CSCI/CMPE 4341 Topic: Programming in Python Chapter 5: Functions – Exercises Xiang Lian The University of Texas – Pan American Edinburg, TX

Objectives In this chapter, you will do some exercises about: – Functions in Python 2

Multiple Choices Constructing a large program from smaller components is called ______. – A. object-oriented programming B. algorithm design – C. divide and conquer D. writing pseudo-code "Pre-packaged" functions or classes are available in Python ______. – A. functions B. classes C. modules D. packages The ______ module functions allow programmers to perform common mathematical calculations. – A. random B. built-ins C. math D. iostream The indented statements that follow a ______ statement form a function body. – A. void B. int C. def D. None of the above The ______ module introduces the element of chance into Python programs. – A. rand B. math C. random D. cmath 3

Multiple Choices (cont'd) A function ______ produces pseudorandom numbers. – A. Math.random() B. math.randomNum() – C. random.Randomrange() D. random.randrange() During the code execution, three namespaces below can be accessed except for: – A. local namespace B. global namespace C. nested namespace – D. built-in namespace A method that calls itself either directly or indirectly is a(n) __________method. – A. static B. dynamic C. public D. recursive A recursive function converges on the _____. – A. initial case B. base case C. procedure that calls itself D. procedure that calls other functions 4

Multiple Choices (cont'd) Which of the following statements generates a random number between 1 and 4 (inclusive)? – A. random.randrange(0, 4) – B. random.rand(1, 5) – C. random.randrange(1, 5) – D. random.randrange(0, 4)+1 5

True/False Statements All variables declared in a function are global to the program containing the function. An import statement must be included for every module function used in a program. Function fmod returns the floating-point remainder of its two arguments. The keyword return displays the result of a function. The keyword return is required in the Python function. 6

True/False Statements (cont'd) Function call random.randrange(1, 7) produces a random integer in the range 1 to 7, inclusive. An identifier's scope is the portion of the program in which the identifier has meaning. Every call to a recursive function is a recursive call. Omitting the base case in a recursive function can lead to "infinite" recursion. A recursive function may call itself indirectly. 7

What Does the Code Do? math.floor(4.5) math.ceil(4.0) math.ceil(4.1) 8

Debug Errors Def square(a) Return a*a void G(a) Return x*G(a-1) 9

Write a Program Write a method in Python to return the larger value of two decimal numbers. Write another program in Python to return the largest value among 3 decimal numbers, by invoking the method above. 10

Write a Program (cont'd) Write a recursive method in Python to compute the Fibonacci number: – 1, 1, 2, 3, 5, 8, 13, 21, 34,.... – Given the first two numbers of the sequence (say, a 1 and a 2 ) – n-th number a n, n >= 3, of this sequence is given by: a n = a n-1 + a n-2 11