[Tutor] Why doesn't it save the data before exiting? CORRECTION

[Nathan Pinno]

Would it be this line?

pickle.dump(ac, store)

Would this make it work?

ac = pickle.dump(store)

Nathan
----- Original Message ----- 
From: "Bob Gailer" <bgailer at alum.rpi.edu>
To: "Nathan Pinno" <falcon3166 at hotmail.com>
Cc: <tutor at python.org>
Sent: Monday, June 26, 2006 5:33 PM
Subject: Re: [Tutor] Why doesn't it save the data before exiting? CORRECTION


> Nathan Pinno wrote:
>> How do I know? Simple. Next time I load it and ask it to print the list 
>> of accounts and how much in each, I only get:
>>
>> Account Info
>>
>> then the menu again, with no info.
> Ah. But the program starts setting accountlist = {}. When you reach 
> printall, accountlist is still {}. Can you figure out why?
>
> Hint: load_file(accountlist) does not change accountlist.
>>
>> Nathan Pinno
>> ----- Original Message ----- From: "Bob Gailer" <bgailer at alum.rpi.edu>
>> To: "Bob Gailer" <bgailer at alum.rpi.edu>
>> Cc: "Nathan Pinno" <falcon3166 at hotmail.com>; <tutor at python.org>
>> Sent: Monday, June 26, 2006 5:19 PM
>> Subject: Re: [Tutor] Why doesn't it save the data before exiting? 
>> CORRECTION
>>
>>
>>> Bob Gailer wrote:
>>>> Nathan Pinno wrote:
>>>>
>>>>> Hey all,
>>>>>  I am needing help on this. Why isn't it saving the data beore exiting 
>>>>> the program?
>>>>>
>>>> But it does save it. What evidence do you have that it is not?
>>>>
>>>> Please in the future always tell us what the evidence of a problem is.
>>>>
>>>> Also I suggest you add validation of user input, to avoid the program 
>>>> terminating if the user hits the wrong key. In fact the whole menu 
>>>> thing would be easier to manage if the choices were character rather 
>>>> than integer. Then you don't need int() conversion and the exception 
>>>> raising if the user does not enter an integer string.
>>>>
>>>> Similar comment regarding checking input before applying float().
>>>>
>>>> Consider % formatting for the outputs as in:
>>>>         print "%s\t $%2f\n" % (account, accountlist[account]) # instead 
>>>> of
>>>>         print account+"\t $"+str(accountlist[account]),"\n"
>>>>
>>>> Also I suggest you not open store for writing until just before the 
>>>> pickle.dump. Otherwise it is possible to have an empty file on which 
>>>> pickle.load will raise an exception.
>>>>
>>>>> I don't get an error before exiting.
>>>>>
>>>> Good. You should not, unless you enter something that won't convert to 
>>>> integer, or string [ I MEANT float ], or you leave an empty account.txt 
>>>> file.
>>>>
>>>>>  Here's the code so far:
>>>>> accountlist = {}
>>>>>  def load_file(ac):
>>>>>     import os
>>>>>     import pickle
>>>>>     filename = 'accounts.txt'
>>>>>     if os.path.exists(filename):
>>>>>         store = open(filename, 'r')
>>>>>         ac = pickle.load(store)
>>>>>     else:
>>>>>         store = open(filename, 'w')
>>>>>     store.close()
>>>>>    def save_file(ac):
>>>>>     import pickle
>>>>>     store = open('accounts.txt', 'w')
>>>>>     pickle.dump(ac, store)
>>>>>     store.close()
>>>>>  def main_menu():
>>>>>     print "1) Add a new account"
>>>>>     print "2) Remove a account"
>>>>>     print "3) Print all info"
>>>>>     print "4) Find account"
>>>>>     print "5) Deposit"
>>>>>     print "6) Withdraw funds"
>>>>>     print "9) Save and exit."
>>>>>  def add():
>>>>>     print "Add a new account"
>>>>>     account = raw_input("Account Name: ")
>>>>>     amount = float(raw_input("Amount: "))
>>>>>     accountlist[account] = amount
>>>>>  def remove():
>>>>>     print "Remove a account"
>>>>>     account = raw_input("Account: ")
>>>>>     if accountlist.has_key(account):
>>>>>         del accountlist[account]
>>>>>     else:
>>>>>         print account," was not found."
>>>>>  def printall():
>>>>>     print "Account Info"
>>>>>     for account in accountlist.keys():
>>>>>         print account+"\t $"+str(accountlist[account]),"\n"
>>>>>  def lookup():
>>>>>     print "Specific Account Info"
>>>>>     account = raw_input("Account: ")
>>>>>     if accountlist.has_key(account):
>>>>>         print account+"\t $"+str(accountlist[account]),"\n"
>>>>>     else:
>>>>>         print account," was not found."
>>>>>  def deposit():
>>>>>     print "Deposit funds"
>>>>>     account = raw_input("Account: ")
>>>>>     if accountlist.has_key(account):
>>>>>         amount = float(raw_input("Amount: "))
>>>>>         accountlist[account] += amount
>>>>>         print account+"\t $"+str(accountlist[account]),"\n"
>>>>>     else:
>>>>>         print account," was not found."
>>>>>  def withdraw():
>>>>>     print "Withdraw Funds."
>>>>>     account = raw_input("Account: ")
>>>>>     if accountlist.has_key(account):
>>>>>         amount = float(raw_input("Amount: "))
>>>>>         accountlist[account] -= amount
>>>>>         print account+"\t $"+str(accountlist[account]),"\n"
>>>>>     else:
>>>>>         print account," was not found."
>>>>>  print "Account Tracker"
>>>>> print "By Nathan Pinno"
>>>>> print
>>>>> load_file(accountlist)
>>>>> while 1:
>>>>>     main_menu()
>>>>>     menu_choice = int(raw_input("Which item? "))
>>>>>     if menu_choice == 1:
>>>>>         add()
>>>>>     elif menu_choice == 2:
>>>>>         remove()
>>>>>     elif menu_choice == 3:
>>>>>         printall()
>>>>>     elif menu_choice == 4:
>>>>>         lookup()
>>>>>     elif menu_choice == 5:
>>>>>         deposit()
>>>>>     elif menu_choice == 6:
>>>>>         withdraw()
>>>>>     elif menu_choice == 9:
>>>>>         break
>>>>>     else:
>>>>>         print "That's not an option. Please choose a valid option."
>>>>> save_file(accountlist)
>>>>> print "Have a nice day!"
>>>>>  Thanks for the help so far!
>>>>> Nathan Pinno
>>>>> ------------------------------------------------------------
>>>
>>
>
>
> -- 
> Bob Gailer
> 510-978-4454
>
>