Solutions to exercises

3.5. Solutions to exercises #

Exercise 3.1

if 1:
    print('The expression is true')

if 103.51:
    print('The expression is true')

if -1:
    print('The expression is true')

a = True
if a:
    print('The expression is true')

b = -73.445
if b:
    print('The expression is true')

Exercise 3.2

if 5 < 5.1:
    print('The expression is true')

if 5 <= 5:
    print('The expression is true')

if 5.1 > 5.1:
    print('The expression is true')

if 5.1 >= 5.1:
    print('The expression is true')

# "!=" is "not-equals"
if 5 != 5.1:
    print('The expression is true')

Exercise 3.3 (a)

if 5 < 6 and 10 <= 9:
    print("i don't think this is true")

(b)

if not False or True:
    print("it is true?")
else:
    print("it wasn't true?")

Exercise 3.4

def check_number(a):
    if a <= 5:
        print(a, "is less than or equal to 5")
    elif a < 10: 
        # note we don't need to test if it's greater than 5 since the first if already took 
        # care of that for us
        print(a, "is between 5 and 10")
    else:
        print(a, "is greater than or equal to 10")
        
# Testing your function
check_number(1)  
check_number(5)  
check_number(7)
check_number(10)
check_number(15)

Exercise 3.5

def factorial(a):
    # f = our factorial result
    f = 1
    i = 2
    while(i<=a):
        f *= i
        i += 1
    return f
    
print(factorial(4))
print(factorial(2))

Exercise 3.6

# Your code here

s = 0
for i in range(11):
    s += np.sin(i)**2

print("Sum is", s)

Exercise 3.7

s = 0

# Note the range should end at 101!
# It should also start at 1: range(101) will also execute 
# the loop with i=0 (which won't matter here...)
for i in range(1,101):
    s += i

print(s)

Exercise 3.8

# Solution

maxnum=1e6
i=0
while i <= maxnum:
    if i*(i-10)==257024:
        break
    i+=1
    
print(i)

Exercise 3.9

def leap_year(year):
    if year % 4 == 0:
        if year % 100 == 0:
            if year % 400 == 0:
                return True
            return False
        return True
    return False

Exercise 3.10

## Solution
import numpy as np
y = np.array([2, 2, 3, 4, 5, 4, 3, 8, 6, 4]) 

for i in range(1, len(y)-1):
    if y[i-1] < y[i] and y[i+1] < y[i]:
        print('index:', i, '\t value:', y[i])                                  

Exercise 3.11

password = 'practicum123'
tries = 0 

from time import sleep

while True:
    input_pw = input('What is the password?')
    if input_pw == password:
        break
    if (tries+1)%3==0:
        sleep(60+tries**3)
    tries += 1

Solutions to exercises

3.5. Solutions to exercises#

3.5. Solutions to exercises #