repeat_lines.py

# creating the output file
outputFile = open('C:/Users/user/Desktop/Lorem_output.txt', "w")

# reading the input file
inputFile = open('C:/Users/user/Desktop/Lorem_input.txt', "r")

# holds lines already seen
lines_seen_so_far = set()

# iterating each line in the file
for line in inputFile:

	# checking if line is unique
	if line not in lines_seen_so_far:

		# write unique lines in output file
		outputFile.write(line)

		# adds unique lines to lines_seen_so_far
		lines_seen_so_far.add(line)	

# closing the file
inputFile.close()
outputFile.close()