How do I get rid of spaces in the 'message' when sending SMS via Kannel

Question

I've setup Kannel in Ubuntu using a USB Modem and I can send SMS via the browser using the URL as seen below

localhost:13013/cgi-bin/sendsms?username=kannel&password=kannel&to=+254781923855&text='Kid got swag'

In python, I have the following script which works only if the message to be sent does not have spaces.

import urllib.request
def send_sms(mobile_no, message):
    url="http://%s:%d/cgi-bin/sendsms?username=%s&password=%s&to=%s&text=%s" \
    % ('localhost', 13013, 'kannel', 'kannel', str(mobile_no), message)
    f = urllib.request.urlopen(url)
    print("sms sent")

If I call the function with NO spaces in the message, it works and the message is sent.

sms.send_sms('+254781923855', 'kid_got_swag')

If I have spaces in the message, it fails with the error belw

sms.send_sms('+254781923855', 'kid got swag')

Traceback (most recent call last):
File "/home/lukik/workspace/projx/src/short_message.py", line 24, in <module>
sms.send_sms('+254781923855', 'kid got swag')
File "/home/lukik/workspace/projx/src/short_message.py", line 18, in send_sms
f = urllib.request.urlopen(url)
File "/usr/lib/python3.2/urllib/request.py", line 139, in urlopen
return opener.open(url, data, timeout)
File "/usr/lib/python3.2/urllib/request.py", line 376, in open
response = meth(req, response)
File "/usr/lib/python3.2/urllib/request.py", line 488, in http_response
'http', request, response, code, msg, hdrs)
File "/usr/lib/python3.2/urllib/request.py", line 414, in error
return self._call_chain(*args)
File "/usr/lib/python3.2/urllib/request.py", line 348, in _call_chain
result = func(*args)
File "/usr/lib/python3.2/urllib/request.py", line 496, in http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 400: Bad Request

I've tried other variants of calling urllib but they all fail coz of the spaces in the message....

Answer 1

In your request you send via browser, the message is inside quotes -

&text='Kid got swag'

Try that in your request -

url="http://%s:%d/cgi-bin/sendsms?username=%s&password=%s&to=%s&text='%s'" \
    % ('localhost', 13013, 'kannel', 'kannel', str(mobile_no), message)

Notice the single quotes at &text='%s'.

PS: I'd recommend using requests for requests like this. You could construct your urls better that way, like this -

>>> payload = {'key1': 'value1', 'key2': 'value2'}
>>> r = requests.get("http://httpbin.org/get", params=payload)

Answer 2

URLs are not permitted to contain spaces. When you tried in your browser, the browser took care of correctly encoding the URL before issuing the request. In your program you need to encode the URL. Fortunately urllib has functions built-in to take careof the details.

http://docs.python.org/3.3/library/urllib.parse.html#url-quoting

Answer 3

You need to URL-encode the values you pass as parameters, otherwise a broken URL gets constructed, that's why the request fails. I believe urllib.parse.urlencode does what you need.