Common Boolean Operators (OCR GCSE Computer Science): Revision Note

Python code

# -----------------------------------------------------------
# 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()