13.5. Chapter 13 - Summary¶
Chapter 13 included the following concepts from computing.
Boolean Expression - A Boolean expression is one that is either true or false. This is also called a logical expression.
Condition - A condition is something that is either true or false. This is also called a Boolean expression or a logical expression.
Conditional Execution - Conditional execution means that one or more statements are executed only when a condition (logical expression) is true. This is also called a conditional. The statements that are executed when the condition is true are called the body.
Decision - A decision is a choice between at least two choices.
Input - The
input
function returns a value that the user enters.Logical Expression - A logical expression is one that is either true or false, like
x == 3
. This is also called a Boolean expression.
13.5.1. Summary of Python Keywords and Functions¶
And - The keyword
and
is used to join two logical expressions and then both of the logical expressions must be true for the joined expression to be true.Else - The keyword
else
is used to execute one or more statements in a block following theelse
when the condition in theif
part of the statement is false. Anelse
must always have anif
statement before it.Elif - The keyword
elif
is used when you want to have a conditional with 3 or more possibile options. Add as manyelif
statements as you need after anif
and before aelse
.If - The Python keyword
if
is used to start a condition. It is followed by a Boolean expression and then has one or more statements in the body of the loop that are executed only if the Boolean expression is true.Not - The keyword
not
is used to negate a logical expression. If the original expression is true the negated expression is false and if the original expression is false the negated expression is true.Str - The function
str
turns a number into a string so that it can be appended to a string.
Note
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