Python script to find, combine and calculate the average values of csv data for the combustion engine intern/course at the at the University of Bayreuth. Usage as follows: python calc_average.py /folder list. Next, accept with (y) yes, or deny with (n) - Make sure you made a copy of the files before!

calc_average.py

#! /usr/bin/env python

# usage: python calc_average.py folder list
# y / n

import os, sys
from decimal import *

def csv_average(file_input, file_folder, amount):
	file_name = file_input
	file_amount = amount
	file_folder = file_folder

	suffix = ".csv"
	output_file = file_name+suffix

	li = []

	for files in range(file_amount):
		if files < 9:
			li.append(file_folder+"/"+file_name+"_0"+str(files+1)+suffix)
		else:
			li.append(file_folder+"/"+file_name+"_"+str(files+1)+suffix)

	if os.path.exists(output_file):
		f = file(output_file, "r+")
	else:
		f = file(output_file, "w+")

	li_values = [[] for i in range(int(file_amount))] 

	# load csv to list
	for item in range(len(li)):
		f = open(li[item])
		y = f.readlines()

		for item_val in range(len(y)):
			z = y[item_val].split(',')
			if len(z) is not 2:
				pass
			else:
				try:
					li_values[item].append(
						[
							[float(z[0])], 
							[float(z[1])]
						])
				except:
					pass

		print "> processing: %s" % li[item]

	li_average = [
		[],[]
	]

	el1 = 0.00
	el2 = 0.00

	len_values = len(li_values)

	# 7818
	for element in range(len(li_values[0])):
		
		# 10
		for item in range(len_values):
			el1 = el1 + li_values[item][element][0][0]
			el2 = el2 + li_values[item][element][1][0]
		
		#print element, el1/file_amount, el2/file_amount
		li_average[0].append(float(el1/len_values))
		li_average[1].append(float(el2/len_values))
		
		el1 = 0.00
		el2 = 0.00

	fo = open(output_file, 'w+')
	fo.write("Zeit, Kanal A")
	fo.write("\n")
	fo.write("(ms), (V)")
	fo.write("\n")

	for items in range(len(li_average[0])):
		fo.write("%s" % li_average[0][items])
		fo.write(",")
		fo.write("%s" % li_average[1][items])
		fo.write("\n")

	print "done"
	print "saved as: %s" % output_file

def main():
	if len(sys.argv) > 1:
		file_folder = sys.argv[1]
		file_input = sys.argv[2]

		file_names_temp = []
		file_names = []

		file_count = 0

		if sys.argv[2] == "list":

			for dirname, dirnames, filenames in os.walk(file_folder):
				for filename in filenames:
					file_names_temp.append(filename[:-7])
					# print os.path.join(dirname, filename)

			for item in file_names_temp:
				if item not in file_names:
					file_names.append(item)
					file_count = 0
				else:
					file_count = file_count + 1

			file_count = file_count + 1

			input = raw_input("found %i items, do average calculation for each file? (y) / (n): " % len(file_names))
			
			if input == "y":
				for item in file_names:
					print "----"
					print item
					csv_average(item, file_folder, file_count)

			if input == "n":
				print "bye"
				exit(0)

	else:
		print "no file name"
		exit

if __name__ == '__main__':
    main()