Trouble exporting from plot as csv

[Kevin Brockman]

Hello, I am attempting to acquire data from the plot generated by this code, but when I attempt to export it via the right click menu I get the following error:

>>> Traceback (most recent call last):

  File "C:\Users\KevinBrockman\AppData\Local\Continuum\Anaconda2\lib\site-packages\pyqtgraph\exporters\Exporter.py", line 72, in fileSaveFinished

    self.export(fileName=fileName, **self.fileDialog.opts)

  File "C:\Users\KevinBrockman\AppData\Local\Continuum\Anaconda2\lib\site-packages\pyqtgraph\exporters\CSVExporter.py", line 48, in export

    numRows = reduce(max, [len(d[0]) for d in data])

TypeError: object of type 'NoneType' has no len()

If anyone could help me get the export working it would be greatly appreciated.

from pyqtgraph.Qt import QtGui, QtCore

import numpy as np

import pyqtgraph as pg

import serial

app = QtGui.QApplication([])

p = pg.plot()

p.setWindowTitle('live plot from serial')

curve = p.plot()

data = [0]

raw=serial.Serial(8,115200)

#raw.open()

def update():

    global curve, data

    line = raw.readline()

    data.append(float(line))

    xdata = np.array(data, dtype='float64')

    curve.setData(xdata)

    app.processEvents()

timer = QtCore.QTimer()

timer.timeout.connect(update)

timer.start(0)

if __name__ == '__main__':

    import sys

    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):

        QtGui.QApplication.instance().exec_()