Selection

Question 1

Boolean values

Answer 1

True and False

A Boolean expression is an expression that evaluates to a Boolean value

Question 2

Comparision operator

Answer 2

x == y # x is equal to y 
x != y # x is not equal to y 
x > y # x is greater than y 
x < y # x is less than y 
x >= y # x is greater than or equal to y 
x <= y # x is less than or equal to y

Question 3

Logical operators

Answer 3

And Or Not
example:
x = 5
print x > 0 and x <10

n = 25
print n % 2 == 0 or n % 3 == 0

Question 4

Precedences of operator

Answer 4

• Python will always evaluate the arithmetic operators first (exponentiation is
highest, then multiplication/division, then addition/subtraction)
• Next comes the comparison operators (sometime called relational operators)
• Finally, the logical operators are done last

Question 5

If statement

Answer 5

if boolean expression:
statements_1 # executed if condition evaluates to True
else:
statements_2 # executed if condition evaluates to False

Question 6

Unary selection

Answer 6

x = int(raw_input(“Please enter an integer: “))

if x < 0:
print “The negative number “, x, “ is not valid here.”
print “This is always printed”

Question 7

Nested conditionals

Answer 7

if x < y: 
 print "x is less than y” 
else: 
 if x > y: 
 print "x is greater than y” 
 else: 
 print "x and y must be equal”

Question 8

Chained conditionals

Answer 8

if x < y: 
 print "x is less than y” 
elif x > y: 
 print "x is greater than y” 
else: 
 print "x and y must be equal”

Question 9

Boolean functions

Answer 9

def is_divisible(x, y): 
 if x % y == 0: 
 result = True 
 else: 
 result = False 

return result

print is_divisible(10, 5)