This script takes user input (for employee) and adds via SQLAlchemy to a sqlite3 .db. It worked fine until I added try: except clause(s) in the add_data method for the age field (planning on adding more try/except clauses to the other fields). The age field needs to be an int chosen by the user. I realized I needed a way to catch any errors caused by the user adding a string to the field instead of a number. The relevant code. . .
try:
self.age = self.age_var.get()
except ValueError:
showinfo("Error:", "Please Enter A Number In Age Field.")
However when I do this, it creates a problem because age now becomes a local variable (as Backtrack pointed out in another post) and I get the UnboundLocalError: local variable 'age' referenced before assignment. I tried changing the code by separating the retrieving of the data and adding to the database, like this. . .
def get_data(self):
self.name = self.name_var.get()
try:
self.age = self.age_var.get()
except ValueError:
showinfo("Error:", "Please Enter A Number In Age Field.")
self.addr = self.address_var.get()
self.city = self.city_var.get()
self.state = self.state_var.get()
self.zip = self.zip_var.get()
self.ssn = self.ssn_var.get()
self.phone = self.phone_var.get()
self.cell = self.cell_var.get()
def add_data(self):
self.get_data()
# create new Employee in .db
new_person = Employee(name=self.name, age=self.age, address=self.addr, city=self.city, state=self.state, zip=self.zip, ssn=self.ssn, phone=self.phone, cell=self.cell)
session.add(new_person)
session.commit()
session.close()
self.callback()
return
However, I have the same problem in a different guise. Now I get AttributeError: GUI instance has no attribute 'age'. I'm not sure how to get around these problems. I tried adding a default value to age before the try/except clause self.age=0 which does correct the error, but creates another problem. .if a user enters a string instead of an int, the showinfo box appears with the warning, but when the user clicks 'ok', the default value '0' is automatically added to the database instead of giving the user another chance to enter a number for the age. Of course I could just change the age field to a String in Class Employee, but this isn't what I want. I'm lost as what to do. Any help is greatly appreciated! Anyway, here's the original code. . .
from datetime import datetime
from Tkinter import *
from tkMessageBox import *
import sqlite3, sqlalchemy
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, DateTime, Integer, String, MetaData
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
# map classes to tables through Base Class
Base = declarative_base()
class Employee(Base):
__tablename__ = 'employee'
id = Column(Integer, primary_key=True)
name = Column(String(250))
age = Column(Integer)
address = Column(String(250))
city = Column(String(10))
state = Column(String(2))
zip = Column(Integer)
ssn = Column(String(12))
phone = Column(String(12))
cell = Column(String(12))
# create engine for Session connection
engine = create_engine('sqlite:///employee.db')
# create all tables in engine ('CREATE TABLE' in raw SQL)
Base.metadata.create_all(engine)
# create configured 'Session' class
Session = sessionmaker(bind=engine)
# create session
session = Session()
class GUI:
def __init__(self, parent):
self.parent = parent
# create top frame
frame = Frame(parent)
frame.pack(expand=YES, fill=BOTH, padx=5, pady=5)
# create bottom frame
btm_frame = Frame(parent, relief=SUNKEN, borderwidth=1)
btm_frame.pack(side=BOTTOM, expand=YES, fill=BOTH, padx=5, pady=5)
# create datetime object
d = datetime.today()
date = d.strftime("%Y-%m-%d")
#------------------------Create Labels-------------------------------#
# label to display date
date_label = Label(btm_frame, text=date)
date_label.pack(side=LEFT)
# name label
name_label = Label(frame, text="Enter Name:")
name_label.grid(row=0, sticky=W)
# age label
age_label = Label(frame, text="Enter Age:")
age_label.grid(row=1, sticky=W)
# address label
addr_label = Label(frame, text="Enter Address:")
addr_label.grid(row=2, sticky=W)
# city label
city_label = Label(frame, text="Enter City:")
city_label.grid(row=3, sticky=W)
# state label
state_label = Label(frame, text="Enter State:")
state_label.grid(row=4, sticky=W)
# zip code label
zip_label = Label(frame, text="Enter Zip Code:")
zip_label.grid(row=5, sticky=W)
# ssn label
ssn_label = Label(frame, text="Enter Social Security #:")
ssn_label.grid(row=6, sticky=W)
# phone label
phone_label = Label(frame, text="Enter Phone #:")
phone_label.grid(row=7, sticky=W)
# cell label
cell_label = Label(frame, text="Enter Cell #:")
cell_label.grid(row=8, sticky=W)
#----------------------Create Vars and Entry-------------------------#
# name variable and entry
self.name_var = StringVar()
self.e1 = Entry(frame, textvariable=self.name_var)
self.e1.grid(row=0, column=1)
# age variable and entry
self.age_var = IntVar()
self.e2 = Entry(frame, textvariable=self.age_var)
self.e2.grid(row=1, column=1)
# address variable and entry
self.address_var = StringVar()
self.e3 = Entry(frame, textvariable=self.address_var)
self.e3.grid(row=2, column=1)
