Lab 7 — Strings and Doctests

In this lab, you will write functions that operate on strings. For each function, you will write doctests.

Create a file called strings_and_tests.py and you will use this file for all the problems in this lab.

Exclaim

Juliette loves to type text messages with lots of punctuation. She’s very enthusiastic, so she’ll often repeat the exclamation a bunch… Here’s one of her recent text conversations:

Juliette: “Did you see Amanda Gorman at the inauguration?!?!?!?!” “Yes, her poem was great. Did you like it?” Juliette: “It was amazing!!!” “Agreed! And she is only 22. What will you have accomplished by the age of 22?” Juliette: ”…”

Juliette is getting tired of repeating the punctuation so much. Help her out by writing a Python function that does it for her! The function is exclaim(message, end, repeat):

• message: a string
• end: a string, the ending punctuation
• repeat: a number indicating the number of times to repeat the punctuation at the end of the message

The function should return the resulting message.

For example:

result = exclaim('Did you see Amanda Gorman at the inauguration', '?!', 6)
print(result)
> Did you see Amanda Gorman at the inauguration?!?!?!?!?!?!

result = exclaim('CS 110 is awesome','!', 5)
print(result)
> CS 110 is awesome!!!!!

1. Write a docstring for this function
2. Write a doctest for this function
3. Write the function and test it
4. In the main body of the file, call your function 1 time and print the results to the screen.

Remember that you can type triple double quotes """ in PyCharm, and then Return and Pycharm will fill in a template for the Docstring.

When writing doctests that return strings, use single quotes and not double quotes.

Spacing

Write a function spacing(word, number_of_spaces) that puts spaces between every letter of a word. The parameters are:

• word: a string
• number_of_spaces: an integer, representing the number of spaces to adding

The return value is a string with spaces between all the characters. For example:

If the number_of_spaces is less than zero, then treat it the same as if it was zero.

Call your spacing() function at least 5 times and print the results to the screen.

1. Write a docstring for this function
2. Write a doctest for this function
3. Write the function and test it
4. In the main body of the file, call your function 1 time and print the results to the screen.

Word Guess

Use the file word_guess.py to write your code for this problem.

Write a function, word_guess(guessed_word, secret_word, guess) that helps us play a word guessing game. The function takes in 3 paramters:

• guessed_word: a string representing what we’ve guessed so far in the word; unguessed letters represented by ”-”

• secret_word: a string representing the word we are trying to guess

• guess: a string representing the letter we are guessing this round

The function should return a string that represents our guessed word updated by the most recent guess.

Remember that strings are immutable, so the function needs to create a new string letter by letter.

Here are some examples of input and output

1. Write a docstring for this function
2. Write a doctest for this function
3. Write the function and test it
4. In the main body of the file, call your function 1 time and print the results to the screen.

Guessing game

This is an optional activity! Download guessing-game.zip. Take your code for the word_guess() function and put it inside the guessing_game.py file. See the directions at the top of guessing_game.py. Enjoy!

Don’t worry about understanding all the other code in guessing_game.py. But by the end of the course, you should be able to understand all this!

Lessons

What we want you to get from this lab:

• You understand how to use strings

• You can write functions that loop over strings and return strings

• You can clearly document your functions with docstrings

• You can write doctests and use them to test your functions

• You can figure out what went wrong when something unexpected happens

• Hopefully you had fun!

Points

Turn in a zip file that has your code.