Python- making a set from a text file

I have a text file. The guts of it look like this.

(0, 19, 0), (0, 20, 0), (0, 21, 1), (0, 22, 0), (0, 24, 3), (0, 27, 0), (0, 29, 2), (0, 35, 2), (0, 36, 1),...)

Anyway, how do I put these values into a set on python 2?

My most recent attempt was

om_set = set(open('Rye Grass.txt').read()

EDIT: This is the code I used to get my text file. import cv2 import numpy as np import time

om=cv2.imread('spectrum1.png')
om=om.reshape(1,-1,3)
om_list=om.tolist()
om_tuple={tuple(item) for item in om_list[0]}
om_set=set(om_tuple)

im=cv2.imread('1.jpg')        
im=cv2.resize(im,(100,100))         
im= im.reshape(1,-1,3)
im_list=im.tolist()
im_tuple={tuple(item) for item in im_list[0]}
ColourCount= om_set & set(im_tuple)
with open('Weedlist', 'a') as outputfile:
    output = ', '.join([str(tup) for tup in sorted(ColourCount)])
    outputfile.write(output)
print 'done'

im=cv2.imread('2.jpg')        
im=cv2.resize(im,(100,100))         
im= im.reshape(1,-1,3)
im_list=im.tolist()
im_tuple={tuple(item) for item in im_list[0]}
ColourCount= om_set & set(im_tuple)
with open('Weedlist', 'a') as outputfile:
    output = ', '.join([str(tup) for tup in sorted(ColourCount)])
    outputfile.write(output)
print 'done'