traceback (most recent call last)file ""line in zerodivisionerrordivision by zero in the first logical expressionx > is false so the evaluation stops at the and in the second logical expressionx > is true but ! is false so we never reach ( /yin the third logical expressionthe ! is after the ( /ycalculation so the expression fails with an error in the second expressionwe say that ! acts as guard to insure that we only execute ( /yif is non-zero debugging the traceback python displays when an error occurs contains lot of informationbut it can be overwhelming the most useful parts are usuallywhat kind of error it wasand where it occurred syntax errors are usually easy to findbut there are few gotchas whitespace errors can be tricky because spaces and tabs are invisible and we are used to ignoring them file ""line indentationerrorunexpected indent in this examplethe problem is that the second line is indented by one space but the error message points to ywhich is misleading in generalerror messages indicate where the problem was discoveredbut the actual error might be earlier in the codesometimes on previous line in generalerror messages tell you where the problem was discoveredbut that is often not where it was caused glossary body the sequence of statements within compound statement boolean expression an expression whose value is either true or false