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Gary Gibson
5,011 PointsHow to catch a value error on the bottom of this shopping list script?
Kenneth said to catch value errors at the bottom of this script. I've tried a few times but can't get it to work properly.
shopping_list = []
def show_help():
print("\nSeparate each item with a comma.")
print("""Type 'done' to quit, 'show' to see the curent list,
and 'help' to get this message as a reminder.""")
def show_list():
count = 1
for i in shopping_list:
print("{}: {}".format(count, i))
count += 1
print("Enter items for your shopping list.")
show_help()
while True:
new_stuff = input("Please enter an item. ")
if new_stuff == "quit":
print("\nHere's your list.")
show_list()
break
elif new_stuff == "help":
show_help()
continue
elif new_stuff == "show":
show_list()
continue
else:
new_list = new_stuff.split(",")
index = input("If you want to add this to a certain spot, enter the appropriate number. Or juts hit 'enter' to add it to the end of the list. Currently {} items in the list".format(len(shopping_list)))
if index:
spot = int(index) - 1
for item in new_list:
shopping_list.insert(spot, item.strip())
spot += 1
else:
for item in new_list:
shopping_list.append(item.strip())
6 Answers
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsWhat video or challenge is this? I suspect he wants you to use a try/except block: https://docs.python.org/2/tutorial/errors.html
Gary Gibson
5,011 PointsI didn't include it here.
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsCan you post the version that includes it?
Gary Gibson
5,011 Pointsshopping_list = []
def show_help():
print("\nSeparate each item with a comma.")
print("""Type 'done' to quit, 'show' to see the curent list,
and 'help' to get this message as a reminder.""")
def show_list():
count = 1
for i in shopping_list:
print("{}: {}".format(count, i))
count += 1
print("Enter items for your shopping list.")
show_help()
while True:
new_stuff = input("Please enter an item. ")
if new_stuff == "quit":
print("\nHere's your list.")
show_list()
break
elif new_stuff == "help":
show_help()
continue
elif new_stuff == "show":
show_list()
continue
else:
new_list = new_stuff.split(",")
try:
index = input("If you want to add this to a certain spot, enter the appropriate number. Or juts hit 'enter' to add it to the end of the list. Currently {} items in the list".format(len(shopping_list)))
except ValueError:
print("Please enter a number.")
else:
if index:
spot = int(index) - 1
for item in new_list:
shopping_list.insert(spot, item.strip())
spot += 1
else:
for item in new_list:
shopping_list.append(item.strip())
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsAnd which challenge or video is this for?
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsHere is my version:
shopping_list = []
def remove_item(idx):
index = idx - 1
item = shopping_list.pop(index)
print("Remove {}.".format(item))
def show_help():
print("\nSeparate each item with a comma.")
print("Type DONE to quit, SHOW to see the current list, and HELP to get this message, REMOVE to delete an item")
def show_list():
count = 1
for item in shopping_list:
print("{}: {}".format(count, item))
count += 1
print("Give me a list of things you want to shop for.")
show_help()
while True:
new_stuff = input("> ")
if new_stuff == "DONE":
print("\nHere's our list:")
show_list()
break
elif new_stuff == "HELP":
show_help()
continue
elif new_stuff == "SHOW":
show_list()
continue
elif new_stuff == "REMOVE":
idx = input("Which item? Tell me the number. ")
remove_item(int(idx))
else:
new_list = new_stuff.split(",")
index = input("Add this at a certain spot? Press enter for the end of the list, " "or give me a number. Currently {} items in the list. ".format(len(shopping_list)))
while True: #making a loop, so they can keep trying til they get it right
if len(index): ## if they didn't just hit "enter"
try:
int(index) ## if index can be converted to an int, it will keep going, otherwise it raise a ValueError and jump to the except block
spot = int(index) - 1
for item in new_list:
shopping_list.insert(spot, item.strip())
spot += 1
break ##exiting this while loop because we succeeded this task
except ValueError:
index = input("That wasn't a number. Try giving me a number again for a spot, or press enter for the end of the list")
## in this case it's going to loop back again to line 41, test to see if they hit enter and test to see if it's an int
else: ## if index doesn't have a length, and they just hit "enter" we put their items at the end
for item in new_list:
shopping_list.append(item.strip())
break
Gary Gibson
5,011 PointsI don't know what I did, but now this code works:
shopping_list = []
def show_help():
print("\nSeparate each item with a comma.")
print("""Type 'done' to quit, 'show' to see the curent list,
and 'help' to get this message as a reminder.""")
def show_list():
count = 1
for i in shopping_list:
print("{}: {}".format(count, i))
count += 1
print("Enter items for your shopping list.")
show_help()
while True:
new_stuff = input("Please enter an item. ")
if new_stuff == "quit":
print("\nHere's your list.")
show_list()
break
elif new_stuff == "help":
show_help()
continue
elif new_stuff == "show":
show_list()
continue
elif new_stuff == "":
print("Nothing? Are you sure?")
else:
new_list = new_stuff.split(",")
try:
index = input("If you want to add this to a certain spot, enter the appropriate number. Or juts hit 'enter' to add it to the end of the list. Currently {} items in the list".format(len(shopping_list)))
except ValueError:
print("Please enter a number.")
else:
if index:
spot = int(index) - 1
for item in new_list:
shopping_list.insert(spot, item.strip())
spot += 1
else:
for item in new_list:
shopping_list.append(item.strip())
Gary Gibson
5,011 PointsGary Gibson
5,011 PointsI know, but my use of it is not doing what I want
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsBrendan Whiting
Front End Web Development Techdegree Graduate 84,735 PointsWhere are you using it? I don't see.