4.2. Exercises

4.2.1. Exercise 1

In this exercise we want to determine if a number is positive (>0) or not. Write a function that will return a value based on whether the number is positive or not. Then try it out with different arguments.

# write the function here

# write the function calls here

4.2.2. Exercise 2

Write a function that will receive an arbitrary number of integer arguments and will compute their average. Test it with different numbers of arguments.

# write the function here

# write the function calls here

4.2.3. Exercise 3

Suppose that we have the following piece of code:

def find_square(x):
return x**2

print(find_square(2))

Do you think it will run? Explain your reasoning.

# write your answer as a comment here

4.2.4. Exercise 4

Suppose that we have the following piece of code:

def function_xyz(x,y,z):
    x = 5
    
    if(y>0):
        a = x*3
    else:
        b = z*2
    
    return a*b


print(function_xyz(1,2,3))
print(function_xyz(1,-2,3))
print(function_xyz(1,0,3))

Do you think any of the function calls will execute correctly? Explain your reasoning.

# write your answer as a comment here

4.2.5. Exercise 5

Suppose that we have the following piece of code:

def function_xyz(x,y,z):
    x = 5
    
    if(y>0):
        a = x*3
    if(z>0):
        b = z*2
    
    return a*b


print(function_xyz(1,2,3))
print(function_xyz(1,-2,-3))

Do you think any of the function calls will execute correctly? Explain your reasoning.

# write your answer as a comment here

4.2.6. Exercise 6

Remember the Christmas tree we were trying to build on exercise 6 of chapter 3? Now we want to be more flexible and based on our available space build different-sized Christmas trees, not only with 5 stars. Modify the following code so that it takes different numbers, and using them builds Christmas trees of different sizes. (You need to substitute only the question marks.)

def build_christmas_tree( ? ):
    for i in range(0, ? ):
        for j in range(0,(i+ ?)):
            if j>=(?-(i+1)):
                if (j%2==0 and i%2==0) or (j%2==1 and i%2==1):
                    print('*', end='')
                else:
                    print(' ', end='')
            else:
                print(' ', end='')
        print(' ')

  Cell In[8], line 1
    def build_christmas_tree( ? ):
                              ^
SyntaxError: invalid syntax

# define a variable for the length
# call the function