I am trying to get values from a shelve db but it keeps failing

Question

SamarthWiz 0 Newbie Poster

15 Years Ago

Hi I am trying open a record from a shelve db I Know that it stops working at copy = db[opened]

But why please help ASAP

#*****START VARIABEL BLOCK*****
#file = the database/shelf file
#db = the database/shelf object 
#tapp = to be appended/recorded to the database
#keys = a list of all the database's keys
#flag = if True = that record/rey already exists, if False = that record/rey does not exist
#Name = 1st field
#note = 2nd field
#strkey=str(key)
#*****END VARIABEL BLOCK*****

def on_OpenKey_command(self, event):

    try:
        global db

        opened = str(self.components.key.text)

        copy = db[opened]
        tapp = []
        tapp = easygui.multenterbox(msg = "Edit the properties,then press Ok to save.", title = "DataBank|Edit", fields = ("KEY","1","2","3","4","5","6","7","8","10"), values = copy)
        tapp = copy
        KEY = tapp[0]
        KEY = str(KEY)

        db[KEY] = tapp
        self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
        self.components.dbItems.items = Items


        Items = db.values()

        self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
        self.components.dbItems.items = Items

    except: 


        global db
        tapp = []
        tapp = easygui.multenterbox("Edit the properties,then press Ok to save.","DataBank|Edit", ("KEY","1","2","3","4","5","6","7","8","10"))
        key  = tapp[0]
        keys = str(key)
        db[keys] = tapp
        Items = str(db.values())

        Items = db.values()

        self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
        self.components.dbItems.items = Items

python

Edited 13 Years Ago by Member #120589 because: fixed formatting

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Latest Post 15 Years Ago Latest Post by SamarthWiz

Dani AI

Generated 9 Months Ago

A few focused checks and small fixes will make the failure at the point where you do the lookup much easier to diagnose and eliminate.

Quick checklist (do these first)

Print a full traceback instead of using a bare except so you see the real exception (KeyError, NameError, TypeError, etc.).
Print the shelf and key right before the lookup: the type of db, repr(key), and list(db.keys()) (or list(db)), to confirm the key really exists and is the expected string.
Guard the lookup so it does not raise unexpectedly (use membership test or get) and handle GUI cancel returns (multenterbox can return None).

Minimal safe patterns

import traceback

key = str(self.components.key.text).strip()
try:
    if key not in db:
        easygui.msgbox("No record found for {!r}".format(key))
    else:
        record = db[key]
except KeyError:
    easygui.msgbox("Key error for {!r}".format(key))
except Exception:
    traceback.print_exc()
    raise

Or use record = db.get(key) and check for None before using it.

Other likely causes and fixes

Uninitialized/closed db: the intermittent success you mentioned () looks like a race where db is not reliably opened. Make db an attribute (e.g., self.db) and ensure you open it before any UI action.
Keys: shelve keys must be strings; trim whitespace and use repr() when debugging to reveal hidden characters.
GUI cancel: easygui.multenterbox can return None — treat that case before assigning or writing back.
Avoid writeback=True unless needed (it masks in-place changes and uses memory).
Replace repeated UI-update blocks with one refresh_items() helper that reads list(self.db.values()) and updates the grid.

Follow advice: add prints/tests around the failing line, capture the traceback, and then post the traceback if you still need help. These steps will show whether the problem is a missing key, an un-opened shelf, a bad key string, or a concurrency/locking issue.

All 4 Replies

Gribouillis 1,391 Programming Explorer

15 Years Ago

If it stops working, there must be a traceback or something. Can you post the traceback ? Also your code doesn't show what is db nor its content, perhaps you could attach the shelve file in a zipped form. The 'global db' statements are suspicious. At best, they serve no purpose.

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SamarthWiz 0 Newbie Poster · Answer 1 · 2011-09-04T14:41:56+00:00

here is the full code:

#!/python-32
# -*- coding: utf-8 -*-
# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is data-bank.
#
# The Initial Developer of the Original Code is
# Samarth Agarwal.
# Portions created by the Initial Developer are Copyright (C) 2011
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
#
#***** END LICENSE BLOCK *****
#
#*****START VARIABEL BLOCK*****
#file = the database/shelf file
#db = the database/shelf object 
#tapp = to be appended/recorded to the database
#keys = a list of all the database's keys
#flag = if True = that record/rey already exists, if False = that record/rey does not exist
#Name = 1st field
#note = 2nd field
#strkey=str(key)
#*****END VARIABEL BLOCK*****



#******Imports all the modules it needs(V)*****
import shelve
from PythonCard import model
import easygui
import os
#******Imports all the modules it needs(^)*****
Version = 2.0
#


