11.1.1.7 apply logic operations to Boolean variables;
11.1.1.9 implement the branching algorithm according to the flowchart;

Python. If-Else statements

Selection - is a programmatic construct in which a piece of code is run only when a condition is met.

if <bool expression>:     statement1     statement2     …	if <bool expression>:     statement1     statement2     … else:     statement1     statement2     …

Comparison operations

Example

print('Enter password:')
password = input()
if password == 'qwerty':
    print('Access is opened!')
else:
    print('Error.')

Task1

Code:

x = float(input())
if x > 0:    
    Y = 2 * x
else:    
    Y = x ** 2
print(Y)

One line if statement in Python (ternary conditional operator)

x = int(input("How old are you? "))
print("Kid") if x < 18 else print("Adult")  # ternary conditional operator

x = int(input("How old are you? "))
print("Kid" if x < 18 else "Adult")  # ternary conditional operator

if-elif-else statement

if <bool expression1>:
    statement1
    …
elif <bool expression2>: 
    statement1
    …
elif <bool expression3>: 
    statement1
    statement2
    …
else:
    statement1
    statement2
 

Task 2

Code:

x = float(input())
if x > 5:
    Y = x – 1
elif x < -5:
    Y = x ** 2
else:
    Y = x ** 2 + x
print(Y)

Questions:

Exercises:

Tasks:

Tasks on Stepik.org course "Python Programming for NIS"