This project will cover the basics of working in the Unix environment and a small introduction to Python. In this course, we will only be using Python 3. You may remotely connect to the SOE servers or use lab workstations as well as your own computer.
To get you familiarized with the automatic grading system, we will ask you to submit answers for problems 1 (buyLotsOfFruit) and 2 (shopSmart).
The project may seem simple, but this is a good thing: learning the basics of Python now will save you many headaches later in the course.
Take this easy project as an opportunity to learn Python.
Here is the code provided for this assignment: p0.zip.
This assignment should be submitted with the filename solution.zip HERE.
Please use the command line zip tool to make sure your submission gets zipped correctly:
zip solution.zip buyLotsOfFruit.py shopSmart.py
For these submissions, unzip should directly yield the source files and not a directory named "solution" or "pN". Note that this is counter to standard conventions when sending a zip file to a human, but easier for the autograder.
After submissions, the autograder will grade your submission and report the result back to you. Do not close the tab or you will not be able to see your score. You can submit as many times as you want. However, if we find you continually making tiny changes instead of testing locally, then we will deduct points. Any attempts to trick the autograder is considered cheating.
There are many great resources online for learning Unix and Python.
Being familiar with a powerful text editor can make a surprising difference. In the programming world, there are two text editors that have stayed on the top for over 30 years. Vi (Vim) and Emacs are two very powerful terminal-based text editors (although both have GUI versions). The arguments about which one is better have been going on for decades and will never be resolved. In truth, they are both amazing editors and will greatly increase your productivity once you learn how to use them. There are also many online resources for each:
Git is currently the most popular Version Control System, period. Learning how to use source control is a must for all programmers in today's world. We strongly encourage all students to use source control for their coursework. Of course, keep your repositories private so other students cannot see. Here are several resources for learning how to use git:
Python is one of the most popular programming languages. So, there are many online resource available for it. Here are just a few useful resources:
For this assignment, you will be filling in two methods in two different Python files.
Implement the buyLotsOfFruit function in the buyLotsOfFruit.py file.
This function will take a list of (fruit, weight) tuples and returns the cost of your list.
If there is some fruit in the list which doesn't appear in FRUIT_PRICES, your function should print an error message and return None (which is like null in C and Java).
Please do not change the FRUIT_PRICES dict.
Implement the shopSmart function in the shopSmart.py file.
This function takes two arguments:
orderList - Like the kind passed in to buyLotsOfFruit().
fruitShops - A list of FruitShop.
FruitShop where your total order costs the least amount.
Don't change the file name or variable names, please.
Note that we will provide the shop.py implementation as a "support" file, so you don't need to submit yours.
Here are some common problems (and their solutions) that new Python students have:
Problem:
You get the following error when running your program:
ImportError: No module named py
Solution:
When using import, do not include the ".py" from the filename.
For example, you should say: import shop
not: import shop.py.
Problem:
You get the following error when running your program:
NameError: name 'my_variable' is not defined
Solution:
To access a member of a module, you have to type module_name.member_name, where module_name is the name of the .py file,
and member_name is the name of the variable (or function) you are trying to access.
Problem:
You get the following error when running your program:
TypeError: 'dict' object is not callable
Solution:
Dictionary looks up are done using square brackets: [ and ]. NOT parenthesis: ( and ).
Problem:
You get the following error when running your program:
ValueError: too many values to unpack
Solution:
Make sure the number of variables you are assigning to a variable or in a for loop matches the number of elements in each item of the list.
Similarly for working with tuples.
For example, if pair is a tuple of two elements (e.g. pair = ('apple', 2.0)) then the following code would cause the "too many values to unpack error":
pair = ('apple', 2.0)
(a, b, c) = pair
Here is a problematic scenario involving a for loop:
pairList = [('apples', 2.00), ('oranges', 1.50), ('pears', 1.75)]
for fruit, price, color in pairList:
print('%s fruit costs %f and is the color %s' % (fruit, price, color))
Problem:
You get the following (or similar) error when running your program:
AttributeError: 'list' object has no attribute 'length'
Solution:
Finding length of lists is done using len(myList).