functions the max function tells us the "largest characterin the string (which turns out to be the letter " "and the min function shows us the smallest character (which turns out to be spaceanother very common built-in function is the len function which tells us how many items are in its argument if the argument to len is stringit returns the number of characters in the string len('hello world' these functions are not limited to looking at strings they can operate on any set of valuesas we will see in later you should treat the names of built-in functions as reserved words ( avoid using "maxas variable name type conversion functions python also provides built-in functions that convert values from one type to another the int function takes any value and converts it to an integerif it canor complains otherwiseint(' ' int('hello'valueerrorinvalid literal for int(with base 'helloint can convert floating-point values to integersbut it doesn' round offit chops off the fraction partint( int(- - float converts integers and strings to floating-point numbersfloat( float(' ' finallystr converts its argument to stringstr( ' str( '