# city variable and entry
self.city_var = StringVar()
self.e4 = Entry(frame, textvariable=self.city_var)
self.e4.insert(0, "Roanoke") # insert default value
self.e4.grid(row=3, column=1)
# state variable and entry
self.state_var = StringVar()
self.e5 = Entry(frame, textvariable=self.state_var)
self.e5.insert(0, "VA") # insert default value
self.e5.grid(row=4, column=1)
# zip code variable and entry
self.zip_var = IntVar()
self.e6 = Entry(frame, textvariable=self.zip_var)
self.e6.grid(row=5, column=1)
# s.s.n variable and entry
self.ssn_var = StringVar()
self.e7 = Entry(frame, textvariable=self.ssn_var)
self.e7.grid(row=6, column=1)
# phone variable and entry
self.phone_var = StringVar()
self.e8 = Entry(frame, textvariable=self.phone_var)
self.e8.grid(row=7, column=1)
# cell variable and entry
self.cell_var = StringVar()
self.e9 = Entry(frame, textvariable=self.cell_var)
self.e9.grid(row=8, column=1)
# quit, search, clear, add, delete buttons
quit_button = Button(btm_frame, text="Quit", relief=GROOVE, command=parent.destroy)
quit_button.pack(side=RIGHT)
search_button = Button(btm_frame, text="Search", relief=GROOVE, command=self.search)
search_button.pack(side=RIGHT, padx=1, pady=1)
clear_button = Button(btm_frame, text="Clear", relief=GROOVE, command=self.clear_entries)
clear_button.pack(side=RIGHT, padx=1, pady=1)
del_button = Button(btm_frame, text="Delete", relief=GROOVE, command=self.del_employee)
del_button.pack(side=RIGHT, padx=1, pady=1)
add_button = Button(btm_frame, text="Add", relief=GROOVE, command=self.add_data)
add_button.pack(side=RIGHT, padx=1, pady=1)
def add_data(self):
name = self.name_var.get()
age = self.age_var.get()
addr = self.address_var.get()
city = self.city_var.get()
state = self.state_var.get()
zip = self.zip_var.get()
ssn = self.ssn_var.get()
phone = self.phone_var.get()
cell = self.cell_var.get()
# create new Employee in .db
new_person = Employee(name=name, age=age, address=addr, city=city, state=state, zip=zip, ssn=ssn, phone=phone, cell=cell)
session.add(new_person)
session.commit()
session.close()
self.callback()
return
def callback(self):
showinfo("New Employee", "Data Added")
self.clear_entries()
return
def clear_entries(self):
entries = [self.e1, self.e2, self.e3, self.e4, self.e5, self.e6, self.e7, self.e8, self.e9]
for entry in entries:
entry.delete(0, END)
return
def search(self):
search_win = Toplevel()
search_win.title("Employee Search")
# create labels for each employee attribute
attr = ["Id","Name","Age","Address","City","State","Zip","SSN","Cell","Phone"]
column = 0
for a in attr:
Label(search_win, text=a).grid(row=0,column=column,padx=2, pady=2)
column += 1
# search all employees, put each emp. in Entry Widget with For Loop
res = session.query(Employee).all()
row = 1
column = 0
for employee in res:
txt = [employee.id, employee.name, employee.age, employee.address, employee.city, employee.state, employee.zip, employee.ssn, employee.phone, employee.cell]
for t in txt:
ent = Entry(search_win, relief=RIDGE, width=19)
ent.grid(row=row, column=column, sticky=W, padx=1, pady=1)
ent.insert(0, t)
column += 1
row += 1
column = 0
return
def del_employee(self):
del_win = Toplevel()
del_win.title("Delete Employee")
id_label = Label(del_win, text="Enter Employee Id:")
id_label.grid(row=0, column=0, padx=5, pady=5)
self.employee_id = IntVar()
self.e10 = Entry(del_win, textvariable=self.employee_id)
self.e10.grid(row=0, column=1, padx=5, pady=5)
del_button = Button(del_win, text="Delete Employee", relief=GROOVE, command=self.erase)
del_button.grid(row=0, column=2, padx=5, pady=5)
return
def erase(self):
emp_id = self.employee_id.get()
res = session.query(Employee).filter(Employee.id==emp_id).first()
session.delete(res)
session.commit()
showinfo("Employee", "Data Deleted")
return
if __name__ == '__main__':
root = Tk()
root.geometry("310x270")
root.title("Employee Info")
mygui = GUI(root)
root.mainloop()
Here's the first error I got after changing the code above, adding the try: except clause to the age variable in the add_data method. . .In other words, change the add_data method above to this:
def add_data(self):
name = self.name_var.get()
try:
age = self.age_var.get()
except ValueError:
showinfo("Error:", "Please Enter A Number In Age Field.")
addr = self.address_var.get()
city = self.city_var.get()
state = self.state_var.get()
zip = self.zip_var.get()
ssn = self.ssn_var.get()
phone = self.phone_var.get()
cell = self.cell_var.get()
# create new Employee in .db
new_person = Employee(name=name, age=age, address=addr, city=city, state=state, zip=zip, ssn=ssn, phone=phone, cell=cell)
session.add(new_person)
session.commit()
session.close()
self.callback()
return
And I get this error when user inputs a string in the age field then clicking "ok" in the showinfo dialogue box):
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Python27\lib\lib-tk\Tkinter.py", line 1532, in __call__
return self.func(*args)
File "C:\Python27\test2_gui.py", line 182, in add_data
new_person = Employee(name=name, age=age, address=addr, city=city, state=state, zip=zip, ssn=ssn, phone=phone, cell=cell)
UnboundLocalError: local variable 'age' referenced before assignment
