[Tutor] Why doesn't it save the data before exiting? CORRECTION
Nathan Pinno
falcon3166 at hotmail.com
Tue Jun 27 03:22:07 CEST 2006
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
>
>
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