Homework 5b — Building Dictionaries

1. Scheduling

Write a program in scheduling.py that takes

• a file containing names (one name per line)
• a file containing time slots (one time per line)

The program assigns each person in the first file to a time slot in the second file.

In actual practice, you might choose to randomly assign the individuals to the time slots, but for the purposes of grading this activity, simply assign each person to the next available time slot, in the order they are listed. So the first name is assigned to the first time slot, the second person to the second time slot, and so forth.

After each person is assigned a time slot, allow the user to enter the names of participants in order to find their assigned time. If the name entered is not assigned, indicate that the person has no assignment.

Follow the formatting and prompts of the example.

Example

students.txt

Juan
Julia
Robert

timeslots.txt

10:00 AM
10:30 AM
11:30 AM
1:00 PM

python scheduling.py students.txt timeslots.txt
Name: Julia
Julia is assigned 10:30 AM
Name: Charles
Charles is not assigned a timeslot
Name: Robert
Robert is assigned 11:30 AM
Name:

Strategy

We recommend approaching this problem with the following steps:

1. Fill in scheduling.py with basic starter code: import sys, def main..., if __name__..., etc.
2. Write a function to get a list of lines from a file.
3. Write a function that strips all the newlines from the ends of a list of lines.
   1. Using print statements or the debugger, make sure these functions work as expected.
4. Write a function that takes a list of people and a list of times and returns a dictionary that maps people to times. Use the guide for help.
   1. Again test your code to make sure this function works as expected.
5. Finish the program using these pieces.
   1. Write additional functions as necessary.

You can test your program on your own using:

python scheduling.py students.txt timeslots.txt

2. Shopping Carts

Write a program in shopping_total.py that takes

• A CSV file representing the contents of a shopping cart
  • Each line has an item name and quantity
• A CSV file with item names and prices

The program then prints out the total price for the given shopping cart (rounded to 2 decimal places).

Follow the format shown in the example.

Example

items.csv

potatoes,5.4
bananas,3.1
pizza,1

prices.csv

strawberries,2.98
watermelon,4.37
plums,1.97
potatoes,0.43
bananas,0.63
pizza,6.96
milk,2.63

python shopping_total.py items.csv prices.csv
The total is $11.24

Strategy

We recommend approaching this problem using the following steps:

1. Fill in scheduling.py with basic starter code: import sys, def main..., if __name__..., etc.
2. Write a function that reads a list of lines from a file.
3. Write a function that turns a list of CSV lines into a dictionary that maps the first token to the second token.
4. Write a function that takes a dictionary of items-to-quantities and a dictionary of items-to-prices and compute the total.
5. Finish the program.

You can test your program on your own using:

python shopping_total.py items.csv prices.csv

Tests

Be sure you can pass the tests before you turn in the assignment. Review the guide on using pytest if you need to review using pytest and what to do if a test fails.

Grading

Manual grading will focus on decomposition, fluency, and use of dictionaries.