if the logical condition is truethen the indented statement gets executed if the logical condition is falsethe indented statement is skipped if statements have the same structure as function definitions or for loops the statement consists of header line that ends with the colon character (:followed by an indented block statements like this are called compound statements because they stretch across more than one line there is no limit on the number of statements that can appear in the bodybut there must be at least one occasionallyit is useful to have body with no statements (usually as place holder for code you haven' written yetin that caseyou can use the pass statementwhich does nothing if pass need to handle negative valuesif you enter an if statement in the python interpreterthe prompt will change from three chevrons to three dots to indicate you are in the middle of block of statementsas shown belowx if print('small'small when using the python interpreteryou must leave blank line at the end of blockotherwise python will return an errorx if print('small'print('done'file ""line print('done'syntaxerrorinvalid syntax blank line at the end of block of statements is not necessary when writing and executing scriptbut it may improve readability of your code alternative execution second form of the if statement is alternative executionin which there are two possibilities and the condition determines which one gets executed the syntax looks like this we will learn about functions in and loops in