During this activity, students should be able to:
This activity helps students develop the following skills, values and attitudes: proficiency in English, ability to analyze and synthesize, capacity to identify and solve problems, and efficient use of computer systems.
Individually or in pairs, solve the following set of problems using Python 3.4. Run and test each of your programs to make sure they work as expected.
Each source file must include at the top the authors’ personal information (student ID and name) within comments. For example:
# Authors: # A01166611 Pepper Pots # A01160611 Anthony Stark # # Description of problem being solved. # # April 8, 2015. . . (The rest of the program goes here) .
Write a program called positives.py. Define in this program a function called positives(x) that takes a list of numbers x as its argument, and returns a new list that only contains the positive numbers of x.
Test your program with the following main() function:
def main(): print(positives([-21, -31])) print(positives([-48, -2, 0, -47, 45])) print(positives([-9, -38, 49, -49, 32, 6, 4, 26, -8, 45])) print(positives([-27, 48, 13, 5, 27, 5, -48, -42, -35, 49, -41, -24, 11, 29, 33, -8, 45, -44, 12, 46])) print(positives([-2, 0, 27, 47, -13, -23, 8, -28, 23, 7, -29, -24, -30, -6, -21, -17, -35, -8, -30, -7, -48, -18, -2, 1, -1, 18, 35, -32, -42, -5, 46, 8, 0, -31, -23, -47, -4, 37, -5, -45, -17, -5, -29, -35, -2, 40, 9, 25, -11, -32]))
The expected program output should be:
[] [0, 45] [49, 32, 6, 4, 26, 45] [48, 13, 5, 27, 5, 49, 11, 29, 33, 45, 12, 46] [0, 27, 47, 8, 23, 7, 1, 18, 35, 46, 8, 0, 37, 40, 9, 25]
Write a program called dotproduct.py. Define in this program a function called dotproduct(a, b) that takes two arguments: the lists a and b. It returns the result of performing the dot product of a times b. The dot product is an algebraic operation that takes two equal-length sequences of numbers and returns a single number obtained by multiplying corresponding entries and then summing those products:
Test your program with the following main() function:
def main(): print(dotproduct([], [])) print(dotproduct([1, 2, 3], [4, 5, 6])) print(dotproduct([1.3, 3.4, 5.7, 9.5, 10.4], [-4.5, 3.0, 1.5, 0.9, 0.0])) print(dotproduct([92, -39, 82, 16, -64, -1, -16, -45, -7, 39, 45, 0, 34, -3, -51, 71, 23, -8, 41, -40], [-50, -81, 94, -84, 47, 86, 52, 19, -57, 36, -20, 11, -42, 48, 14, 13, 9, -67, 92, 96]))
The expected program output should be:
0 32 21.45 357
Write a program called replicate.py. Define in this program a function called replicate(n, x) that takes two arguments: a list x and an integer number n, where n ≥ 0. It returns a new list that replicates n times each element contained in x.
Test your program with the following main() function:
def main(): print(replicate(7, [])) print(replicate(0, ['a', 'b', 'c'])) print(replicate(3, ['a'])) print(replicate(3, ['a', 'b', 'c'])) print(replicate(4, [1, 2, 3, 4]))
The expected program output should be:
[] [] ['a', 'a', 'a'] ['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c', 'c'] [1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4]
The Fibonacci sequence is:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ...
The sequence starts with 0 and 1. Any number that follows is calculated by adding the previous two numbers.
Write a program calledfibo.py. Define in this program a function called fibo(n) that returns a list with the first n Fibonacci numbers.
Test your program with the following main() function:
def main(): print(fibo(0)) print(fibo(1)) print(fibo(2)) print(fibo(5)) print(fibo(10)) print(fibo(20)) print(fibo(30)) print(fibo(100))
The expected program output should be:
[] [0] [0, 1] [0, 1, 1, 2, 3] [0, 1, 1, 2, 3, 5, 8, 13, 21, 34] [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181] [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229] [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986, 102334155, 165580141, 267914296, 433494437, 701408733, 1134903170, 1836311903, 2971215073, 4807526976, 7778742049, 12586269025, 20365011074, 32951280099, 53316291173, 86267571272, 139583862445, 225851433717, 365435296162, 591286729879, 956722026041, 1548008755920, 2504730781961, 4052739537881, 6557470319842, 10610209857723, 17167680177565, 27777890035288, 44945570212853, 72723460248141, 117669030460994, 190392490709135, 308061521170129, 498454011879264, 806515533049393, 1304969544928657, 2111485077978050, 3416454622906707, 5527939700884757, 8944394323791464, 14472334024676221, 23416728348467685, 37889062373143906, 61305790721611591, 99194853094755497, 160500643816367088, 259695496911122585, 420196140727489673, 679891637638612258, 1100087778366101931, 1779979416004714189, 2880067194370816120, 4660046610375530309, 7540113804746346429, 12200160415121876738, 19740274219868223167, 31940434634990099905, 51680708854858323072, 83621143489848422977, 135301852344706746049, 218922995834555169026]
In statistics, the standard deviation σ is a measure of how spread out numbers are. It has the following formula:
Where x is the arithmetic mean and is defined as follows:
Write a program called deviation.py. Define in this program a function called deviation(x) that returns the standard deviation of the list of numbers contained in x.
