Operators Precendence

Python has priorities in which order the operations are performed. You must use parentheses to change the order of calculations.

However, if you do not use parentheses, the priorities in the operators are as follows:

The precedence among logical operators:

Let's clarify this with example:


              1234567891011
            
# AND is the first operation, OR is the second
first_result = True or False and False # same as True or (False and False)

# OR is the first operation, AND is the second
second_result = (True or False) and False

third_result = not True or False # same as (not True) or False

print('The first expression is:', first_result)
print('The second expression is:', second_result)
print('The third expression is:', third_result)

In the code above, you can see that the expressions only differ because of the parentheses, leading to completely different outcomes. Let's break it down:

first_result is showing that and has higher precedence than or, resulting in True;
second_result uses parentheses to force True or False to evaluate first, then applies and False, resulting in False;
third_result shows that not has the highest precedence, making the expression equivalent to (not True) or False, resulting in False.

Task

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Create a program that checks whether a given year is a leap year. A leap year is divisible by 4 but not divisible by 100, except if it's also divisible by 400. The program should output either 'Leap year' or 'Not a leap year' accordingly.

The main condition of the leap year is that year must be divided by 4. Use year % 4 == 0;
The second condition is that the year must not be divided by 100. Use year % 100 != 0;
But if the year is divisible by 400 is the leap year. Use year % 400 == 0.

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Section 1. Chapter 6

Operators Precendence

Python has priorities in which order the operations are performed. You must use parentheses to change the order of calculations.

However, if you do not use parentheses, the priorities in the operators are as follows:

The precedence among logical operators:

Let's clarify this with example:


              1234567891011
            
# AND is the first operation, OR is the second
first_result = True or False and False # same as True or (False and False)

# OR is the first operation, AND is the second
second_result = (True or False) and False

third_result = not True or False # same as (not True) or False

print('The first expression is:', first_result)
print('The second expression is:', second_result)
print('The third expression is:', third_result)

In the code above, you can see that the expressions only differ because of the parentheses, leading to completely different outcomes. Let's break it down:

first_result is showing that and has higher precedence than or, resulting in True;
second_result uses parentheses to force True or False to evaluate first, then applies and False, resulting in False;
third_result shows that not has the highest precedence, making the expression equivalent to (not True) or False, resulting in False.

Task

Swipe to show code editor

The main condition of the leap year is that year must be divided by 4. Use year % 4 == 0;
The second condition is that the year must not be divided by 100. Use year % 100 != 0;
But if the year is divisible by 400 is the leap year. Use year % 400 == 0.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 1. Chapter 6

Switch to desktop for real-world practiceContinue from where you are using one of the options below