Python script read serial port, output to text file -

i'm trying read output serial port , write text file. far connects , prints output, can't figure out how send output text file (preferrable csv file).

#! /usr/bin/env python3 import serial import csv import sys import io  #excel stuff #from time import gmtime, strftime #resultfile=open('mydata.csv','wb') #end excel stuff  def scan():     """scan available ports. return list of tuples (num, name)"""     available = []     in range(256):         try:             s = serial.serial(i)             available.append( (i, s.portstr))             s.close()   # explicit close 'cause of delayed gc in java         except serial.serialexception:             pass     return available if __name__=='__main__':     print ("found ports:")     n,s in scan():         print ("(%d) %s" % (n,s))     selection = input("enter port number:")     try:         ser = serial.serial(eval(selection), 9600, timeout=1)         print("connected to: " + ser.portstr)     except serial.serialexception:         pass     while true:         # read line , convert b'xxx\r\n' xxx         line = ser.readline().decode('utf-8')[:-1]         if line:  # if isn't blank line                # f=open('testing.txt','w+')             print(line)               #print >> f.write('test.txt')  f.close()             #print(line)             #with open('test.csv', 'w') csv_file:                   #  writer = csv.dictwriter(csv_file, fieldnames=['header1'], lineterminator='\n') ser.close() 

import sys sys.stdout = open('file', 'w') print 'test' 

or redirect shell-output

$ python foo.py > file 

duplicate of this: redirect stdout file in python?