parameterless accessor call (invoke) mutator normal parameter object parameters self parameter string methods activate clicked deactivate dictionary list model-view module file module hierarchy chartsee structure chart molecular weight monte carlo month abbreviation problem description program month py month py move movetower mpg msdie mutable mutator nameerror names nesting newline character (\ ) with readline newton' method none numbers text py numerology object aliasing application as as black box as parameter attributes definition of state object-oriented object-oriented design (ood) objects built-in none graphicssee graphics libraryobjects othersee classes objrball py old macdonald one-way decision open operator boolean as control structure definition of precedence relational short-circuit operators boolean del list mathematical python numeric operators relational or operational definition ord output labeling output statements oval override overtime palindrome parameter actual as function input formal matching by order multiple objects as removing code duplication scope issues self pi math library