a b c d e. none of the above

Transcription

1 Multiple choice questions 1-10 are worth 4 points each Question 1 var = 0 num = 1 for i in range(3): if i%2 == 0: num *= -1 var += num print(var, end = ' ') a b c d Question 2 scary = 'boo! boo!' place = 0 while place <= len(scary): current = scary[place] print(current, end='') place += scary.count(current) a. obo b. boo c. oo! d. IndexError: string index out of range Question 3 eap = 'rapping, rapping' print(eap[:4] + eap[-4:]) a. rapping b. rappping c. SyntaxError: negative slice index d. TypeError: can't add slices Question 4 seasonal = 'boo' out = '' idx = 0 while True: letter = seasonal[idx] lettercount = seasonal.count(letter) out += letter if seasonal[idx] > seasonal[idx+1]: idx += lettercount elif seasonal[idx] < seasonal[idx+1]: idx -= lettercount break print(out) a. IndexError: string index out of range b. an infinite loop with no output c. oo d. boo

2 Question 5 favs = ['Leia', 'R2-D2', 'Solo', 'Chewbacca'] vowels = 'aeiou' for vowel in vowels: for fav in favs: if vowel in fav: continue print(fav[0], end='') break a. no output b. LRSC c. SSSLL d. RRRLL Question 6 pairs = {'':'empty', 2:'prime', 1:['polio', 'smallpox']} print(pairs[1][1]) a. TypeError: unhashable type: '' b. r c. smallpox d. {2:'r'} Question 7 def dicttest(atype, adict): if atype in adict: return atype for v in adict.values(): if atype in v: return v types = {string:'string', num:0, tuple:('a','ok')} print(dicttest('string', types)) a. 'string' b. string c. atype d. NameError: name 'string' is not defined Question 8 boolexprs = [True and False, not True, True or False, True and not False] tcount = 0 for expr in boolexprs: if expr == True: tcount = 2*tCount + 1 break print(tcount) a. SyntaxError: and not b. 1 c. 2 d. 3

3 Question 9 def contains(txt, letters): rtn = [] alist = txt.split() for w in alist: if w in letters: rtn.append(w) return rtn burns = "a man's a man for a' that" print(contains(burns, 'abc')) a. [] b. ['a', 'a'] c. ['a', 'a', "a'"] d. ['a', "man's", 'a', 'man', "a'", 'that'] Question 10 def filecount(filename, s): inf = open(filename) count = 0 content = inf.read() for thing in content: if s in thing: count += 1 inf.close() return count w = open('seuss.txt', 'w') w.write('you are on your own' + '\n') w.write('and you know what you know' + '\n') w.close() print(filecount('seuss.txt', 'you')) a. 2 b. 3 c. 4 d. FileNotFoundError

4 Programming questions are worth 20 points each Question 11a (10 points) Write a function named cup that uses a turtle parameter t to draw a cup consisting of three sides of a square. Your function should not change the position or orientation of t before drawing the first side of the cup. The turtle t that is passed to cup may initially be either up or down and may be at any location on the screen and in any orientation. After drawing a side, the turtle t should turn left. When the function cup returns, t should be in the initial position and orientation. For full credit, the repeated operations should be performed in a loop. The function cup takes two parameters t, a turtle that is used for drawing sidelength, the length of a side of the cup The figure at the right shows sample graphical output of cup. Question 11b (10 points) Write a function named cups that calls the function cup repeatedly to draw a set of measuring cups of increasing size. The function cups takes four parameters: t, a turtle used for drawing initial, the length of a side of the first cup incr, the increase in side length of each successive cup reps, the number of cups to draw For example, the graphical output of the code below should look like the illustration at the right: import turtle s = turtle.screen() t = turtle.turtle() cups(t, 50, 30, 4)

5 Question 12 (20 points) Write a function named uniquewords that counts how many different words there are in each line of an input file and writes that count to a corresponding line of an output file. The input file already exists when uniquewords is called. uniquewords creates the output file. Input. The function uniquewords takes two parameters: infile, a string that is the name of a text file that is to be read. The file that infile refers to contains only lower case letters and white space (no punctuation marks or other special characters). outfile, a string that is the name of the file to which uniquewords writes its output. The input file is in the current working directory. uniquewords should create the output file in that directory. Output. For each line of infile, uniquewords should write a corresponding line to outfile containing a single integer: the number of unique words on the line. If the content of the file turn.txt is below, a time to build up a time to break down a time to dance a time to mourn a time to cast away stones a time to gather stones together the function call uniquewords('turn.txt', 'turnout.txt') should create a file named turnout.txt with this content: 7 5 8

6 Question 13 (20 points) Write a function named importantwords that analyzes a text string for words that meet a length threshold. Any word shorter than this threshold is considered unimportant and is ignored. The function importantwords takes two parameters: a string s that contains only lower case letters and white space (no punctuation marks or other special characters). an int threshold that is the minimum length of a word that is considered important Output. Return a dictionary in which each key k is a word in s that is at least threshold characters long. The value corresponding to k is the number of occurrences of k in s. For example, if importantwords is called by these lines: lyric = '''a time to build up a time to break down a time to dance a time to mourn''' print(importantwords(lyric, 4)) then the following would be correct output. {'mourn': 1, 'build': 1, 'down': 1, 'dance': 1, 'time': 4, 'break': 1}