#***********The main program(V)****************************************************************************************3        
class MainWindow(model.Background):
    #self.components.del.visible = False
    #self.components.del.enabled = False 
    
    def on_About_command(self, event):
        global db
        try:
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
        except:
            pass

        About = open("README.txt", "r")
        easygui.textbox(msg="About DataBank\nVersion %i \nCopyright 2011 Samarth Agarwal" % Version, title="DataBank|About", text=About)
        About.close()
    def on_License_command(self, event):
        global db
        try:
            Items = db.values()
            
            self.components.dbItems.columnHeadings = self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
        except:
            pass
        License = open("License.txt", "r")
        easygui.textbox(msg="About DataBank\nVersion %i \nCopyright 2011 Samarth Agarwal" % Version, title="DataBank|About", text=License)
        License.close()
        
        
#***********Creates a new db/opens db/Saves DB(V)*************  
    
    def on_Newdb_command(self, event):
        global db
        
        try:
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
        except:
            pass
        file = easygui.filesavebox(msg = "Where do you want to save your database??",  title = "DATABANK|NewDb", default = "*.dat", filetypes = ["*.dat"] )
        try:
            db = shelve.open(file, writeback=True)
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
          
        except:
            pass
        
    def on_Opendb_command(self, event):
        global db
        
        
        try:
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
            
        except:
            pass
        file = easygui.fileopenbox(msg = "What database do you want to open??",  title = "DATABANK|OpenDB", default = "*.dat", filetypes = ["*.dat"] )
        try:
            db = shelve.open(file, writeback=True)
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
            
        except:
            pass
        
    
    
    
    def on_Savedb_command(self, event):
        global db
        
        try:
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
        except:
            pass
        try:
            db.sync()
            easygui.msgbox(msg="Sync Sucssful",  title="Sync|DataBank")
                    
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items
            
        except:
            easygui.exceptionbox(msg="An ERROR occurred ,if this error continues to occurred then file a issue on: http://code.google.com/p/data-bank/ and reproduce the error message below:", title="ERROR|DataBank")
     

    
            
    
        


#***********Creates a new db/opens db(^)*************    


#******************Saves A record/Opens a recored/Creates a record(V)    



 


    
    def on_OpenKey_command(self, event):
        
        try:
            global db
            
            opened = self.components.key.text
            openedstr = str(opened)
            copy = db[opened]
            tapp = []
            tapp = easygui.multenterbox(msg = "Edit the properties,then press Ok to save.", title = "DataBank|Edit", fields = ("KEY","1","2","3","4","5","6","7","8","10"), values = copy)
            tapp = copy
            KEY = tapp[0]
            KEY = str(KEY)

            db[KEY] = tapp
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items

           
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items

        except: 
            
            
            global db
            tapp = []
            tapp = easygui.multenterbox("Edit the properties,then press Ok to save.","DataBank|Edit", ("KEY","1","2","3","4","5","6","7","8","10"))
            key  = tapp[0]
            keys = str(key)
            db[keys] = tapp
            Items = str(db.values())
            
            Items = db.values()
            
            self.components.dbItems.columnHeadings = [['KEY'], ['1'], ['2'], ['3'], ['4'], ['5'], ['6'], ['7'], ['8'], ['9'], ['10'],['11']]
            self.components.dbItems.items = Items

            
            

     
    

#******************Saves A record/Opens a recored/Creates a record(^)
    
#******The main program(^)*********************************************************************************************3

app = model.Application(MainWindow) #The apps instance
try:
    app.MainLoop() #the main loop
except:
    easygui.exceptionbox(msg="An ERROR occurred ,if this error continues to occurred then file a issue on: http://code.google.com/p/data-bank/ and reproduce the error message below:", title="ERROR|DataBank")

Gribouillis 1,391 Programming Explorer Team Colleague · Answer 2 · 2011-09-04T16:57:31+00:00

Well, if the error is at line 178, you could perhaps add tests before that line: check that db is a Shelf, check that it has the key 'opened', print the key and whole content of the shelf, etc. Also print a message after line 178 to see if the program reaches this point, etc.

Your program contains many repeated blocks, like line 58-61. Write a function to execute these 3 lines and call this function instead of repeating the lines of code. Also a global db is not a good idea, why not have a member ?

SamarthWiz 0 Newbie Poster · Answer 3 · 2011-09-04T18:04:25+00:00

I have tried Printing 1,2,3 etc after every line thats how I got to the point of line 178 being the problem but for some reason after a few fails It works properly

I am trying to get values from a shelve db but it keeps failing

Dani AI

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