Conditionals¶

Let us go through conditionals in Python. We typically use “if else” for conditionals. Let us perform a few tasks to understand how conditionals are developed.

Create a variable i with 5. Write a conditional to print whether i is even or odd.

i = 5

# Regular if else
if i % 2 == 0:
    print("even")
else:
    print("odd")

odd

# (cond) ? on_true : on_false

# on_true (cond) else on_false

# Ternary Operator (one liner)
print("even") if i % 2 == 0 else print("odd")

odd

Improvise it to check if i is 0 and print zero

i = int(input("Enter an integer: "))

Enter an integer:  10

if i == 0:
    print(f"i is 0")
elif i % 2 == 0:
    print(f"{i} is even")
else:
    print(f"{i} is odd")

10 is even

Object of type None is special object which represent nothing. At times we need to check against None.

n = None
print('Not None') if n else print(n)

None

i = int(input("Enter an integer: "))

Enter an integer:  10

if i:
    print('Not None') 
else: print(n)

None

i = int(input("Enter an integer: "))

Enter an integer:  9

if not i % 2 == 0: print(f'{i} is odd')

9 is odd

We can also perform boolean operations such as boolean or and boolean and.

Task 1¶

Determine the category of the baby.

Print New Born or Infant till 6 months.
Print Toddler from 7 months to 18 months.
Print Grown up from 19 months to 144 months.
Print Youth from 145 months to 216 months

age = int(input('Enter age in months: '))

Enter age in months:  5

if age <= 6:
    print('New Born or Infant')
elif age > 6 and age <= 18:
    print('Toddler')
elif age > 18 and age <= 144:
    print('Grown up')
elif age > 144 and age <= 216:
    print('Youth')
else:
    print('Adult')

New Born or Infant

Task 2¶

Check if the number is even or divisible by 3.

n = int(input('Enter integer: '))

Enter integer:  6

if n % 2 == 0 or n % 3 == 0:
    print(f'Number {n} is even or divisible by 3')

Number 6 is even or divisible by 3

Task 3¶

Check if the number is even and divisible by 3

n = int(input('Enter integer: '))

Enter integer:  6

if n % 2 == 0 and n % 3 == 0:
    print(f'Number {n} is even and divisible by 3')
elif n % 3 == 0:
    print(f'Number {n} is divisible by 3 but not even')
elif n % 2 == 0:
    print(f'Number {n} is even but not divisible by 3')

Number 6 is even and divisible by 3

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