Python Question

Error when try send a file using paho.mqtt.python

I'm using paho.mqtt.python in python 2.7 and when I try to send a file (image), I see the next error:

Traceback (most recent call last):
File "/home/pi/Desktop/Device1/Scripts/mqtt_publish.py", line 39, in
mqttc.publish(MQTT_TOPIC,byteArr,0,True)
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 980, in publish
rc = self._send_publish(local_mid, topic, local_payload, qos, retain, False, info)
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 1988, in _send_publish
upayload = payload.encode('utf-8')
UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 0: ordinal not in range(128)


The publish script is the next:

# Import package
import paho.mqtt.client as mqtt

# Define Variables
MQTT_HOST = "192.168.1.39" #iot.eclipse.org
MQTT_PORT = 1883
MQTT_KEEPALIVE_INTERVAL = 45
MQTT_TOPIC = "Device1"
#MQTT_MSG = 25

def on_connect(mqttc, userdata, flags, rc):
#Subscribe to a Topic
mqttc.subscribe(MQTT_TOPIC, 0)
print("Connection returned result: "+connack_string(rc))

# Define on_publish event function
def on_publish(mqttc, userdata, mid):
print "Message Published..."
print("mid: " +str(mid))
mqttc.disconect()

# Initiate MQTT Client
mqttc = mqtt.Client(client_id="LCESS", clean_session=False)

# Register publish callback function
mqttc.on_publish = on_publish
mqttc.on_connect = on_connect
# Connect with MQTT Broker
# probar mqttc.username_pw_set(username, password)
mqttc.connect(MQTT_HOST, MQTT_PORT, MQTT_KEEPALIVE_INTERVAL)

# Publish message to MQTT Broker
f= open("/home/pi/Desktop/images/image.jpg")
filecontent = f.read()
byteArr = bytes(filecontent)

mqttc.publish(MQTT_TOPIC,byteArr,0,True)

Answer

The solution is the following:

replace:

byteArr = bytes(filecontent)

to

byteArr = bytearray(filecontent)

and replace:

connack_string(rc)

to

mqtt.connack_string(rc)

Because I've imported the module: import paho.mqtt.client as mqtt

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