Set difference: Data provided from two big files with one number at a line

Today, I had to find out difference between two huge lists of numbers.
Numbers are 17 digits long and list are of around 1 lac.

PS: I'm documenting both versions here for my future reference.

I used python, because diff doesn't felt good for me. because it will print both ins and outs of both files. Also, I ruled out diff's possibility, because I didn't felt it will work at that time.

	"""
	# A shorter ugly version
	total = set([i.strip() for i in open("total.txt").readlines()]) # list comprehension to remove \r\n from lines
	coupon = set([i.strip() for i in open("coupon.txt").readlines()]) # set to remove duplicates and do set difference
	open("result.txt", "w").write('\n'.join(sorted(total-coupon))) # use set difference and use sorted to sort then write in separate lines
	"""
	### Now see same thing above in beautiful & readable way
	# reading file content into list
	total = open("total.txt").readlines()
	coupon = open("coupon.txt").readlines()
	# striping "\r\n and/or spaces at ends from each line
	total = [i.strip() for i in total]
	coupon = [i.strip() for i in coupon]
	#creating sets from list
	total_set = set(total)
	coupon_set = set(coupon)
	# finding set difference
	difference = total_set - coupon_set
	#sorting the result
	sorted_difference = sorted(difference)
	# writing the result back into file, one number in a line
	f_result = open("result.txt", "w")
	f_result.write('\n'.join(sorted_diffrence))
	f_result.close()

view raw setdifferencenum.py hosted with ❤ by GitHub

Later, at home: I give diff a try.
Yes, it's not that beautiful as in python. I'd cut and sed a bit.
But still, it's a "one liner" and I like 'em a lot.

	$ ## First see the one liner
	$ diff -bBw total.txt coupon.txt | grep '<' | cut -d'<' -f2 | sort -nu | sed -e 's/^[ \t]*//' > result.txt
	$ ## Now dissect it
	$ diff -bBw total.txt coupon.txt # it will give us diff, but there is changes for both files
	$ diff -bBw total.txt coupon.txt | grep '<' # numbers which are not in total but in coupon
	$ diff -bBw total.txt coupon.txt | grep '<' | cut -d'<' -f2 # remove leading '<' printed by diff
	$ diff -bBw total.txt coupon.txt | grep '<' | cut -d'<' -f2 | sort -nu # numerically sort & remove duplicates
	$ diff -bBw total.txt coupon.txt | grep '<' | cut -d'<' -f2 | sort -nu | sed -e 's/^[ \t]*//' # remove leading space
	$ diff -bBw total.txt coupon.txt | grep '<' | cut -d'<' -f2 | sort -nu | sed -e 's/^[ \t]*//' > result.txt # write result into a file

view raw setdifferencenum.sh hosted with ❤ by GitHub