giorosati / 3-arrays-and-maps-giorosati

Project 3: Arrays & Maps

Please complete the following 3 functions. You can test by running the pytest or python3 commands:

• To run just the main code for one problem: python3 frequency.py
• To run the tests for one problem: pytest frequency_test.py
• To run all the tests prior to submission: pytest

Files that should (& shouldn't!) be changed

You SHOULD implement your problem solutions in the following files:

• frequency.py
• multiply.py
• tic_tac_toe.py

You SHOULD NOT modify the following files:

• anything in the files folder
• frequency_test.py
• multiply_test.py
• tic_tac_toe_test.py

Looking for additional practice problems to prepare for the exam? Checkout:

• programs in the practice folder

Problem 1: Word Frequency

Implement a function word_frequencies that takes a string filename as a parameter and returns a dictionary mapping each word in the text file to the total number of times it occurs. All letters should be treated as lower case, and both punctuation and numbers should be ignored (best practice is to replace with a space). Letters separated by apostrophes should be left together (for example, don't becomes dont). Your solution may use string & file functions.

Example call

print_map_by_value(word_frequencies("files/turing.txt"))

Outputs

    10 the
     4 code
     3 of
     2 turing
     2 and
     2 at
     2 secret
     2 war
     2 enigma
     1 imitation
     1 game
     1 based
     1 on
     1 real
     1 life
     1 story
     1 legendary
     1 cryptanalyst
     1 alan
     1 film
     1 portrays
     1 nail
     1 biting
     1 race
     1 against
     1 time
     1 by
     1 his
     1 brilliant
     1 team
     1 breakers
     1 britains
     1 top
     1 government
     1 cypher
     1 school
     1 bletchley
     1 park
     1 during
     1 darkest
     1 days
     1 world
     1 ii
     1 true
     1 was
     1 man
     1 who
     1 cracked
     1 behind
     1 every
     1 is
     1 an
     1 unlock
     1 win

Hint: Looking for how to remove punctuation? See https://www.techiedelight.com/remove-punctuations-string-python/

Note: If you would like an extra challenge with MESSY real world data, you can try the included test_austen() challenge. This is an entire Jane Austen book that you can work on cleaning to find the word frequencies on. It will not display the entire dictionary in the console, you would need to find another way to check the data. This can take a week or more of extra time debugging, researching, and manipulating the data to match the expected output exactly. If you would like to opt into this additional challenge (recommended for those interested in Data Science), uncomment the test_austen() in frequency_test.py and use the austen file as well in frequency.py. Happy Coding!

Problem 2: Multiplication Table

Write a function called multiplication_table that takes a width, height, & scaling factor as parameters and returns a two-dimensional array multiplication table scaled by the scaling factor. You should not be using any functions other than range, len, or append in implementing your solution.

Example calls	Returns
print_2D(multiplication_table(5, 3, 1))	[1, 2, 3, 4, 5] [2, 4, 6, 8, 10] [3, 6, 9, 12, 15]
print_2D(multiplication_table(5, 3, 2))	[2, 4, 6, 8, 10] [4, 8, 12, 16, 20] [6, 12, 18, 24, 30]

Hint: Looking to initialize your array? Try a list comprehension: [ [ 0 for i in range(w) ] for i in range(h) ]. The code [[0]*w]*h WILL NOT work!

Problem 3: DID I WIN TIC-TAC-TOE?

Write a function did_I_win_2D that takes a string player name and a 2-dimensional 3 x 3 array as parameters and returns whether the player won the game.

Example calls	Returns
b = [["X", "O", "O"]] * 3 did_I_win_2D("X", b)	True
b = [["X", "O", "O"]] * 3 did_I_win_2D("O", b)	True
b = [ ['O', 'O', 'X'], ['O', 'X', 'O'], ['X', 'O', 'O'] ] did_I_win_2D("X", b)	True
b = [ ['O', 'O', 'X'], ['O', 'X', 'O'], ['X', 'O', 'O'] ] did_I_win_2D("O", b)	False

Hint: What does a boolean accumulator / aggregator variable look like?

Getting started

Develop in an IDE

You will need to install PyCharm (or another IDE), git, and pytest. PyCharm has some built-in git support.

Testing

Many of the tests are failing right now because the functions aren't outputting the correct information. Fixing this will make the tests pass & turn green.

Setup

repl.it or command line

To use pytest on repl.it, install it first:

pip3 install pytest

To install pytest on the command line for running on a laptop (using a linux or unix based command-line like MacOS):

sudo -H pip3 install pytest

Pycharm

If using PyCharm, you may need to fix your project setup.

• Open the Settings/Preferences | Tools | Python Integrated Tools settings dialog.
• In the Default test runner field select pytest.
• Click OK to save the settings.

VS Code

If using VS Code, you may need to configure your pytest settings.

• Open a python (.py) file
• In the testing panel, select the Configure Pytests button
• Select .root directory for the testing route
• Refresh the panel if needed if tests are not discovered

Run commands

To run just the main code for one problem:

python3 frequency.py

To run the tests for one problem:

pytest frequency_test.py

To run all the tests prior to submission:

pytest