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CSW8 W23 Project

Step 7 - “Restore” option

New functions needed:

  • load_menu_from_csv()

This function

  • reads data from a csv file, one line at a time
  • validates it by trying to create a menu
  • stores that data into the menu dictionary.

Advice: If you have trouble with your function, we recommend reviewing Section 9.6, and 9.7 on zyBooks.

To implement your function, you must import csv in the functions.py file. For more information, refer to zyBooks section 9.7. You should be able to reuse your code directly from LA 9.8.

The function requires the import csv as well as import os. NO OTHER import libraries/modules are allowed!

Note that while it is common for Python programmers to put import statements at the very top of their code, because of the way the autograder is implemented, you must do these imports inside the load_menu_from_csv function; put them right after the docstring. Putting them at the top of the file will cause you to lose points for use of a “global variable”.

Sample Menu File

Below are the contents of a CSV file that is used in the sample program flow below. This file has no empty rows (lines) and no bad (invalid) data. If it did, that row would counted as being invalid.

menu.csv

burrito,500,12.9,yes,2
rice bowl,400,14.9,no,3
margherita,800,18.9,no,2

Two other things you need to do:

The code to implement the R option is similar to the one for the option S. You’ll need:

  • Code in main.py to look for the R option and call load_helper, which must take these parameters: restaurant_menu_list and spicy_scale_map (this function doesn’t return anything; it just implements the program flow shown below).
  • The function definition for load_helper, which must go into functions.py.

Sample Program Flow

This example run has the user doing the following:

  • Starts by deleting all the dishes in current menu
  • Then attempting to restore data from a file
    • First attempt: using a bad file name (doesn’t end in .csv)
    • Second attempt: using a bad file name (ends in .csv, but file doesn’t exist)
    • Third attempt: successful
  • Then lists the menu to make sure they were indeed restored.
==========================
What would you like to do?
L - List
A - Add
U - Update
D - Delete
H - Display restaurant expense rating
S - Save the data to file
R - Restore data from file
Q - Quit this program
==========================
::: Enter a menu option
> D
You selected option D to > Delete.
Which dish would you like to delete?
Press A to delete the entire menu for this restaurant, M to cancel this operation
------------------------------------------
1. BURRITO
2. RICE BOWL
3. MARGHERITA
------------------------------------------
> A
::: WARNING! Are you sure you want to delete the entire menu ?
::: Type Yes to continue the deletion.
> Yes
Deleted the entire menu.
::: Press Enter to continue
==========================
What would you like to do?
L - List
A - Add
U - Update
D - Delete
H - Display restaurant expense rating
S - Save the data to file
R - Restore data from file
Q - Quit this program
==========================
::: Enter a menu option
> R
You selected option R to > Restore data from file.
::: Enter the filename ending with '.csv'.
> wrong_menu
WARNING: |wrong_menu| is an invalid file name!
::: Would you like to try again? Enter 'y' to try again.
> y
::: Enter the filename ending with '.csv'.
> missing_menu.csv
WARNING: |missing_menu.csv| was not found!
::: Would you like to load another file? Enter 'y' to try again.
> y
::: Enter the filename ending with '.csv'.
> wrong_menu.csv
WARNING: |wrong_menu.csv| contains invalid data!
The following rows from the file were not loaded:
[1, 2]
::: Would you like to try again? Enter 'y' to try again.
> y
::: Enter the filename ending with '.csv'.
> menu.csv
Successfully restored restaurant menu from |menu.csv|
::: Press Enter to continue
==========================
What would you like to do?
L - List
A - Add
U - Update
D - Delete
H - Display restaurant expense rating
S - Save the data to file
R - Restore data from file
Q - Quit this program
==========================
::: Enter a menu option
> L
You selected option L to > List.
::: What field would you like to list?
A - complete menu
V - vegetarian dishes only
::: Enter your selection
> A
You selected |A| to list |complete menu|.
------------------------------------------
1. BURRITO
* Calories: 500
* Price: 12.9
* Is it vegetarian: yes
* Spicy level: Low key spicy

2. RICE BOWL
* Calories: 400
* Price: 14.9
* Is it vegetarian: no
* Spicy level: Hot

3. MARGHERITA
* Calories: 800
* Price: 18.9
* Is it vegetarian: no
* Spicy level: Low key spicy

------------------------------------------

What if the CSV file has bad data?

Now, what if the CSV file has “invalid data” in it? “Invalid data” is only defined as data that would be flagged as an error by the get_new_menu_dish() function (example: bad name, bad format, etc…). For example, a dish with price 10.001, should not be considered to be “invalid” because that is not something that is validated by get_new_menu_dish().

For instance, if the CSV file being read is:

menu_somebad.csv

burrito,500,12.9,maybe,2
rice bowl,400,14.9,no,3
margherita,800,18.9,no,100

Notice that line (row) 1 has a bad (invalid) is_vegetarian (maybe) and that line 3 has a bad spicy_level (100 - that’s too hot!). The function load_from_csv() should update the menu dictionary with new dishes from line 2 only AND it should return a list that is [1, 3] (because lines 1 and 3 are the ones with invalid data in them).

Here’s a sample run for when a file, like the one above, is restored:

==========================
What would you like to do?
L - List
A - Add
E - Update
D - Delete
M - Show statistical data on
S - Save the data to file
R - Restore data from file
Q - Quit this program
==========================
::: Enter a menu option
> r
You selected option R to > Restore data from file.
::: Enter the filename ending with '.csv'.
> menu_somebad.csv
WARNING: |menu_somebad.csv| contains invalid data!
The following rows from the file were not loaded:
[1, 3]
::: Would you like to try again? Enter 'y' to try again.

A hint

If the Save option from the previous step is working correctly, the file you wrote into using that option should work perfectly with your new Restore option.

When saving and restoring, your entire menu information should be loaded properly.

You may want to try saving, restoring, and listing a few times to make sure that everything works.

Checkpoint 2

After finishing this step, you are ready for Checkpoint 2.

Note that you may need to add a few stubs for functions that are part of the remainder of the project. See the Checkpoint 2 instructions for more information.