Communication with Python

Projects Interfacing w/ Software on the Computer
1

Hi,
I'm new to Arduino and trying to teach myself to collect signals from Arduino using Python. Could somebody help me explain or troubleshoot this output?
I tested Arduino and it actually generating data. I am using Python 2.7 and Pyserial has been installed.
Thank you so much!!!
Hoang

CODE:
import serial
arduinoSerialData = serial.Serial('/dev/cu.usbmodem1411',9600)
while (1==1):
if (arduinoSerialData.inWaiting()>0):
myData = arduinoSerialData.readline()
print myData

OUTPUT:

RESTART: /Users/hoangnguyen/Desktop/Hoang Python code/arduino.py

Sometime, I receive this:
OUTPUT:

Traceback (most recent call last):
File "/Users/hoangnguyen/Desktop/Hoang Python code/python arduino communication.py", line 6, in
myData = arduinoSerialData.readline()
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/serial/serialposix.py", line 495, in read
raise SerialException('device reports readiness to read but returned no data (device disconnected or multiple access on port?)')
SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)

2

Things to check:

Are you able to open that com port using a terminal program?

Does it work if you run it with root/Admin rights?

Perhaps you should mention what kind of computer you are trying to run python on..

3

This Python - Arduino demo may give you some ideas.

...R

4

... or this Tutorials: Using Python with Arduino | Technology Tutorials