PROBLEM $3$

In this python problem, we redesign the inventory program for Trish's bookstore using dictionaries. Note: We will be continuing this redesign in Lab $10.$

Copy the starter code Lab$09$P$3-$starter.py to a file named Lab$09$P$3.$py$.$

Remember in Lab $08,$ you used a list of lists to store the item information in the inventory system before writing it out to a file. You will change that now so that you are keeping the information in three dictionaries instead.

There are three TODO comments:

$$ At the first TODO comment, create three empty directories named inventory$\_$counts, inventory$\_$costs and inventory$\_$categories.

$$ At the second TODO comment, update the dictionaries with the user entered data. Use the item$\_$name as the key in all dictionaries and store the appropriate data.

o For example, if the user first entered the item name "Science Books" with an item count of $10,$ a unit cost of $12\mathrm{.}95,$ and a category "Book" this is what the dictionaries would look like:

inventory$\_$counts $=\{"$Science Books": $10\}$

inventory$\_$costs $=\{"$Science Books": $12\mathrm{.}95\}$

inventory$\_$categories $=\{"$Science Books": "Book"$\}$

$$ At the third TODO comment, print the dictionaries.

Same output:

Welcome to Trish's Inventory Input System

Enter the item name: Science Book

Enter the item count: $8$

Enter the unit cost: $14\mathrm{.}99$

Enter the category: Book

Enter another item? $($y$/$n$)$ y

Enter the item name: Monopoly

Enter the item count: $10$

Enter the unit cost: $17\mathrm{.}95$

Enter the category: Game

Enter another item? $($y$/$n$)$ y

Enter the item name: Die Hard

Enter the item count: $7$

Enter the unit cost: $5\mathrm{.}00$

Enter the category: DVD

Enter another item? $($y$/$n$)$ n

Inventory counts: $\{\text{'}$Science Book': $8,$ 'Monopoly': $10,$ 'Die Hard': $7\}$

Inventory costs: $\{\text{'}$Science Book': $14\mathrm{.}99,$ 'Monopoly': $17\mathrm{.}95,$ 'Die Hard': $5\mathrm{.}0\}$

Inventory categories: $\{\text{'}$Science Book': 'Book', 'Monopoly': 'Game', 'Die Hard': $\text{'}$DVD$\text{'}\}$

Submit the program file Lab$09$P$3.$py to Blackboard for credit. Sample output:

Welcome to Trish's Inventory Input System

Enter the item name: Science Book

Enter the item count: $8$

Enter the unit cost: $14\mathrm{.}99$

Enter the category: Book

Enter another item? $($y$/$n$)$ y

Enter the item name: Monopoly

Enter the item count: $10$

Enter the unit cost: $17\mathrm{.}95$

Enter the category: Game

Enter another item? $($y$/$n$)$ y

Enter the item name: Die Hard

Enter the item count: $7$

Enter the unit cost: $5\mathrm{.}00$

Enter the category: DVD

Enter another item? $($y$/$n$)$ n

Inventory counts: $\{\text{'}$Science Book': $8,$ 'Monopoly': $10,$ 'Die Hard': $7\}$

Inventory costs: $\{\text{'}$Science Book': $14\mathrm{.}99,$ 'Monopoly': $17\mathrm{.}95,$ 'Die Hard': $5\mathrm{.}0\}$

Inventory categories: $\{\text{'}$Science Book': 'Book', 'Monopoly': 'Game', 'Die

Hard': $\text{'}$DVD$\text{'}\}$CATEGORY$\_$LIST $=[\text{'}$Book$\text{'},\text{'}$DVD$\text{'},$ 'Game'$]$

def main$()$:

# TODO $-$ Create three empty dictionaries named inventory$\_$counts,

# inventory$\_$costs, and inventory$\_$categories

print$("$Welcome to Trish's Inventory Input System"$)$

while True:

item$\_$name $=$ get$\_$item$\_$name$()$

item$\_$count $=$ get$\_$item$\_$count$()$

unit$\_$cost $=$ get$\_$unit$\_$cost$()$

category $=$ get$\_$category$()$

# TODO $-$ Add the item data to the three dictionaries. Use the item$\_$name

# as a key for all dictionaries.

# $-$ Add the item$\_$count data as a value associated with the key

# item$\_$name in inventory$\_$counts.

# $-$ Add the unit$\_$cost data as a value associated with the key

# item$\_$name in inventory$\_$costs.

# $-$ Add the category data as a value associated with the key

# item$\_$name in inventory$\_$categories.

answer $=\text{'}\text{'}$

while answer $!=\text{'}$y$\text{'}$ and answer $!=\text{'}$n$\text{'}$:

answer $=$ input$(\text{'}$Enter another item? $($y$/$n$)\text{'})$

answer $=$ answer.lower$()$

if answer $!=\text{'}$y$\text{'}$ and answer $!=\text{'}$n$\text{'}$:

print$(\text{'}$Enter y or n to continue.$\text{'})$

if answer $==\text{'}$n$\text{'}$:

break

# TODO $-$ Print the three dictionaries as shown in assignment's

# sample output.

def get$\_$item$\_$name$()$:

# Get item name

item$\_$name $=$ input$(\text{'}$Enter the item name: $\text{'})$

return item$\_$name

def get$\_$item$\_$count$()$:

# Get item count

while True:

try:

item$\_$count $=$ int$($input$(\text{'}$Enter the item count: $\text{'}))$

if item$\_$count $<mtext\; id="EditorElement\_757089"></mtext><mn\; id="EditorElement\_757090">0</mn>$:

print$(\text{'}$Item count must be $0$ or greater.$\text{'})$

else:

break

except:

print$(\text{'}$Item count must be an integer.$\text{'})$

return item$\_$count

def get$\_$unit$\_$cost$()$:

# Get unit cost

while True:

try:

unit$\_$cost $=$ float$($input$(\text{'}$Enter the unit cost: $\text{'}))$

if unit$\_$cost $<mtext\; id="EditorElement\_757440"></mtext><mn\; id="EditorElement\_757441">0</mn>$:

print$(\text{'}$Unit cost must be $0$ or greater.$\text{'})$

else:

break

except:

print$(\text{'}$Unit cost can only contain digits and a single decimal point.$\text{'})$

return unit$\_$cost

def get$\_$category$()$:

while True:

category $=$ input$(\text{'}$Enter the category: $\text{'})$

if category not in CATEGORY$\_$LIST:

print$($f$\text{'}$Category must be in this list: $\{$CATEGORY$\_$LIST$\}\text{'})$

else:

break

return category

main$()$