def create(ourSkewer, args):
"""
Create the skewer that will hold the food.
Arguments:
ourSkewer - the Skewer object
args - a string containing the size to create.
Example:
create 10 # creates a skewer that can hold 10 elements
"""
# make sure the size is valid
try:
size = int(args[0])
if size < 1:
raise skewer_exception.SkewerException(
"Skewer size must be greater than 0")
except ValueError as e:
print("The size of the skewer must be a valid integer")
return None
# force delete any pre-existing skewer
if ourSkewer:
ourSkewer = skewer.close(ourSkewer)
ourSkewer = skewer.mkSkewer(size)
print("Skewer created.")
return ourSkewer
def add(ourSkewer, args):
"""
Add a specified item to the skewer
Arguments:
ourSkewer - the Skewer object
args - The name of the item to add
Example:
add Onion # add an Onion to the skewer
"""
if len(args) < 1:
help(None, None)
return
name = args[0]
# Check that the name is in the list of valid foods.
if name not in food.FOODS:
raise skewer_exception.SkewerException(
"Kebab can hold the following foods: " + str(food.FOODS))
skewer.add(ourSkewer, name)
if ourSkewer != None:
print(name, "successfully added to the skewer.")
else:
print(name, "was not successfully added to the skewer.")
def top(skwr):
"""
Gets the name of the top item on the skewer.
Arguments:
skwr - the Skewer instance
Exceptions:
skewer_exception.SkewerException - no item was on the skewer, or it doesn't exist
Returns: The name of the food item (string) on the front
"""
if skwr == None:
raise skewer_exception.SkewerException(
"Cannot get top item from skewer that does not exist")
if kebab_spot.emptyKebab(skwr.top):
raise skewer_exception.SkewerException(
"Cannot get top item from an empty skewer!")
return skwr.top.item.name
def destroy(skwr):
"""
Close and destroy the skewer, if it exists
Exceptions:
skewer_exception.SkewerException - cannot destroy the skewer because it doesn't exist
"""
if skwr == None:
raise skewer_exception.SkewerException(
"Cannot destroy the skewer if it does not exist")
close(skwr)
def calories(skwr):
"""
This function takes the paramter of the skewer and uses it to test for an
empty skewer and returns the value of calories.
"""
if skwr == None:
raise skewer_exception.SkewerException( \
"Cannot get calories from skewer if it does not have anything")
return kebab_spot.calories(skwr.top)
def remove(skwr):
"""
Remove the front item from the skewer.
Arguments:
skwr - the Skewer instance
Exceptions:
skewer_exception.SkewerException - no item was on the skewer, or it doesn't exist
"""
if skwr == None:
raise skewer_exception.SkewerException(
"Cannot eat item from skewer that does not exist")
if kebab_spot.emptyKebab(skwr.top):
raise skewer_exception.SkewerException(
"Cannot get item from an empty skewer!")
# Un-draw the food item.
skwr.ui.remove()
# "Pop" the item off the skewer.
skwr.top = skwr.top.succ
def close(skwr):
"""
Close the UI if the skewer is deleted.
Arguments:
skwr - the Skewer instance being deleted.
Exceptions:
skewer_exception.SkewerException - cannot close the skewer because it doesn't exist
"""
if skwr == None:
raise skewer_exception.SkewerException(
"Cannot close the skewer if it does not exist")
skwr.ui.close()
def size(skwr):
"""
Get the number of elements on the skewer.
Arguments:
skwr - the Skewer instance
Returns: the number of elements (int)
Exceptions:
skewer_exception.SkewerException - skewer doesn't exist
"""
if skwr == None:
raise skewer_exception.SkewerException( \
"Cannot get size from skewer that does not exist")
return kebab_spot.size(skwr.top)
def add(skwr, name):
"""
Add a food item to the skewer
Arguments:
skwr - the Skewer instance
name - the string name of the food item
Exceptions:
skewer_exception.SkewerException - item could not be added because skewer doesn't exist
"""
if skwr == None:
raise skewer_exception.SkewerException(
"Cannot add item to skewer that does not exist")
if skwr.top == kebab_spot.NONE_NODE or kebab_spot.size(
skwr.top) < skwr.capacity:
obj = food.mkFood(name)
# Create new KebabSpot and "push" it on the skwr.
skwr.top = kebab_spot.mkKebabSpot(obj, skwr.top)
# Have the food appear in the right spot.
skwr.ui.add(skwr.top)
else:
raise skewer_exception.SkewerException(
"Cannot add item to a full skewer!")
def asString(skwr):
"""
Return a string representation of the items on the skewer.
Arguments:
skwr - the Skewer instance
Returns: A string containing all the items on the skewer,
from front to back, comma separated, and surrounded with
square brackets.
"""
if skwr == None:
raise skewer_exception.SkewerException( \
"Cannot get items from skewer if it does not exist")
return "[ " + kebab_spot.stringEm(skwr.top) + " ]"
def has(skwr, name):
"""
Is a particular food item on the skewer?
Arguments:
skwr - the Skewer instance
name - the name (string) of the food item to search for
Returns: True if the item is on the skewer, False if not.
Exceptions:
skewer_exception.SkewerException - skewer does not exist
"""
if skwr == None:
raise skewer_exception.SkewerException( \
"Cannot tell if skewer has something on it if it does not exist")
return kebab_spot.has(skwr.top, name)
def isVeggie(skwr):
"""
Are there only vegetables on the skewer?
Arguments:
skwr - the Skewer instance
Returns: True if there are only veggies on the skewer,
False if not.
Exceptions:
skewer_exception.SkewerException - skewer does not exist
"""
if skwr == None:
raise skewer_exception.SkewerException( \
"Cannot tell if veggie if the skewer does not exist")
return kebab_spot.isVeggie(skwr.top)
def mkSkewer(capacity):
"""
Construct a Skewer instance.
Arguments:
capacity - the maximum number of items it can hold
Exceptions:
skewer_exception.SkewerException - a capacity less than 1 was specified.
"""
if capacity < 1:
raise skewer_exception.SkewerException( \
"Skewers must have positive capacity!" )
result = Skewer()
result.top = kebab_spot.NONE_NODE
result.capacity = capacity
result.ui = kebab_graphics.SkewerUI(capacity)
return result
def has(ourSkewer, args):
"""
Checks if the skewer holds a certain item.
Arguments:
ourSkewer - the Skewer object
args - the name of the item to search for
Example:
has Onion # does the skewer have an Onion on it?
"""
if len(args) < 1:
help(None, None)
return
name = args[0]
if skewer.has(ourSkewer, name):
print(name, "does exist on the Skewer.")
else:
raise skewer_exception.SkewerException(
"Skewer size must be greater than 0")