_copy[0] = 2.0
ratings      # [4.5, 5.0, 3.5, 4.75, 4.0]

Ventsislav-Yordanov

def is_prime(n):
    if n <= 1:
        return False
    elif n <= 3:
        return True
    elif n % 2 == 0 or n % 3 == 0:
        return False
    current_number = 5
    while current_number * current_number <= n:
        if n % current_number == 0 or n % (current_number + 2) == 0:

Ventsislav-Yordanov

# String methods
text = "Data Science" 
text.upper() # "DATA SCIENCE"
text.lower() # "data science"
text.capitalize() # "Data science"

# Lists methods
numbers = [1, 4, 0, 2, 9, 9, 10]
numbers.reverse()
print(numbers) # [10, 9, 9, 2, 0, 4, 1]

Ventsislav-Yordanov

numbers = [10, 30, 55, 40, 8, 30]
text = "Data Science"

numbers.index(8)  # 4
text.index("a")   # 1

numbers.count(30) # 2
text.count("i")   # 1

Ventsislav-Yordanov

import numpy
numbers = numpy.array([3, 4, 20, 15, 7, 19, 0])

Ventsislav-Yordanov

import numpy as np # np is an alias for the numpy package
numbers = np.array([3, 4, 20, 15, 7, 19, 0]) # works fine
numbers = numpy.array([3, 4, 20, 15, 7, 19, 0]) # NameError: name 'numpy' is not defined

Ventsislav-Yordanov

from numpy import array
numbers = array([3, 4, 20, 15, 7, 19, 0]) # works fine
numbers = numpy.array([3, 4, 20, 15, 7, 19, 0]) # NameError: name 'numpy' is not defined
type(numbers) # numpy.ndarray

Ventsislav-Yordanov

# import the "pyplot" submodule from the "matplotlib" package with alias "plt"
import matplotlib.pyplot as plt