Python Programming with the Java™ Class Libraries: A Tutorial for Building Web and Enterprise Applications with Jython

Expressions

Expressions are also instructions to Python to perform a task. That task is to return a value, such as the result of a mathematical operation or the truth or falsity of a statement. Expressions can be assigned variables. Also, many of them use operators, which can be words like and, or, and not, or symbols such as + (plus), - (minus), * (multiplication), and = (equals). We'll cover operators in detail in Chapter 3. For now, just remember that expressions return a value and usually use operators.

For Novices: Expressions in Spreadsheets If you've ever used spreadsheets, you've used expressions and operators. An expression is equivalent to a spreadsheet formula. Let's say that, in cell D1 of a spreadsheet, you have the formula =(A1*B1)/C1 ...