Test your program with the following main() function:
def main(): print(deviation([42])) print(deviation([10, 20])) print(deviation([1, 2, 3, 4, 5])) print(deviation([7, 7, 7, 7, 7, 7, 7])) print(deviation([32, 88, 20, 26, 14, 24, 26, 44, 14, 94, 94, 72, 8, 46, 92, 50, 38, 56, 60, 84]))
The expected program output should be:
0.0 5.0 1.4142135623730951 0.0 28.673855687716646
Write a program called dropevery.py. Define in this program a function called dropevery(n, x) that takes two arguments: an integer number n, where n ≥ 0, and a list x. It returns a new list that drops every n-th element from x.
Test your program with the following main() function:
def main(): print(dropevery(5, [])) print(dropevery(4, [1, 2, 3, 4])) print(dropevery(2, [1, 2, 3, 4, 5, 6, 7, 8])) print(dropevery(2, [1, 2, 3, 4, 5, 6, 7, 8, 9])) print(dropevery(3, ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'])) print(dropevery(20, ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'])) print(dropevery(1, ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']))
The expected program output should be:
[] [1, 2, 3] [1, 3, 5, 7] [1, 3, 5, 7, 9] ['a', 'b', 'd', 'e', 'g', 'h', 'j'] ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'] []
Write a program called compress.py. Define in this program a function called compress(x) that takes a list x as its argument. If x contains consecutive repeated elements, they should be replaced with a single copy of that element. The order of the elements should not be changed.
Test your program with the following main() function:
def main(): print(compress(['a', 'a', 'a', 'a', 'b', 'c', 'c', 'a', 'a', 'd', 'e', 'e', 'e', 'e'])) print(compress(['a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', 'a'])) print(compress(['a', 'b', 'c', 'd'])) print(compress([]))
The expected program output should be:
['a', 'b', 'c', 'a', 'd', 'e'] ['a'] ['a', 'b', 'c', 'd'] []
Write a program called wordcount.py. Define in this program a function called wordcount(infile) that takes a string with the name of an input file infile and returns the number of lines, number of words, and number
of characters in the file.
To test your program, create a file called crocodile.txt with the following content:
HOW DOTH THE LITTLE CROCODILE Lewis Carroll How doth the little crocodile Improve his shining tail, And pour the waters of the Nile On every golden scale! How cheerfully he seems to grin, How neatly spread his claws, And welcome little fishes in With gently smiling jaws!
Add the following main() function to your program:
def main(): print(wordcount('crocodile.txt'))
The expected output after running the program should be:
(12, 47, 274)
This is because the file crocodile.txt has 12 lines, 47 words, and 274 characters. NOTE: These numbers may vary slightly depending of the operating system being used.
Write a program called reverse.py. Define in this program a function called reverse(infile, outfile) that takes two arguments: a string with the name of the input file infile and a string with the name of the output file outfile. The function should write in outfile each of the lines contained in infile but in reversed order. The function should return nothing.
To test your program, create a file called speak.txt with the following content:
SPEAK ROUGHLY Lewis Carroll Speak roughly to your little boy, And beat him when he sneezes: He only does it to annoy, Because he knows it teases. Chorus Wow! wow! wow! I speak severely to my boy, I beat him when he sneezes; For he can thoroughly enjoy The pepper when he pleases!
Add the following main() function to your program:
def main(): reverse('speak.txt', 'speak_reverse.txt')
After running your program, the contents of the file speak_reverse.txt should be:
The pepper when he pleases! For he can thoroughly enjoy I beat him when he sneezes; I speak severely to my boy, Wow! wow! wow! Chorus Because he knows it teases. He only does it to annoy, And beat him when he sneezes: Speak roughly to your little boy, Lewis Carroll SPEAK ROUGHLY
Write a program called linenum.py. Define in this program a function called linenum(infile, outfile) that takes two arguments: a string with the name of the input file infile and a string with the name of the output file outfile. The function should write in outfile each of the lines contained in infile but adding the line number along the left edge. The function should return nothing.
To test your program, create a file called bat.txt with the following content:
THE BAT Lewis Carroll Twinkle, twinkle, little bat How I wonder what you're at! Up above the world you fly Like a tea-tray in the sky.
Add the following main() function to your program:
def main(): linenum('bat.txt', 'bat_linenum.txt')
After running your program, the contents of the file bat_linenum.txt should be:
1: THE BAT 2: Lewis Carroll 3: 4: Twinkle, twinkle, little bat 5: How I wonder what you're at! 6: Up above the world you fly 7: Like a tea-tray in the sky.
Create a ZIP file called lists_files.zip containing only the ten programs you wrote (positives.py, dotproduct.py, replicate.py, fibo.py, deviation.py, dropevery.py, compress.py, wordcount.py, reverse.py and linenum.py).
To deliver the lists_files.zip file, please provide the following information:
If this activity was developed by a team of two people, only one person is required to deliver it. No activity will be accepted through e-mail or any other means.
Due date is Wednesday, April 8, all day up to midnight.
This activity will be evaluated using the following criteria:
| -10 | One or more programs don’t contain within comments the authors’ personal information. |
|---|---|
| DA | One or more programs were plagiarized. |
| 10-100 | Depending on the amount of problems that were solved correctly. |