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For the latest content please see the repository at:
https://umd-ischool-inst326.github.io/inst326/
Background
An online magnet seller sells a particular magnet at a base price of $0.75 but offers bulk pricing depending on the quantity of magnets ordered, as follows:
| Quantity | Price |
|---|---|
0–49 |
$0.75 |
50–99 |
$0.72 |
100–999 |
$0.70 |
1000+ |
$0.67 |
Instructions
Write a script using the template below. Replace the comment in the template with a function called get_cost() that calculates the cost of an order of magnets using the pricing scheme in the table above. Your function should take a non-negative number of magnets (an integer) as its only argument. It should return [1] a float indicating the cost of the order in dollars.
If the number of magnets is less than zero, your function should raise a ValueError.
Your function should have a docstring that briefly states
-
what the function does
-
what argument(s) it requires
-
what kind of value it returns and what this value means
-
what error(s) it raises and what they mean
The template code is designed to take one integer as a command-line argument. It validates this argument, converts it to an integer, invokes your function, and prints a string containing the value returned by your function.
""" Calculate the price of an order of magnets according to a bulk
pricing scheme. """
import sys
# replace this comment with your implementation of the get_cost() function
if __name__ == "__main__":
try:
magnets = int(sys.argv[1])
except IndexError:
sys.exit("this program expects a number of magnets as a command-line"
" argument")
except ValueError:
sys.exit("could not convert " + sys.argv[1] + " into an integer")
print(get_cost(magnets))Running your program
To run your program, open a terminal and ensure you are in the directory where your script is saved. At the command prompt, type python3 (Windows users, type python instead) followed by a space, the name of your script, another space, and an integer. For example, if your script were called bulk_pricing.py and you wanted to calculate the cost of ordering 75 magnets, you would type
python3 bulk_pricing.py 75