Conditional Statements - Answer Key

Exercise 1

1. Create boolean logic to test whether x is NOT equal to 67.

# Test if x is not equal to 15
x != 67

True

2. Create an if statement that evaluates if x is NOT equal to 67 and if the number is not 67 then have it print “x is NOT 67.”

# Check if x is NOT equal to 67
if x != 67:
    # If true, then print out 'x is NOT 67'
    print('x is NOT 67')

x is NOT 67

Exercise 2

1. Set my_name to be equal to Noor. Using the in operator and an if statement, check if there is an “o” within my_name. If true, have it return “I have found an ‘o’.”.

Hint: You may want to consider using single/double quotations for the entire print statement and using the other type of quotation mark around the “o”. Alternatively, you can look into escaping characters in Python.

We can do this with mixing our quotation marks. We can put the larger print statement within "" and the o within ''.

# Set my_name equal to "Noor"
my_name = "Noor"

# Check if "o" is in my_name, which is now set to "Noor"
if "o" in my_name:
    # If true, then print out "I have found an 'o'."
    print("I have found an 'o'.")

I have found an 'o'.

Alternatively, you could have tried escaping the double quotes. When you escape a character, you precede the character with a \ and this tells Python to treat the next character as a literal character rather than the special character that closes a string.

# Set my_name equal to "Noor"
my_name = "Noor"

# Check if "o" is in my_name, which is now set to "Noor"
if "o" in my_name:
    # If true, then print out "I have found an 'o'."
    print('I have found an \'o\'.')

I have found an 'o'.

2. We can see that there are two “o”s in Noor. So, one might expect there to be two “I have found an ‘o’.” statements, but we only see one. Why is this?

This happens because Python is looking to evaluate whether it finds an “o” within my_name, “Noor”. Once it finds the “o”, it evaluates the conditional code block and exits the if statement. It does not continue to evaluate each position in “Noor”. Since the condition is “Is there an”o” in “Noor?” and once it reaches the first “o”, that resolves as True. There is no idea of “double True”.

Exercise 3

1. Create an if statement to evaluate whether x is between 5 and 10, inclusive of both 5 and 10. If so, have Python print out “x is between 5 and 10, inclusively”.

# Check if x is greater than of equal to 5 AND if x is less than of equal to 10
if x >= 5 and x <= 10:
    # If true, print out this message
    print("x is between 5 and 10, inclusively")

2. Extend this same conditional to if x is not between 5 and 10, inclusively, but is above 10, then Python it print out “x is greater than 10”.

# Check if x is greater than of equal to 5 AND if x is less than of equal to 10
if x >= 5 and x <= 10:
    # If true, print out this message
    print("x is between 5 and 10, inclusively")
# Otherwise, check if x is greater than 10
elif x > 10:
    # If true, print out this message
    print("x is greater than 10")

x is greater than 10

3. Extend this same conditional to if x is not between 5 and 10, inclusively, and also not above 10, then have Python return “x is less than 5”.

# Check if x is greater than of equal to 5 AND if x is less than of equal to 10
if x >= 5 and x <= 10:
    # If true, print out this message
    print("x is between 5 and 10, inclusively")
# Otherwise, check if x is greater than 10
elif x > 10:
    # If true, print out this message
    print("x is greater than 10")
# Otherwise
else:
    # Print out this message
    print("x is less than 5")  

x is greater than 10