psychopyでpythonコードを回す際、IOErrorと定義のエラーがでます。

###psychopyでpythonコードを回す際、IOErrorと定義のエラーがでます。
何故このエラーが出るのかわかりません。宜しくお願いします。

###発生している問題・エラーメッセージ

############## Running: C:\Users\hogehoge\Desktop\test.py ##############
Traceback (most recent call last):
  File "C:\Users\hogehoge\Desktop\test.py", line 43, in <module>
    with open(datafile,"w") as f:
IOError: [Errno 2] No such file or directory: u'C:\\Users\\hogehoge\\Desktop\\data/sub_2017_7_22_1942.csv'

######### Running: C:\Users\Miyuki KATO\Desktop\stim\katocode_0722.py ##########
list indices must be integers, not str
()

###実際のコード

#-*- coding: utf-8 -*-
from psychopy import visual, core, event, gui, data, misc
from psychopy import parallel
from psychopy.constants import *
import gc, numpy, os, random, time, csv, cv2, codecs, sys, random

try:
    results = []
    datafile = []
    # 参加者IDの取得
    try:
        expInfo=misc.fromFile('lastParams.pickle')
    except:
        expInfo={'Participant':''}

    expInfo['dateStr']=data.getDateStr()
    dlg=gui.DlgFromDict(expInfo,title='Experiment',fixed=['dateStr'])
    if dlg.OK:
        misc.toFile('lastParams.pickle',expInfo)
    else:
        core.quit()

    # 画面の準備
    myWin=visual.Window(fullscr=False,size=[800,800],monitor='Default',allowGUI=True,units='norm',color=(0,0,0))
    trials = visual.TextStim(myWin, text = '',pos = (0,0), color = (-1,-1,-1))
    stopwatch = core.Clock()

    #数字を出す
    diggits = ["1","2","3","4","5","6","7","8","9"]
    random.shuffle(diggits)
    trials.setText(diggits[1])
    trialStart = core.Clock()
    for i in diggits:
        targetNo = i
        log = targetNo
        while trialStart.getTime() <0.5:
            trials.draw()
            myWin.flip()

        results.append([diggits[1]])
        curD = os.getcwd()
        datafile = os.path.join(curD,'data/sub'+expInfo['Participant']+'_'+expInfo['dateStr']+'.csv')
        with open(datafile,"w") as f:
            f.write('trialList,log,answer,RT,\n')

            for r in results:
                f.write('{0}, {1}, {2}, {3}\n'.format(*r))
        datafile.close()

except TypeError, e:
    print e

###試したこと
タプルをリストに変換