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User input not saving into inventory list

Basically I am making an app to better assist me at managing my ebay store. I am still very new to programming and OOP. After watching some tutorials I pieced together the following code. Everything so far works pretty well. What I am currently stuck on is when the user inputs an item for inventory, it is not saving it. And, when the user wants to view the inventory the item they added wont populate. Any input or suggestions would be much apprenticed.
def Inventory():
All_Inventory = {}
class Ebay_Inventory:
def __init__(self, manufacturer, object_type, price):
self.manufacturer = manufacturer
self.object_type = object_type
self.price = price
def add_item(self):
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item_info = Ebay_Inventory(manufacturer, object_type, price)
All_Inventory = item_info
print("Item added successfully")
def delete_item(self):
delete = input("What is the item you want to delete?: ")
if delete in All_Inventory.keys():
del[delete]
print("The item entered has been deleted.")
else:
print("Item not found")
def sale_status(self):
update = input("What is the item you want to update?:")
if update in All_Inventory.keys():
pass
else:
print("Item not found")
user=True
while user:
print("\n1. Add to item inventory")
print("2. Remove item from inventory")
print("3. Update sale status")
print("4. View inventory")
print("5. Exit program")
user_wants=input("What would you like to do today?")
if user_wants=="1":
Ebay_Inventory.add_item(input)
elif user_wants=="2":
Ebay_Inventory.delete_item(input)
elif user_wants=="3":
Ebay_Inventory.sale_status(input)
elif user_wants=="4":
print(All_Inventory)
elif user_wants=="5":
print("\n Thank you for using item inventory.")
break
elif user_wants!="":
print("\n Input not understood. Please try again.")

You need to read about Scope, OOP and dicts:
You are not adding to your Inventory.All_Inventory - you create a new local with All_Inventory = item_info
https://docs.python.org/3/tutorial/classes.html#python-scopes-and-namespaces
Short description of the scoping rules?
You mix up static class attributes and instance attributes, read:
https://docs.python.org/3/tutorial/classes.html#class-objects.
What is the difference between #staticmethod and #classmethod?
You are deleting / accessing your dictionary wrongly - see :
https://docs.python.org/3/tutorial/datastructures.html#dictionaries
Delete an element from a dictionary
Fixed:
class Ebay_Inventory:
Inventory = {} # class property
#staticmethod
def print_inventory():
for k in Ebay_Inventory.Inventory:
for i in Ebay_Inventory.Inventory[k]:
print(k,i)
class Ebay_Item:
def __init__(self, key, manufacturer, object_type, price):
self.manufacturer = manufacturer
self.object_type = object_type
self.price = price
self.key = key
def __str__(self):
return f"{self.manufacturer} {self.object_type} {self.price}"
def __repr__(self):
return str(self)
#staticmethod
def add_item(key=None, man=None, obj=None, pri=None):
# use values if given, else ask - this is for demo purposes only
key = key or input("Enter key: ")
manufacturer = man or input("Enter Manufacturer: ")
object_type = obj or input("Enter what the item is: ")
price = pri or input("Enter price: ")
# create new item
item_info = Ebay_Inventory.Ebay_Item(key, manufacturer, object_type, price)
# add to class member, create key if need be
Ebay_Inventory.Inventory.setdefault(item_info.key,[]).append(item_info)
def delete_item(key=None):
delete = key or input("What is the item you want to delete?: ")
if delete in Ebay_Inventory.Inventory:
del Ebay_Inventory.Inventory[delete]
print("The item entered has been deleted.")
else:
print("Item not found")
def __str__(self):
return Ebay_Inventory.print_inventory()
# add 2 items and print
Ebay_Inventory.add_item(1,"Me","Me",1000)
Ebay_Inventory.add_item(2,"You","You",1000)
Ebay_Inventory.print_inventory()
# remove non existent and existent item and print
Ebay_Inventory.delete_item(3)
Ebay_Inventory.delete_item(2)
Ebay_Inventory.print_inventory()
Output:
1 Me Me 1000
2 You You 1000
Item not found
The item entered has been deleted.
1 Me Me 1000

