Error sending - get request.

Question

Considering the code below:

path = "/admin/"
host = "192.168.1.1"

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, 80))

req = ("GET /"+path+" HTTP/1.1\n Host: %s \r\n\r\n", host)

s.send(req)
print(s.recv())
s.close()

I’m trying to send a simple request get but I’m not getting it. By concatenating tupla with string get the following error message:

Typeerror: must be string or path, not tuple

What’s wrong with this code?

Answer 1

The error must happen on the line s.send(req) - the socket.send method expects a string (or a buffer, not a "path" - will be that you transcribed the message incorrectly?).

What happens is that on the line you create the content of req you are not formatting the string, but creating a "tuple" - a sequence of two elements separated by "," - the formatting of strings using "%" uses the "%" operator between the string and the parameters, not a function call (or something like that - which is what you do there) - where the parameters are separated by ",".

That is, re-write your line that defines req to make it:

req = "GET /%s HTTP/1.1\n Host: %s \r\n\r\n" % (path, host)

instead of the way it is. The syntax of formatting strings with "%" has been deprecated in recent years by the new way of formatting strings with the "format" method: it is typed a little more, but it is a little less manageable to understand and read - and has more flexibility in advanced cases - in this case, your line would look like this (and you would not have confused yourself with the syntax as it did):

req = "GET /{} HTTP/1.1\n Host: {} \r\n\r\n".format(path, host)

Note that in both cases, as well as the "host""path" can also be passed as a formatting parameter - the possibility of a very flexible and feature-rich string formatting is one of the strengths of Python - and there are never reasons to use string concatenation with "+" just to interpolate values, as you did with the path - it is worth taking a look at the documentation of format: https://docs.python.org/2/library/string.html#format-string-syntax

Another tip: in addition to the error message, put also an indication of the line where the error occurred - the interpreeser tells you which one was.