## Values, Types, Variable Names, and Keywords

Read these examples of using the 'print' and 'type' functions. You can also try to use them in the Repl.it command line.

When more than one operator appears in an expression, the order of evaluation depends on the **rules of precedence**. For mathematical operators, Python follows mathematical convention. The acronym **PEMDAS** is a useful way to remember the rules:

**P**arentheses have the highest precedence and can be used to force an expression to evaluate in the order you want. Since expressions in parentheses are evaluated first,`2 * (3-1)`

is 4, and`(1+1)**(5-2)`

is 8. You can also use parentheses to make an expression easier to read, as in`(minute * 100) / 60`

, even if it doesn't change the result.**E**xponentiation has the next highest precedence, so`2**1+1`

is 3, not 4, and`3*1**3`

is 3, not 27.**M**ultiplication and**D**ivision have the same precedence, which is higher than**A**ddition and**S**ubtraction, which also have the same precedence. So`2*3-1`

is 5, not 4, and`6+4/2`

is 8, not 5.- Operators with the same precedence are evaluated from left to right (except exponentiation). So in the expression
`degrees / 2 * pi`

, the division happens first and the result is multiplied by`pi`

. To divide by 2 π, you can use parentheses or write`degrees / 2 / pi`

.

I don't work very hard to remember rules of precedence for other operators. If I can't tell by looking at the expression, I use parentheses to make it obvious.