Sorry to rework your code pretty extensively, but I think this is more like what you are going for:
class EbayInventory:
def __init__(self):
self.all_inventory = []
def print_items(self):
print('Current item list by index:')
for i in range(0, len(self.all_inventory)):
print("{} -> {}".format(i+1, self.all_inventory[i]))
def add_item(self):
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item = {'manufacturer': manufacturer, 'type': object_type, 'price': price}
self.all_inventory.append(item)
print("Item added successfully")
def delete_item(self):
self.print_items()
delete = int(input("Item id you want to delete: "))
try:
del self.all_inventory[delete - 1]
print("The item entered has been deleted.")
except Exception as e:
print("An error occurred deleting that item, details below")
print(e)
def sale_status(self):
self.print_items()
update_index = int(input("Item id you want to update: "))
if update_index > len(self.all_inventory) or update_index <= 0:
print("You're trying to change an item that doesn't exist!!")
return
print("OK. Let's get that item up to date!")
manufacturer = input("Enter Manufacturer: ")
object_type = input("Enter what the item is: ")
price = input("Enter price: ")
item = {'manufacturer': manufacturer, 'type': object_type, 'price': price}
self.all_inventory[update_index - 1] = item
print("OK. We got that update taken care of")
if __name__ == "__main__":
my_app = EbayInventory()
while True:
print("\n1. Add to item inventory")
print("2. Remove item from inventory")
print("3. Update sale status")
print("4. View inventory")
print("5. Exit program")
user_wants = input("Please enter the number corresponding to how you would like help: ")
if user_wants == "1":
my_app.add_item()
elif user_wants == "2":
my_app.delete_item()
elif user_wants == "3":
my_app.sale_status()
elif user_wants == "4":
my_app.print_items()
elif user_wants == "5":
print("Thank you for using item inventory.")
break
else:
print("Input not understood. Please try again.")
You had a variable user that did nothing. You can simply enter an infinite loop with while True:. If you wanted to loop the way you did, then instead of a break you could have put a user = False to break out of the loop. This is sometimes a nifty trick, but doesn't make sense here I think. It seemed to me the inventory was really the only thing that would benefit by being stored in your class, and the methods could then access it to adjust it via a self.all_inventory. I moved your code to ask for item inputs to the add_item() and sale_status() methods, so now the main block of code looks a lot cleaner. I also wrapped it in if __name__ == "__main__": so that you can import this class to another project without running the entire program! I threw in some basic error checking with try: and except: clauses also. I think you were misunderstanding the difference between a Class and an Instance. So in my code the Class is EbayInventory, but the Instance is my_app. You create instances of your class just like I did with my_app = EbayInventory() and then the self now refers to my_app. In this manner I can call my_app.add_item(). You can have several instances of objects though, and they each have their own space in your computers memory. So you could have said:
app1 = EbayInventory()
app2 = EbayInventory()
app1.add_item()
And only the app1 will have any items, whereas app2 is still an empty list, but still has the methods to build an inventory via app2.add_item(). To answer your main question though, you never call your function Inventory() and therefore it doesn't exist to hold your information. When you call item_info = Ebay_Inventory(manufacturer, object_type, price) in fact you are making an Instance of a class, which is really nonsensical to do here because that means on the next line you could say item_info.add_item() and this would make another instance, yet you are not saving this information anywhere so you can never retrieve it!

Updating a list in a Python class

I want to update a list to include new items added by a user. There are a few conditions such as the code must be 7 digits long. If the code already exists, the system will notify the user. If the user tries to add another copy of 'up' with a different code, the system will not allow it. It will make them try again as the code must be the same. Eventually I will include a video number, so if there are two copies of 'up' they will have two different video numbers but the same video code.
Can someone show me why the following code is not working for me?
all_movies = []
class Movie(object):
movie_list = []
def __init__(self, code, title, director):
self.code = code
self.title = title
self.director = director
Movie.movie_list.append(self)
#staticmethod
def add_movie():
mv_code = input("Code of movie: ")
movie_code = int(mv_code)
movie_title = input("Name of movie: ")
movie_director = input("Director: ")
if len(mv_code) == 7:
all_movies.append(Movie(movie_code, movie_title, movie_director))
print("movie added to database")
else:
print("the code must be 7 digits long, add movie again.")
def check_validity(movie_code, all_movies):
if movie_code in all_movies:
return True
else:
return False
if check_validity(movie_code, all_movies):
all_movies[all_movies] += Movie
print()
print("updated")
else:
all_movies[movie_code] = [movie_code, movie_title, movie_director]
def main():
movie1 = Movie(1122334, 'Up', 'Director')
movie2 = Movie(1231235, 'Taxi Driver', 'Film-maker')
This is the error message that I am receiving:
all_movies[movie_code] = [movie_code, movie_title, movie_director]
IndexError: list assignment index out of range

