I have a simple script that takes user input (for an Employee) such as
name, age, etc then puts in an sqlite3 database. The script worked fine
until I realized one problem. The age input field is defined in SQLAlchemy
as an Integer, so if a user inputs a string instead of a number in that
field, an error will occur (in IDLE). . .
So, I put a try: except clause in the code for the age field in the
add_data method. . .
try:
age = self.age_var.get()
except ValueError:
showinfo("Error:", "Please Enter A Number In Age Field.")
If the user inputs a string (instead of an Int) the showinfo dialogue box
opens as it should, but when the user clicks "ok" in the box, I get the
error "UnboundLocalError: local variable 'age' referenced before
assignment". I tried using a default value above the try: except clause
(age=0), which corrects the error, but causes "0" to be saved in the
database instead of letting the user choose another value. I want to figure
why I get the error (with the try: except clause) and what exactly to do
about it. Thanks in advance for any help!
Here's the original code (without the try: except clause above). . .Just
put the try: except clause in the age variable in the add_data method as
shown above to get the error.
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()
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