How to POST - API in thingspeak.comusing urllib in Python

Question

I am working on a project where I have to get data from a website and then post it to a different website. At the moment I am still new, so I am using a thingspeak.com account to experiment on posting, and I am also following the same example used in the documentations of urllib, https://docs.python.org/2/library/urllib.html.

params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
# I am using this to check => eggs=2&bacon=0&spam=1
print params 
f = urllib.urlopen("https://api.thingspeak.com/update?key=8TU6AC31T81MV52N&field1=",params)
print f.read()

However, when I check my thingspeak website http://api.thingspeak.com/channels/42628/feed.json?key=8TU6AC31T81MV52N, I will get this for that specific entry

{"created_at":"2015-06-17T10:05:12Z","entry_id":19,"field1":""}

Supposedly, or at least how I understood it, params should be posted to the website but I don't understand why I get the empty string. Also, it doesn't work if I loop it, it only works for the first iteration posting the empty string, and the rest are I will get 0 read from f.read(). What's the problem?! :\

All help is much appreciated. Also please correct if by I was mistaken.

Answer 1

You are sending the query parameter named field1 in the URL, but it is set to any empty string. Hence field1 is set to "" by thingspeak.com. Those values you pass in params are sent in the body of the HTTP POST request, they are not somehow appended to the URL.

You can set the field in one of two ways:

• a GET request using:

  f = urllib.urlopen("https://api.thingspeak.com/update?key=8TU6AC31T81MV52N&field1=my+value")
  

  which includes the API key and a value for field1.

• a POST request:

  params = urllib.urlencode({'key': '8TU6AC31T81MV52N', 'field1': 'my value'})
  f = urllib.urlopen("https://api.thingspeak.com/update", data=params)
  

thinkspeak will accept query parameters in the URL with a POST request, e.g. you can pass field1 in the URL and the API key in the body:

params = urllib.urlencode({'key': '8TU6AC31T81MV52N'})
f = urllib.urlopen("https://api.thingspeak.com/update?field1=hello", data=params)

However, playing around with the API it looks like it will only accept the query parameter named field1. All other fields are ignored, even those documented such as field2, field3, etc.