Python Condition Execution

 

chapter-3

Condition execution

python if...else

syntax

if test expression:

   statement(s)

example 1

a= int(input("enter first numbers .."))

b=int(input("enter second number.."))

if a>b:

   print("a is greatest")

if b>a:

   print("b is greatest")

output

enter  first number...2

enter second numbers...4

b is greatest

enter  first  number ...23

enter second number...12

a is greatest

 

Example 2

Given Number Is Positive  Negative  Or Zero

num =int(input("enter a number.."))

if num>0:

     print(num, "is a positive number.")

if num<0:

    print(num, "is a negative number..")

if num==0:

    print("the given number is zero")

 

output

enter a number..4

4, 'is a positive  number.'

enter a number..-6

-6, 'is a negative number..'

enter a number..0

the given number is zero

 

IF...ELSE statement

syntax

if test expression

   body of if stament(s)

else:

   body of else statemet(s)

example:-

num=int(input("enter a number .."))

if num %3==0:

    print(num, "is divisible  by 3.")

else:

   print(num, "is not divisible  by  3")

 

output

enter a number ..5

5, 'is not divisible  by 3'

 enter a number ...12

12, 'is divisible  by 3.'

program 2

num ==int(input("enter a number.."))

if num >=0:

    print("positive number")

else:

   print("negative  number")

 

output

enter a number ...34

positive number

enter  a  number..-56

negative number

python IF...ELIF...ELSE

syntax

if test expression:

     body of if statement(s)

elif test expresion:

     body of elif statement(s)

else:

     body of else statement(s)

program:-

a=int(input("enter  first number.."))

b=int(input("enter second number.."))

c=int(input("enter 3rd number,,,"))

if a>b and a>c:

    print("greatest is a ")

elif  b>c:

   print("greatest is b")

else:

  print("greatest is c")

 

output

enter  first number..1

enter second number....3

enter 3rd number..2

greatest is b

 

enter  first number..1

enter second number....2

enter 3rd number..3

greatest is c

 

enter  first number..4

enter second number....2

enter 3rd number..3

greatest is a

 

Nested if statements

program example

num=float(input("enter a number: "))

if num >=0:

   if num ==0:

       print("zero")

   else:

      print("positive number")

else:

   print("negative number")

output

enter a number:5

positive number

enter a number: -1

negative number

enter a number: 0

zero

Iteration

for loop structure

syntax

for val in sequences:

     [body of for loop statement(s)]

example program

for i in "HAI":

    print(i)

output

H
A
I

 

The range () function

example

for i in range(5,50,5):

   print(i)

output

5

10

15

20

25

30

35

40

45

For loop with else

example

digits=[1,2,3,4,5,6,7,8,9,10]

for i digits:

    print(i)

else:

print("no items left.")

output

1

2

3

4

5

6

7

8

9

10

no items left

While loop structure

syntax

while <test_expression>:

     body of while loop

example:

n=int(input("enter n:"))

sum=0

i=1

while i<=n:

  sum= sum +i

  i = i+1

  print("the sum is",sum)

output

enter n: 10

the sum is 55

While loop with else

program

i=1

while i<=3:

     print("\n inside loop")

     i= i+1

else:

print("\n finally print while condition is flase")

output

inside loop

inside loop

inside loop

finally print while condition is false

Break and continue

example

for val in "string":

    if val == "i":

        break

    print(val)

print("The end")

output

S

T

R

the end

python continue statements

for val in "string":

   if val == "i":

        continue

    print(val)

print("the end")

 

output

s

t

r

n

g

the end

                                      Pass

 

sequence ={'p','a','s','s'}

for val in sequence:

    pass

print(val)

 

 

output

>>>

 RESTART: C:/Users/SERVER/AppData/Local/Programs/Python/Python37-32/jhgkjds.py

p

>>>

 RESTART: C:/Users/SERVER/AppData/Local/Programs/Python/Python37-32/jhgkjds.py

s

>>>

 RESTART: C:/Users/SERVER/AppData/Local/Programs/Python/Python37-32/jhgkjds.py

a

>>>

 RESTART: C:/Users/SERVER/AppData/Local/Programs/Python/Python37-32/jhgkjds.py

p

>>>