makes this "block-structured code(he sayssarcasticallynoin any block-structured languagepython or otherwiseif nested blocks are not indented consistentlythey become very difficult for the reader to interpretchangeor reusebecause the code no longer visually reflects its logical meaning readability mattersand indentation is major component of readability here is another example that may have burned you in the past if you've done much programming in -like language consider the following statement in cif (xif (ystatement else statement which if does the else here go withsurprisinglythe else is paired with the nested if statement (if ( )in ceven though it looks visually as though it is associated with the outer if (xthis is classic pitfall in the languageand it can lead to the reader completely misinterpreting the code and changing it incorrectly in ways that might not be uncovered until the mars rover crashes into giant rockthis cannot happen in python--because indentation is significantthe way the code looks is the way it will work consider an equivalent python statementif xif ystatement elsestatement in this examplethe if that the else lines up with vertically is the one it is associated with logically (the outer if xin sensepython is wysiwyg language--what you see is what you get--because the way code looks is the way it runsregardless of who coded it if this still isn' enough to underscore the benefits of python' syntaxhere' another anecdote early in my careeri worked at successful company that developed systems software in the languagewhere consistent indentation is not required even sowhen we checked our code into source control at the end of the daythis company ran an automated script that analyzed the indentation used in the code if the script noticed that we' indented our code inconsistentlywe received an automated email about it the next morning--and so did our managersthe point is that even when language doesn' require itgood programmers know that consistent use of indentation has huge impact on code readability and quality the fact that python promotes this to the level of syntax is seen by most as feature of the language also keep in mind that nearly every programmer-friendly text editor has built-in support for python' syntax model in the idle python guifor examplelines of code introducing python statements