Question

example of Boolean literal​

Answer 1

Answer:

the picturevis blur

Explanation:

re upload it.

Answer 2

Explanation:

Conditionals¶

Programs get really interesting when we can test conditions and change the program behaviour depending on the outcome of the tests. That’s what this chapter is about.

5.1. Boolean values and expressions

A Boolean value is either true or false. It is named after the British mathematician, George Boole, who first formulated Boolean algebra — some rules for reasoning about and combining these values. This is the basis of all modern computer logic.

In Python, the two Boolean values are True and False (the capitalization must be exactly as shown), and the Python type is bool.

>>> type(True)

<class 'bool'>

>>> type(true)

Traceback (most recent call last):

File "<interactive input>", line 1, in <module>

NameError: name 'true' is not defined

A Boolean expression is an expression that evaluates to produce a result which is a Boolean value. For example, the operator == tests if two values are equal. It produces (or yields) a Boolean value:

>>> 5 == (3 + 2) # Is five equal 5 to the result of 3 + 2?

True

>>> 5 == 6

False

>>> j = "hel"

>>> j + "lo" == "hello"

True

In the first statement, the two operands evaluate to equal values, so the expression evaluates to True; in the second statement, 5 is not equal to 6, so we get False.

The == operator is one of six common comparison operators which all produce a bool result; here are all six:

x == y # Produce True if ... 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

Although these operations are probably familiar, the Python symbols are different from the mathematical symbols. A common error is to use a single equal sign (=) instead of a double equal sign (==). Remember that = is an assignment operator and == is a comparison operator. Also, there is no such thing as =< or =>.

Like any other types we’ve seen so far, Boolean values can be assigned to variables, printed, etc.

>>> age = 18

>>> old_enough_to_get_driving_licence = age >= 17

>>> print(old_enough_to_get_driving_licence)

True

>>> type(old_enough_to_get_driving_licence)

<class 'bool'>

5.2. Logical operators

There are three logical operators, and, or, and not, that allow us to build more complex Boolean expressions from simpler Boolean expressions. The semantics (meaning) of these operators is similar to their meaning in English. For example, x > 0 and x < 10 produces True only if x is greater than 0 and at the same time, x is less than 10.

n % 2 == 0 or n % 3 == 0 is True if either of the conditions is True, that is, if the number n is divisible by 2 or it is divisible by 3. (What do you think happens if n is divisible by both 2 and by 3 at the same time? Will the expression yield True or False? Try it in your Python interpreter.)

Finally, the not operator negates a Boolean value, so not (x > y) is True if (x > y) is False, that is, if x is less than or equal to y.

The expression on the left of the or operator is evaluated first: if the result is True, Python does not (and need not) evaluate the expression on the right — this is called short-circuit evaluation. Similarly, for the and operator, if the expression on the left yields False, Python does not evaluate the expression on the rights