First of all this structure is not suitable for your desires.
About the error you got, I should say that you have to define you all movies as a dictionary not a list (because of the that you want to use for each movie).
try this:
all_movies = {}
in you add_movie method:
#staticmethod
def add_movie():
mv_code = input("Code of movie: ")
movie_code = int(mv_code)
movie_title = input("Name of movie: ")
movie_director = input("Director: ")
if len(mv_code) == 7:
if movie_code in all_movies.keys():
print("the movie already exists")
# what do you want to happen here ?
else:
all_movies[movie_code] = (movie_code, movie_title, movie_director)
print("movie added to database")
else:
print("the code must be 7 digits long, add movie again.")
This will add a movie to the all_movies and you don't need the rest your code, and i didn't understand the usage of init and movie_list.
Try this, then tell me what happens if the code already exists in the movies, I will update my answer for you.
UPDATE:
According to your desires in comment the method will updated to something like this:
#staticmethod
def add_movie():
mv_code = input("Code of movie: ")
movie_code = int(mv_code)
movie_title = input("Name of movie: ")
movie_director = input("Director: ")
if len(mv_code) == 7:
if movie_code in all_movies.keys():
print("the movie is already exists, adding it with another video number")
# all_movies[movie_code][-1] is the last video with an existing key
# all_movies[movie_code][-1][-1] last video number generated
new_video_number = all_movies[movie_code][-1][-1] + 1
all_movies[movie_code].append([movie_title, movie_director, new_video_number]) # adding it with new video number
print("movie added to database with new video number")
else:
all_movies[movie_code] = []
all_movies[movie_code].append([movie_title, movie_director, 1]) # 1 is the first movie added(video number)
print("movie added to database")
else:
print("the code must be 7 digits long, add movie again.")
This will returns all_movies like this:
{
'1231235':[
['Taxi Driver', 'Film-maker', 1]
]
'1122334':[
['Up', 'Director',1],
['Up', 'Director',2],
['Up', 'Director',3],
]
'1122333':[
['Another movie', 'Another Director',1],
['Another movie', 'Another Director',2],
]
}
The last element of inner list are the video_numbers that generated automatically by system.

Tying values to keys in a dictionary and then printing

This is a smaller portion of the main code I have been writing. Depending on user selection they can add player informationa and then print the information from the dictionary player roster. I want to store the information and then print in this format but I havent been able to figure out how to do this.
Name ****
Phone Number ****
Jersey Number ****
Im new to dictionaries but I have spent hours reading and searching over the past couple of days about dictionaries and have tried several different ways to do this but failed. I have gotten the closest the way I have it setup now but it still doesnt work right. I feel like I am storing the information incorrectly into the dictionary for starters, any help would be greatly appreciated.
player_roster = {}
def display_roster(self): #Print Roster
if len(player_roster) != 0:
for x in player_roster.keys():
print('Name:', x, 'Phone Number:', player_roster[x])
else: #Print No One on Roster
len(player_roster) == []
print('No names have been entered:')
def add_player(self,): #Enter Members Name
name = input('Enter New Players Name:')
phone_number = input('Enter Players Phone Number:')
jersey_number = int(input('Enter Players Jersey Number'))
player_roster[name] = phone_number, 'Jersey Number', jersey_number
#If I input Toby as Name 444-444 as Phone Number and 3 as Jersey number it outputs like this
Name: Toby Phone Number: ('444-4444', 'Jersey Number', 3)
# I would like it to output like
Name: Toby
Phone Number: 444-4444
Jersey Number: 3

There are some things i would change in your code but to keep this close to what you asked for take a look at this:
def display_roster():
if len(player_roster) != 0:
for x in player_roster.keys():
print('Name:', x)
print('Phone Number:', player_roster[x][0])
print('Jersey Number:', player_roster[x][1])
else:
print('Roster is empty.')
return
player_roster = {}
def add_player():
name = input('Enter New Players Name:\t')
phone_number = input('Enter Players Phone Number:\t')
jersey_number = int(input('Enter Players Jersey Number:\t'))
player_roster[name] = [phone_number, jersey_number]
return
add_player()
display_roster()
# PRINTS:
#Name: Toby
#Phone Number: 444-4444
#Jersey Number: 3
Printing in multiple lines gives you the result you want. As stated in the comments this can also be done with a single print() statement but i do not think compact code makes much difference to you yet.
Further, this len(self.player_roster) == [] line does not make sense. This is as good as simply writing True in a line. The "emptiness" of the team is checked by the else:.
Finally, i would slightly change the way players are stored in the "Roster" dictionary and have it like this: {"Toby": ['444-4444', 3], ...}

