Iteration to place widgets in Tkinter and Pmw

Question

I have massively reduced the amount of repetitive code by using a loop in Python to create, format and store Pmw EntryFields in my project rather than build individual widgets. I even managed to place them in a linear fashion on the root window -- one under the other in column 0.

However, when I want to place them in two columns I cannot find a way to generate the following widget row and column coordinates

(0,0)(0 1),(1,0)(1,1)(2,0)(2,1) from the for loop. I used a workaround which was to type the above coordinates into a Python list and refer to the list.

import tkinter
import Pmw
import time



root=tkinter.Tk()                                         #Create a main GUI window

root.option_readfile('optionDB')                          #Override Windows default fonts
##root.resizable(width=False, height=False)                #Fix the window size in stone
root.iconbitmap('logo.ico')                               #add logo
titles=['a', 'b','c', 'd','e','f']                        #List ttitles of entry fields
**locations=[(0,0),(0,1),(1,0),(1,1),(2,0),(2,1)]**           #Entry locations
entry ={}                                                 #Container for referencing entry fieleds



for nextWidget in range(len(titles)):                    #Buils widgets on the page                        

    dummy_x= Pmw.EntryField(root,                                           #widget properties
                               labelpos = 'w',
                               label_text = titles[nextWidget],
                               label_fg="white",
                               entry_width=10
                           )
    Pmw.Color.changecolor(dummy_x.component("hull"),
                                 background="blue")

    **dummy_x.grid(row= locations[nextWidget][0],**
                      column=locations[nextWidget][1],
                      padx=10,pady=10
                )

    entry.update({titles[nextWidget]: dummy_x})                             #add to container


root.mainloop()        #run the venet loop

You can see in the main for loop I iterate over the list called locations and placing the values in the row, column attributes of the grid() option to place the widgets.

Question: To eliminate the locations list altogether is there a way to generate the sequence (0,0)(0 1),(1,0)(1,1)(2,0)(2,1) from the for loop iteself?

Answer 1

The general answer for all cases is you can use a for()

for this_row in range(3):
    for this_column in range(2):
         print this_row, this_column

or increment counters

this_row=0
this_column=0
for nextWidget in range(len(titles)): 
    ...
    this_column += 1
    if this_column > 1:
        this_row += 1
        this_column = 0

or test for nextWidget%2 = similar to above but divmod works better than modulus for this

for ctr in range(6):
    print divmod(ctr, 2)

Answer 2

(i/2, i%2) (python2), or (i//2, i%2) (python3) will will give you the numbers you want, if you only need two columns

$ python3 -i
Python 3.4.0 (default, Jun 19 2015, 14:20:21) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> for i in range(10):
...     print((i//2, i%2))
... 
(0, 0)
(0, 1)
(1, 0)
(1, 1)
(2, 0)
(2, 1)
(3, 0)
(3, 1)
(4, 0)
(4, 1)
>>>