Jared Nielsen <nielsen.ja...@gmail.com> writes: > Could someone explain the difference between expressions and > statements?
For general programming terminology, the Wikipedia articles tend to be good. <URL:https://en.wikipedia.org/wiki/Expression_%28computer_science%29> <URL:https://en.wikipedia.org/wiki/Statement_%28computer_science%29> Roughly: * An expression evaluates to some single value. * A statement does some action. > I know that expressions are statements that produce a value. Expressions are not statements. A statement *may* be an expression. Statements in Python can consist of an expression, or can consist of other things. > I'm unclear on functions and especially strings. You're looking for a strict dichotomy which doesn't exist, and I think that's confusing you. > Are any of the following expressions? They can all be statements. > print(42) > print("spam") These are function calls. A function call evaluates to a value, so is always an expression. > spam = 42 Assignment is only a statement in Python. The statement is an instruction to perform the assignment. The left side is an expression evaluating to a reference; the right side is an expression evaluating to a value. > Is a variable assignment considered a value? In Python, assignment (try not to think in terms of “variable”; assignment is the act of binding a reference to a value) is always a statement. In other languages, assignment can return a value and is therefore an expression. That is not the case in Python. > Is the first example producing a value or simply displaying an > integer? > Does a string count as a value? Yes to all these. Learn more about statements – especially the fact that statements consist sometimes of expressions alone, sometimes of other things including expressions – at the Python Language Reference <URL:https://docs.python.org/3/reference/expressions.html> <URL:https://docs.python.org/3/reference/simple_stmts.html>. -- \ “If nature has made any one thing less susceptible than all | `\ others of exclusive property, it is the action of the thinking | _o__) power called an idea” —Thomas Jefferson | Ben Finney _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
