Final Exam(sample), Fall, 2014

Transcription

1 Final Exam(sample), Fall, 2014 Date: Dec 4 th, 2014 Time: 1.25 hours (1.00 a.m. 2:15 p.m.) Total: 100 points + 20 bonus Problem 1 T/F 2 Choice 3 Output Points Programming 20 5 Bonus 20 Total /9

2 1. True /False (8 x 2 pts = 16 pts.) 1) Programs no longer require modification after they are written and debugged. [F ] 2) A list must contain at least one item. [F ] 3) The first parameter of a Python method definition is called this. [F ] 4) Unlike string, Python lists are not mutable. [F ] 5) The last character of a string s is at position len(s) -1. [T ] 6) In Python = 36. [T ] 7) Keywords make good variable names. [F ] 8) Formal and actual parameters are matched up by name. [F ] 2. Multiple choice ( 8 x 2 pts = 16 pts.) Please circle the right answer. 1) What Python reserved word starts a class definition? a) def b) class c) object d) init 2) within a method function in a class, the instance variable x could be accessed via which expression? a) x b) self.x c)self[x] d) self.getx() 3) which of the following expressions correctly tests if x is even? a) x % 2 == 0 b) even(x) c) not odd(x) d) x % 2 == x 4) What keyword parameter is used to send a key-function to the sort method? a) reverse b) reversed c) cmp d) key 5) Which of the following is the same as s[0:-1]? a) s[-1] b) s[:] c) s[:len(s)-1] d) s[0:len(s)] 6) Which of the following is not a Python data type? a) int b) float c) rational d) string 7) The value of 4! is a) 9 b) 24 c) 41 d) 120 8) Which of the following is not a legal identifier? a) spam b) spam c) 2spam d) spam4u 2/9

3 3. (total 48 points) What are the outputs of the following codes? 1) String (4 x 3 = 12 points) a) print "Hello world\n\npython" Hello world Python b) a = "Hello " b = "world!" print a+b Hello world! c) a = len("georgia") print (a) 7 d) school = "Georgia State University" print school[3:10] rgia St 2) String methods (4 x 2 = 8 points) a) school = "Georgia State University" a = school.find('a') print (a) 6 3/9

4 b) word = "secret" words = word.split("e") for w in words: print (w) s cr t 3) File (4 x 2 = 8 points) a) File: grade.txt has 4 lines. line 1 line2 line3 line4 i. f = open('grade.txt') print (f.read( )) f.close( ) line1 line2 line3 line4 ii. f = open('grade.txt') print (f.readline( )) f.close( ) line1 4) Loop (4 x 3 = 12 points) 4/9

5 a) for x in [5,6,8, 2,3] : if x < 4: print(x) break 2 b) school = "Georgia State University" strlen = len(school) seq = range(strlen) count = 0 for i in seq: if school[i] == 'a' or school[i] == 'e' or school[i] == 'i' : count = count + 1 elif school[i] == 'o' or school[i] == 'u' : count = count + 1 print count 9 c) x = 0 while x<5: print x x = x ) Data Collections (4 x 2 = points) a) scores = [5, 10, 25, 2] 5/9

6 print scores[3] 2 b) scores = [5, 10, 25, 2] scores.append(15) print scores [5, 10, 25, 2, 15] 4. Programming (10 x 2 = 20 points) 1) Write a program to find all of the largest number in a list. all_largest.py def all_largest(lst): define a list to save all largest number largest = [] find the largest num maxnum = max(lst) for i in lst: if i == maxnum: largest.append(i) return largest def main(): lst = input("please input a list of number>>") to find all of the largest number largests = all_largest(lst) print (" all of the largest number in the input list are: ", largests) main() 2) Write a program to find the frequency of a specific number Require: Prompt user to input a list of number Prompt user to input a number that you want to count its frequency such as, you input a list : [1,2,3,4,2,5,2] and you want to count the frequency of 2, then your program should print the frequency of 2, which is 2. 6/9

7 frequency.py def count(lst,num): define a list to save all largest number count = 0 find the num in the list for i in lst: if i == num: count = count +1 return count def main(): using list to convert the input to list lst = list(input("please input a list of number>> ")) to find all of the largest number num = input("please specify a num>> ") frequency = count(lst,num) print (" The frequency of ", num, "in the list is :", frequency) main() 7/9

8 5. Bonus (20 points) Card Game (20 points) We are writing a new card game that uses only number cards (2, 3, 4, 5, 6, 7, 8, 9, 10). A player will draw 5 cards from a deck and then throw cards out of his hand until the total point of all remaining cards is lower or equal to 15. Complete the program on the next page by repeatedly removing the first card from the list (playerhand) until the total point of all remaining cards is less than or equal to 15. At the end of the program, print out the total point of card in player's hand. Example playerhand Remove cards Remaining cards Total point 1 [8, 2, 4, 5, 6] 8 2 [4, 5, 6] 15 2 [9, 5, 7, 8, 2] [8, 2] 10 3 [6, 2, 5, 3, 4] 6 [2, 5, 3, 4] 14 4 [6, 5, 2, 10, 7] [7] 7 Hint: first, input a list with 5 numbers from (2, 3, 4, 5, 6, 7, 8, 9, 10) second, compute the sum of the list check whether the sum is larger than 15 or not, if larger than 15, you may remove the first element of the list, and repeat the second step at least, you output the left elements of the list and their sum card_game.py def sum_left(lst): sum = 0 calculate the sum of the list 'lst' for i in lst: sum = sum + i return sum def main(): lst = list(eval(input("please input five number>> "))) to find all of the largest number num = input("please specify a num>> ") is the sum of left numbers in the list larger than 15? sum1 = sum_left(lst) while sum1 > 15: del lst[0] lst.pop(0) sum1 = sum_left(lst) 8/9

9 sum1 = sum(lst) print(" The left elements are: ", lst) print(" The sum of left elements is: ", sum1) main() 9/9