main.py

import numpy
import argparse

from pandas import read_csv
from social_choice.profile import Profile


def main(args):
	data = read_csv(args.input_filepath, sep=args.sep)  # read the data file

	mayors = data.axes[0]								# line labels (mayors)
	mayors = list(mayors)								# cast to list

	# (mayors X votes) to (votes X mayors)
	data = numpy.array(data.T)  				    	# transpose

	if args.function == 'plurality':
		predictions = read_csv(args.predictions_filepath, sep=args.sep)  # get predicitons
		predictions = numpy.array(predictions.T)						 # transpose
		ranking = Profile.plurality(data, predictions)					 # get ranking
	else:
		profile = Profile.ballot_box(data)									 # create profile
		if args.function == 'kemeny_young':
			ranking = profile.kemeny_young()
		else:
			scorer = eval('profile.' + args.function) 	     			 # voting method
			ranking = profile.ranking(scorer)							 # get ranking

	# Map back to mayors labels
	for i in range(len(ranking)):
		j = ranking[i][0]						 	 # get mayor index
		mayors_label = "\"{}\"".format(mayors[j])    # mayors name
		ranking[i] = (mayors_label, ranking[i][1])	 # save mayor label

	# Order by label (tied cases)
	ranking.sort(key=lambda x: x[0])

	# Order by score
	ranking.sort(key=lambda x: x[1], reverse=True)

	# Save rank in file
	output = open(args.output_filepath, 'w')

	for mayor, score in ranking:
		output.write("{} {}\n".format(mayor, score))

	output.close()

	# If file to compare ranking exists...
	if not (args.compare_filepath is None):
		print("Comparing with {}...".format(args.compare_filepath))

		compare = open(args.compare_filepath, 'r')  # open file

		# Create an ordered rank
		comp_rank = list()

		for line in compare:
			k = line.split(" ")
			comp_rank.append((k[0], float(k[1])))

		compare.close()

		# Order compare rank
		comp_rank.sort(key=lambda x: x[1], reverse=True)  # by score

		position_count = 1   # for error msg
		error_count = 0	 	 # for error counting

		# For each ranked position...
		for i in range(len(comp_rank)):
			mayor1, score1 = ranking[i]    # info from generated rank
			mayor2, score2 = comp_rank[i]  # info from compare rank

			# Print message if it is different
			if mayor1 != mayor2:
				print("{} should be {} in line {}".format(mayor1, mayor2, position_count))
				error_count += 1  # update error count

			position_count += 1   # update position count

		print("{} errors of {}.".format(error_count, position_count-1))


if __name__ == "__main__":
	parser = argparse.ArgumentParser()

	#-input FILEPATH -f FUNCTION -o FILEPATH
	parser.add_argument("-i", "--input",
						dest="input_filepath",
						help="Path to input file.",
						required=True)

	parser.add_argument("-p", "--predictions",
						dest="predictions_filepath",
						help="Path to predictions file (required for plurality).")

	parser.add_argument("-s", "--sep",
						dest="sep",
						default="\t",
						help="File separator, i. e., ',' or '\t'...")

	parser.add_argument("-f", "--function",
						dest="function",
						help="Social choice function.",
						required=True,
						choices=['borda', 'plurality', 'simpson', 'copeland', 'dowdall', 'kemeny_young', 'symmetric_borda'])

	parser.add_argument("-o", "--output",
						dest="output_filepath",
						default="test_output.txt",
						help="Path to output file.")

	parser.add_argument("-c", "--compare",
						dest="compare_filepath",
						default=None,
						help="Path to rank file to be compared.")

	args = parser.parse_args()
	main(args)