Python urllib problem

Question

I have a problem with the urllib library in Python 3.

This is my code:

!/usr/bin/python3
import http.client
import urllib.request
import urllib.parse
import time
from datetime import datetime
import json
device = "[email protected]" 
api_key = ""
api_url = "http://api.carriots.com/devices"
#Parameters - Body
timestamp = int(time.time())
params = {"order": -1}
binary_data = json.dumps(params).encode('ascii')
#Header
header = { "User-Agent": "raspberrycarriots",
 "Content-Type": "application/json",
 "carriots.apikey": api_key}
#Request
req= urllib.request.Request(api_url, binary_data, header)
print(req)
f = urllib.request.urlopen(req)
#Print response
print(f.read().decode('utf-8'))

This is the answer that I got:

urllib.request.Request object at 0x74cd2370>
Traceback (most recent call last):
File "/usr/lib/python3.4/urllib/request.py", line 1174, in do_open
h.request(req.get_method(), req.selector, req.data, headers)
File "/usr/lib/python3.4/http/client.py", line 1090, in request
self._send_request(method, url, body, headers)
File "/usr/lib/python3.4/http/client.py", line 1128, in _send_request
self.endheaders(body)
File "/usr/lib/python3.4/http/client.py", line 1086, in endheaders
self._send_output(message_body)
File "/usr/lib/python3.4/http/client.py", line 924, in _send_output
self.send(msg)
File "/usr/lib/python3.4/http/client.py", line 859, in send
self.connect()
File "/usr/lib/python3.4/http/client.py", line 836, in connect
self.timeout, self.source_address)
File "/usr/lib/python3.4/socket.py", line 491, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
File "/usr/lib/python3.4/socket.py", line 530, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
 File "/home/pi/Documents/Python Programs/demoget.py", line 31, in <module>
 f = urllib.request.urlopen(req)
 File "/usr/lib/python3.4/urllib/request.py", line 153, in urlopen
 return opener.open(url, data, timeout)
 File "/usr/lib/python3.4/urllib/request.py", line 455, in open
 response = self._open(req, data)
 File "/usr/lib/python3.4/urllib/request.py", line 473, in _open
 '_open', req)
 File "/usr/lib/python3.4/urllib/request.py", line 433, in _call_chain
 result = func(*args)
 File "/usr/lib/python3.4/urllib/request.py", line 1202, in http_open
 return self.do_open(http.client.HTTPConnection, req)
 File "/usr/lib/python3.4/urllib/request.py", line 1176, in do_open
 raise URLError(err)
urllib.error.URLError: <urlopen error [Errno -2] Name or service not known>

I hope you can help me.

Answer 1

Your program still works today with that same API key. The output is:

<urllib.request.Request object at 0x104a77940>
{"total_documents":2,"result":[{"_id":"590327165c5d7564440e39f7","n_str":1494722195,"updated_at":1494722209,"type":"Raspberry Pi","owner":"yukardo","id_group":"[email protected]","id_model":null,"lon":null,"id_asset":null,"frequency_stream":1440,"sensor":"Other","before_status":"ok","status":"disconnected","description":null,"id_developer":"[email protected]","frequency_status":1440,"lat":null,"properties":[],"name":"Miriadax","checksum":null,"created_at":1493378838,"enabled":true,"time_zone":"America\/Santo_Domingo","updater":"system","_ls":{"_id":"5907c3c45c5d75f37222897b","id_d":"[email protected]","l_str":1494635795,"n_str":1494722195,"d":1,"owner":"system","updater":"system"}},{"_id":"592988b05c5d758d3d0c7f92","n_str":1500600100,"updated_at":1500600129,"type":"Other","owner":"yukardo","id_group":"[email protected]","id_model":null,"lon":null,"id_asset":null,"frequency_stream":1440,"sensor":"Other","before_status":"ok","status":"disconnected","description":null,"id_developer":"[email protected]","frequency_status":1440,"lat":null,"properties":[],"name":"WallE","checksum":null,"created_at":1495894192,"enabled":true,"time_zone":"America\/Santo_Domingo","updater":"system","_ls":{"_id":"592e1d925c5d755b1aa852b4","id_d":"[email protected]","l_str":1500513700,"n_str":1500600100,"d":1,"owner":"system","updater":"system"}}]}

(The first # byte of your program appears to be cut off, but I'll assume that was a copypaste accident.)

However, if api.carriots.com were unreachable you would get exactly the Name or service not known error as you saw. Run ping api.carriots.com, check your Pi's ethernet/WiFi configuration as necessary, and retry once networking issues are resolved.