class_week_2.py

# -*- coding: utf-8 -*-
"""
Created on Thu Jan 17 11:25:18 2019

@author: mpodebradska2
"""
# Exercise 6

my_list = [1, 2, 3]

def mean(sequence):
    '''Calculates the arithmetic mean of a sequence from a list'''
    return sum(sequence)/len(sequence)

print("Ecercise 6: ", mean(my_list))
    

# Exercise 2
my_list = [20.0, 22.0, 19.0]
new_list = []

for item in my_list:
    new_list.append(item*5)

print(new_list)

# Exercise 8
my_list = [1, 2, 3]

def mean(sequence):
    '''Calculates the arithmetic mean of a sequence from a list'''
    return sum(sequence)/len(sequence)

def square_root(sequence):
    var_mean = mean(sequence)
    squared_errors = []
    for i in sequence:
        squared_errors.append((i - var_mean) ** 2)
    
    sse = sum(squared_errors)
    n = len(sequence)
    return(sse / (n - 1)) ** (1 / 2)
    
print("Ecercise 8: ", square_root(my_list))

# Indexing
new_list2 = [1, 2, [3, 4], "Bob"]

print(my_list[-1])
print(new_list2[2][1])

# Slicing some_list[start:stop:step]

my_list2 = list(range(7))
print(my_list2)

print(my_list2[0::2])

# Exercise 5

my_list3 = list(range(1, 10, 2))

def maximum(sequence):
    '''Gets a max value from a list'''
    new_sequence = sequence.copy()
    new_sequence.sort
    return new_sequence[-1]

def minimum(sequence):
    '''Gets a min value from a list'''
    new_sequence = sequence.copy() # we are copying because we don't want to mutate the original list as we sort in the next line
    new_sequence.sort
    return new_sequence[0]

print(maximum(my_list3))
print(minimum(my_list3))

# Conditionals

x = 10

if x < 5:
    print("less than 5")
elif x < 10:
    print("less than 10")
else:
    print("greater or equal to 10")

# Ecercise 6

def even_odd(number):
    if number % 2 == 0:
        print("Even")
    else:
        print("Odd")

even_odd(100)

def is_even(number):
    return number % 2 == 0

print(is_even(9))

# Exercise 7

ages = [20, 20, 21, 43, 33, 27, 19, 23, 22, 29]
ages2 = list(range(100))

def younger_than_25(sequence):
    new_list = []
    for i in sequence:
        if i < 25:
            new_list.append(i)
    print(new_list)
    return len(new_list)

younger_than_25(ages2)

# Exercise 8

new_list_4 = list(range(1, 101))

squares = [a ** 2 for a in new_list_4]
print(squares)