Set port in requests

问题:

I'm attempting to make use of cgminer's API using Python. I'm particularly interested in utilizing the requests library.

I understand how to do basic things in requests, but cgminer wants to be a little more specific. I'd like to shrink

import socket
import json

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('localhost', 4028))

sock.send(json.dumps({'command': 'summary'}))

using requests instead.

How does one specify the port using that library, and how does one send such a json request and await a response to be stored in a variable?

回答1:

Request is an HTTP library.

You can specify the port in the URL http://example.com:4028/....

But, from what I can read in a hurry here cgminer provides a RPC API (or JSON RPC?) not an HTTP interface.

回答2:

As someone who has learned some of the common pitfalls of python networking the hard way, I'm adding this answer to emphasize an important-but-easy-to-mess-up point about the 1st arg of requests.get():

localhost is an alias which your computer resolves to 127.0.0.1, the IP address of its own loopback adapter. foo.com is also an alias, just one that gets resolved further away from the host.

requests.get('foo.com:4028')                #<--fails
requests.get('http://foo.com:4028')         #<--works usually  

& for loopbacks:

requests.get('http://127.0.0.1:4028')       #<--works
requests.get('http://localhost:4028')       #<--works

this one requires import socket & gives you the local ip of your host (aka, your address within your own LAN); it goes a little farther out from the host than just calling localhost, but not all the way out to the open-internet:

requests.get('http://{}:4028'.format(socket.gethostbyname(socket.gethostname())))  #<--works

回答3:

You can specify the port for the request with a colon just as you would in a browser, such as r = requests.get('http://localhost:4028'). This will block until a response is received, or until the request times out, so you don't need to worry about awaiting a response.

You can send JSON data as a POST request using the requests.post method with the data parameter, such as

import json, requests
payload = {'command': 'summary'}
r = requests.post('http://localhost:4028', data=json.dumps(payload))

Accessing the response is then possible with r.text or r.json().

Note that requests is an HTTP library - if it's not HTTP that you want then I don't believe it's possible to use requests.