Ch. 2

Question 1

list and describe the six steps in software development process

Answer 1

plan, design, develop, test, deploy, maintain

Question 2

explain the relationship among the concepts definite loop, for loop, and counted loop

Answer 2

def loop- Used to repeat a block of code a number of times. The number of iterations is known in advance.
for loop- continues to execute as long as the condition is true.
counted loop- relies on a counter variable

Question 3

show the output from the following fragments:
for i in range (5):
print(i*i)

Answer 3

1. i range is 0,1,2,3,4
2. go through for loop using i
   a. 0 0
   b. 11
   c. 22
   d. 33
   e. 4*4
3. output:
   0
   1
   4
   9
   16

Question 4

for d in [3,1,4,1,5]:
print(d, end=” “)

Answer 4

1. [ ] means list
2. 3 gets printed
3. bc end= “ “, the following numbers will get printed next to each other
4. output: 3 1 4 1 5

Question 5

for i in range(4):
print(“Hello”)

Answer 5

1. range is 0,1,2,3
2. Hello is printed 4 times
3. output:
   Hello
   Hello
   Hello
   Hello

Question 6

for i in range(5):
print(i, 2**i)

Answer 6

1. ** means to the power of
2. range is 0,1,2,3,4
3. outcome:
   0 1
   1 2
   2 4
   3 8
   4 16

Question 7

why is it a good idea to first write out pseudocode rather than to python code first

Answer 7

helps to plan and organize

Question 8

what does sep parameter do

Answer 8

print(“apple”, “banana”, sep=’-‘)
Prints “apple-banana”

Question 9

what will happen:

print(“start”)
for i in range(0):
print(“Hello”)
print(“end”)

Answer 9

start
end
“hello” doesn’t print because a number between 0 and 0 doesn’t exist

Question 10

write a program that converts fahrenheit to celsius

Answer 10

celsius = eval(input(“enter celsius”))
fahrenheit = 9/5 * celsius + 32
print(“celsius in fahrenheit is”, fahrenheit)

Question 11

write a program that converts distances measured in kilometers to miles. one kilometer is approx .62 miles

Answer 11

kilometers = eval(input(“enter kilometers “))
miles = kilometers * .62
print(kilometers, “kilos in miles is”, miles)

Question 12

write an interactive python calculator program

Answer 12

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