Chapter 1-5 Exercises

Question 1

Write a program that uses input to prompt a user for their name and then welcomes them.

Answer 1

name = input(“Enter your name:\n”)

print(“Hello”, name)

Question 2

Write a program to prompt the user for hours and rate per hour to compute gross pay.

Answer 2

hours = int(input(“Enter hours: “))
rate = float(input(“Enter rate: “))
pay = hours * rate
print(“Pay: “, pay)

Question 3

Write a program which prompts the user for a Celsius temperature, convert the temperature to Fahrenheit, and print out the converted temperature.

Answer 3

cels = float(input(“Enter the temperature in Celsius: “))
fahr = cels * 1.8 + 32
print(“Temperature in Fahrenheit: “, fahr)

Question 4

Rewrite your pay computation to give the employee 1.5 times the hourly rate for hours worked above 40 hours.
Enter Hours: 45
Enter Rate: 10
Pay: 475.0

Answer 4

hours = int(input("Enter hours: ")) 
rate = float(input("Enter rate: ")) 
if hours > 40: pay = (hours - 40)*rate*1.5 + 40 * rate 
else: pay = hours * rate 
print("Pay: ", pay)

Question 5

Rewrite your pay program using try and except so that your program handles non-numeric input gracefully by printing a message and exiting the program. The following shows two executions of the program:

Enter Hours: 20
Enter Rate: nine
Error, please enter numeric input

Enter Hours: forty
Error, please enter numeric input

Answer 5

try: 
  hours = int(input("Enter hours: ")) 
  rate = float(input("Enter rate: "))
except: 
  print("Error, please enter numeric input!") 
  quit() 
if hours > 40: 
  pay = (hours - 40)*rate*1.5 + 40 * rate 
else: 
  pay = hours * rate 
print("Pay: ", pay)

Question 6

Write a program to prompt for a score between 0.0 and 1.0. If the score is out of range, print an error message. If the score is between 0.0 and 1.0, print a grade using the following table:

Score Grade 
>= 0.9 A 
>= 0.8 B 
>= 0.7 C 
>= 0.6 D  
< 0.6 F

Enter score: 
0.95 A 
Enter score: perfect Bad score 
Enter score: 10.0 Bad score 
Enter score: 0.75 C 
Enter score: 0.5 F

Answer 6

try: 
  grade = float(input("Enter score: "))
except: 
  print("Bad score") 
  quit() 

if grade < 0 or grade > 1.0: 
  print("Score is out of range!")
elif grade >= 0.9: 
  print("A")
elif grade >= 0.8: 
  print("B")
elif grade >= 0.7: 
  print("C")
elif grade >= 0.6: 
  print("D")
else: 
  print("F")

Question 7

Exercise 1: Write a program which repeatedly reads numbers until the user enters “done”. Once “done” is entered, print out the total, count, and average of the numbers. If the user enters anything other than a number, detect their mismistake using try and except and print an error message and skip to the next number.

Enter a number: 4 
Enter a number: 5 
Enter a number: bad data 
  Invalid input 
Enter a number: 7 
Enter a number: done 
16 3 5.333333333333333

Answer 7

count = 0
total = 0 

while True: 
  str_val = input("Enter a number:") 
  if str_val == 'done': 
    break 
  try: 
    val = float(str_val) 
  except: 
    print("Invalid input") 
    continue 
  total = total + val 
  count = count + 1 
print(total, count, total/count)

Question 8

Write another program that prompts for a list of numbers as above and at the end prints out both the maximum and minimum of the numbers instead of the average.

Enter a number: 4 
Enter a number: 5 
Enter a number: bad data 
  Invalid input 
Enter a number: 7 
Enter a number: done

Answer 8

count = 0

while True: 
  str_val = input("Enter a number:") 
  if str_val == 'done': 
    break 
  try: 
    val = float(str_val) 
  except: 
    print("Invalid input") 
    continue 
  if count == 0: 
    min_val = val 
    max_val = val 
  elif val < min_val: 
    min_val = val 
  elif val > max_val: 
    max_val = val 
  count = count + 1 

print(min_val, max_val)

Question 9

Exercise 6: Rewrite your pay computation with time-and-a-half for overtime and create a function called computepay which takes two parameters (hours and rate).

Enter Hours: 45
Enter Rate: 10
Pay: 475.0

Answer 9

def computepay(hours, rate): 
  if hours > 40: 
    pay = (hours - 40)*rate*1.5 + 40 * rate 
  else: 
    pay = hours * rate 
  return pay 

hours = int(input("Enter hours: "))
rate = float(input("Enter rate: "))
pay = computepay(hours, rate)

print(“Pay: “, pay)

Question 10

Exercise 7: Rewrite the grade program from the previous chapter using a function called computegrade that takes a score as its parameter and returns a grade as a string.

Score Grade 
>= 0.9 A 
>= 0.8 B 
>= 0.7 C 
>= 0.6 D  
< 0.6 F 

Enter score: 0.95 A 
Enter score: perfect Bad score 
Enter score: 10.0 Bad score 
Enter score: 0.75 C 
Enter score: 0.5 F 

Run the program repeatedly to test the various different values for input.

Answer 10

def computegrade(grade): 
  if grade < 0 or grade > 1.0: 
    return "Score is out of range!" 
  elif grade >= 0.9: 
    return "A" 
  elif grade >= 0.8: 
    return "B" 
  elif grade >= 0.7: 
    return "C" 
  elif grade >= 0.6: 
    return "D" 
  else: 
    return "F" 

try: 
  grade = float(input("Enter score: "))
except: 
  print("Bad score") 
  quit() 

print(computegrade(grade))