I would propose that you replace the print statement to this:
print(" Name: %s \n Phone Number: %s \n Jersey Number: %d") % player_roster[x]

You're pretty much there. The below modification would allow you to print as you need (and is slightly more readable):
class PlayerDictionary():
def __init__(self):
pass
player_roster = {}
def display_roster(self): #Print Roster
if len(self.player_roster) != 0:
for key, value in self.player_roster.iteritems():
print(str(key) + ": " + str(value))
else: #Print No One on Roster
len(self.player_roster) == []
print('No names have been entered:')
def add_player(self,):
self.player_roster['Name'] = input('Enter New Players Name:')
self.player_roster['Phone Number'] = input('Enter Players Phone Number:')
self.player_roster['Jersey Number'] = int(input('Enter Players Jersey Number'))
if __name__ == "__main__":
player = PlayerDictionary()
player.add_player()
player.display_roster()
A slightly more maintainable solution would be to create a class for Player. Set the properties on the object and overload the str function e.g.
class Player(object):
def __init__(self):
self.__name = ""
self.__phone_number = ""
self.__jersey_number = ""
#property
def name(self):
return self.__name
#property
def phone_number(self):
return self.__phone_number
#property
def jersey_number(self):
return self.__jersey_number
#name.setter
def name(self, val):
self.__name = val
#phone_number.setter
def phone_number(self, val):
self.__phone_number = val
#jersey_number.setter
def jersey_number(self, val):
self.__jersey_number = val
def __str__(self):
return ("Name: %s\nPhone Number: %s\nJersey Number: %s" % (str(self.__name), str(self.__phone_number), str(self.__jersey_number)))
if __name__ == "__main__":
player = Player()
player.name = input('Enter New Players Name:')
player.phone_number = input('Enter Players Phone Number:')
player.jersey_number = int(input('Enter Players Jersey Number'))
print(player)

How do I access the array using the for loop in the while loop

I am working with an external file which has data in the form of:
-12345 CSEE 35000 Bart Simpson
-12346 CSEE 25000 Harry Potter
-12350 Economics 30000 Krusty The Clown
-13123 Economics 55000 David Cameron
With the first item being the ID, the second the subject, the third the salary, and the rest being the name of the person.
In part of my program I am trying to print the information of the people who have salaries between values submitted by the user. I have put all the data in a list called lecturers then I put all the salaries in a separate list called lecturers salary and tried to make them integers because at first I thought the reason the for loop wasn't working was because when trying to access them from the lectures loop I thought they might still be part of a string at this point.
I have already used a loop in my program to print all the people who teach a specific subject. This subject is submitted by the user. I tried to use a for loop again for the salaries but its not working.
print""
# To God be the Glory
lecturer = []
lecturer_salary = []
x = 0
a = " "
print ""
String = raw_input("Please enter the lecturers details: ")
print ""
def printFormat(String):
String = String.split()
lastname = String[-1]
firstnames = " ".join(String[3:-1])
name = ", ".join([lastname, firstnames])
ID_Subject = " ".join(String[0:2])
money = String[2]
print "%s,%s %s %s" % (lastname,firstnames,ID_Subject,money)
printFormat(String)
while x < len(lecturer):
lecturer_salary.append(int(lecturer [x][2]))
x = x + 1
print ""
try:
fname = input("Enter filename within " ": ")
with open(fname) as f:
for line in f:
data = line.split()
printFormat(line)
line = line.split()
lecturer.append(line)
except IOError as e :
print("Problem opening file")
print ""
print ""
answer = raw_input("Would you like to display the details of lectureers from a particular department please enter YES or NO: ")
if answer == "YES" :
print ""
department = raw_input("Please enter the department: ")
print ""
while x < len(lecturer) :
for line in lecturer:
if lecturer[x][1] == department:
a = lecturer[x]
a = ' '.join(a)
printFormat(a)
x = x + 1
**elif answer == "NO" :
print ""
answer2 = raw_input ("Would you like to know all the lecturers within a particular salary range: ")
print ""
if answer2 == "YES":
lower_bound = int(input("Please enter the lower bound of the salary range: "))
upper_bound = int(input("Please enter the upper bound of the salary range: "))
print ""
while x < len(lecturer) :
for line in lecturer_salary:
if lower_bound < lecturer_salary[x] < upper_bound :
print lecturer_salary[x]
x = x + 1**
else:
print ""
print "Please enter a valid input"

