newbie with major "lambda" problem (perhaps a scope problem as well)

[Joe Potter]

Hello all,

The following code comes from "Programing Python 2nd Edition" by Lutz.

My problem is with the Button function calls 
in the   "  if  __name__ == '__main__':  " part of the code. 
If one uses the lambda call as does Lutz, 
then everything works like a champ.

However, a direct call to the function does not seem to do anything. No error
messages --- just no action.


This leads me to believe that I am missing some "VERY BIG DEAL" (TM) in Python.

Can someone tell this fool what he is missing?


Thanks in advance, Joe Potter



##### here is code in question
############################


# use StringVar variables and layout by columns

from Tkinter import *
from quitter import Quitter
fields = 'Name', 'Job', 'Pay'
info = []


def fetch(variables):
    info = []
    for variable in variables:
        #print 'Input => "%s"' % variable.get()      # get from var
        info.append(variable.get())
    for c in range(len(info)):
        print info[c]
              
def makeform(root, fields):
    form = Frame(root)                              # make outer frame
    left = Frame(form)                              # make two columns
    rite = Frame(form)
    form.pack(fill=X) 
    left.pack(side=LEFT)
    rite.pack(side=RIGHT, expand=YES, fill=X)       # grow horizontal

    variables = []
    for field in fields:
        lab = Label(left, width=5, text=field)      # add to columns
        ent = Entry(rite)
        lab.pack(side=TOP)
        ent.pack(side=TOP, fill=X)                  # grow horizontal
        var = StringVar()
        ent.config(textvariable=var)                # link field to var
        var.set('enter here')
        variables.append(var)
    return variables

if __name__ == '__main__':
    root = Tk()
    vars = makeform(root, fields)


    # the "button" below works like a champ !!
    #Button(root, text='Fetch', 
                 #command=(lambda v=vars: fetch(v))).pack(side=LEFT)

    # the "button" below does not do anything ??????
    Button(root, text='Fetch', command=(fetch(vars))).pack(side=LEFT)



    Quitter(root).pack(side=RIGHT)
    root.bind('<Return>', (lambda event, v=vars: fetch(v)))   
    root.mainloop()
############################################
####### end code