Teach Your Kids To Code: A Parent-friendly Guide to Python Programming

82 Chapter 5

they equal? Each comparison you make using a comparison opera-

tor is a condition that will evaluate to True or False. One real-world

example of a comparison is when you enter a passcode to access a

building. The Boolean expression takes the passcode you entered

and compares it to the correct passcode; if the input matches (is

equal to) the correct passcode, the expression evaluates to True,

and the door opens.

The comparison operators are shown in Table 5-1.

Table 5-1: Python Comparison Operators

Math

symbol

Python

operator

Meaning Example Result

< < Less than 1 < 2 True

> > Greater than 1 > 2 False

≤ <= Less than or equal to 1 <= 2 True

≥ >= Greater than or equal to 1 >= 2 False

= == Equal to 1 == 2 False

≠ != Not equal to 1 != 2 True

As we saw with math operators in Chapter 3, some of the oper-

ators in Python are different from math symbols to make them

easier to type on a standard keyboard. Less than and greater than

use the symbols we’re used to, < and >.

For less than or equal to, Python uses the less than sign and

equal sign together, <=, with no space in between. The same goes for

greater than or equal to, >=. Remember not to put a space between

the two signs, as that will cause an error in your program.

The operator to see if two values are

equal is the double equal sign, ==, because

the single equal sign is already used as the

assignment operator. The expression x = 5

assigns the value 5 to the variable x, but

x == 5 tests to see if x is equal to 5. It’s help-

ful to read the double equal sign out loud as

“is equal to” so you can avoid the common

mistake of writing the incorrect statement

if x = 5 instead of the correct if x == 5

(“if x is equal to five”) in your programs.