So, you have an array of lecturer and one of lecturer salary. the
for line in lecturer_salary:
is not needed - just the while followed by the if. Note that this will only print out the salary, not the lecturer details. Since x is the index to both arrays you can access lecturer[x] for the rest. In truth you don't need the lecturer_salary at all, just walk through lecturer and check:
while x < len(lecturer) :
if lower_bound < lecturer[x][2] < upper_bound :
a = lecturer[x]
a = ' '.join(a)
printFormat(a)
x = x + 1

For starters, you shouldn't name your variable with a capital letter like String or Id_Subject.
It is simpler to break code into functions and try using a dictionary or class to improve readability and extensibility.
Here is a minimal code using class:
lecturers = [] # To store Lecturer instances, which isn't necessary
class Lecturer():
def __init__(self, id, subject, salary, name):
self.id = id
self.subject = subject
self.salary = salary
self.name = name
def readfile(filename):
"""read each line in a file and yield a list of fields"""
with open(filename, "r") as f:
for line in f.readlines():
# return a list of fields
yield line.replace("\n", "").split()
def new_lecturer(detail):
"""Return a new lecturer instance from a list of fields"""
return Lecturer(detail[0],
detail[1],
detail[2],
{"firstname": detail[3],
"lastname": detail[4]
})
def print_lecturer_detail(lecturer):
"""Accept a lecturer instance and print out information"""
print "{0},{1} {2} {3}".format(lecturer.name["lastname"],
lecturer.name["firstname"],
lecturer.id,
lecturer.salary)
def main():
"""This is where all the main user interaction should be"""
fname = raw_input("Enter filename: ")
for lecturer in (readfile(fname)):
lecturers.append(new_lecturer(lecturer))
print ""
answer = raw_input("Would you like to display lecturers by department(Y/N)?: ")
if answer == "Y":
print ""
department = raw_input("Please enter the department: ")
print ""
for lecturer in lecturers:
if lecturer.subject == department:
print_lecturer_detail(lecturer)
elif answer == "N":
# implement salary code here
pass
if __name__ == '__main__':
main()
This may be an overkill now, but it's better than dealing with lists in a long run. You'll see that dealing with properties become much simpler. You may want to improve each function further and make it more modular and reusable.
#Paul Morrington has the straight answer on the while part.

"None" given when attempting to return the value of dict in Python

I'm trying to return the values of a dict when creating an instance of a class in Python, but I keep getting "None" returned instead.
I'm very new to Python, so I'm sure there is an easy answer to this one.
After running the below:
class TestTwo(object):
def __init__(self):
self.attributes = {
'age': "",
'name' : "",
'location': ""
}
def your_age(self):
self.attributes['age'] = raw_input("What is your age? > ")
self.your_name()
def your_name(self):
self.attributes['name'] = raw_input("What is your name? > ")
self.your_location()
def your_location(self):
self.attributes['location'] = raw_input("Where do you live? > ")
self.results()
def results(self):
print "You live in %s" % self.attributes['location']
print "Your number is %s" % self.attributes['age']
print "Your name is %s" % self.attributes['name']
d = self.attributes
return d
output = TestTwo().your_age()
print output
I end up with this:
MacBook-Pro-2:python johnrougeux$ python class_test.py
What is your age? > 30
What is your name? > John
Where do you live? > KY
You live in KY
Your number is 30
Your name is John
None
Instead of "None", I was expecting "{'age': '30', 'name': 'John', 'location': 'KY'}"
What am I missing?

Only results() returns something. You need to pass its return value along the call chain by returning it in the other functions if you want them to return something, too:
def your_age(self):
self.attributes['age'] = raw_input("What is your age? > ")
return self.your_name()
def your_name(self):
self.attributes['name'] = raw_input("What is your name? > ")
return self.your_location()
def your_location(self):
self.attributes['location'] = raw_input("Where do you live? > ")
return self.results()
Of course this kind of chaining is extremely ugly; but I'm sure you already know that. If not, rewrite your code like this:
in each of those functions, just set the value and do not call one of your other functions. Then add a function such as this:
def prompt_data(self):
self.your_age()
self.your_name()
self.your_location()
In the code using the class, do this:
t2 = TestTwo()
t2.prompt_data()
output = t2.results()

the function your_age() doesn't return any values, of course output is None