Arithmetic, Relational & Boolean Operations (AQA GCSE Computer Science)

# -----------------------------------------------------------------------
# Arithmetic operators #1
# -----------------------------------------------------------------------
# Get the user to input a number
user_input = int(input("Enter a number: "))

# if the remainder of the number divided by 2 is 0, the number is even
if user_input % 2 == 0:
    print("The number is even.")
else:
    print("The number is odd.")

# -----------------------------------------------------------------------
# Arithmetic operators #2
# -----------------------------------------------------------------------
# Get the radius from the user
radius = float(input("Enter the radius of the circle: "))

# Calculate the area of the circle
area = 3.14159 * radius ** 2

# Display the calculated area
print("The area of the circle with radius",radius,"is",area)

# ------------------------------------------------------------------------
# Arithmetic operators #3
# ------------------------------------------------------------------------
# Set the score to 0
score = 0

# Loop 5 times
for x in range(5):
    num1 = int(input("Enter the first number: "))
    operator = input("Enter the operator (+, -, *): ")
    num2 = int(input("Enter the second number: "))
    user_answer = int(input("What is "+str(num1)+str(operator)+str(num2)+"? "))

# Check the answer and update the score
    if operator == '+':
        correct_answer = num1 + num2
    elif operator == '-':
        correct_answer = num1 - num2
    elif operator == '*':
        correct_answer = num1 * num2

    if user_answer == correct_answer:
        score = score + 1
    else:
      print("Sorry that's incorrect.")

print("Your score is:", score)

# -----------------------------------------------------------
# Common Boolean operators #1
# -----------------------------------------------------------
# Assign a Boolean value to a and b
a = True
b = False

# print the result of a and b
print("a and b:", a and b)
# print the result of a or b
print("a or b:", a or b)
# print the result of not a
print("not a:", not a)

# -----------------------------------------------------------
# Common Boolean operators #2
# -----------------------------------------------------------

# Take input for the score from the user
score = int(input("Enter the score: "))

# Compare the score and output the corresponding grade
if score >= 90 and score <= 100:
  print("Grade: A")
elif score >= 80 and score < 90:
  print("Grade: B")
elif score >= 70 and score < 80:
  print("Grade: C")
elif score < 70:
  print("Fail")

# -----------------------------------------------------------
# Common Boolean operators #3
# -----------------------------------------------------------
# Open the file for reading
file = open("scores.txt","r")
# Set flags to false
end_of_file = False
found = False
score = input("Enter a score: ")
# While it's not the end of the file and the score has not been found
while not end_of_file and not found:
  # read the line
  scores = file.readline().strip()
  # if the line equals the score
  if score == str(scores):
    found = True
    print("Score found")
  # if the line is empty
  if scores == "":
    end_of_file = True
    print("Score not found")
file.close()