Question

I’m new to Python and seem to be hitting a problem. I’m trying to urlencode a user agent string…

import urllib

UserAgent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.3 Gecko/2008092417 Firefox/3.0.3'
print 'Agent: ' + UserAgent
print urllib.urlencode(UserAgent)

Which results in…

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.0.3 Gecko/2008092417 Firefox/3.0.3
Traceback (most recent call last):
  File "D:\Source\SomePath\test.py", line 7, in <module>
    print urllib.urlencode(UserAgent)
  File "C:\Python26\lib\urllib.py", line 1254, in urlencode
    raise TypeError
TypeError: not a valid non-string sequence or mapping object
Press any key to continue . . .

I can only assume that although the UserAgent is being printed correctly, I’m either missing some string-escaping option on the way in or making a fundamental mistake regarding urllib.urlencode()?

Answer 1

urllib.urlencode expects a mapping or sequence with two items each. as can be seen in the docs

In your code you would need to do the following:

urllib.urlencode({'Agent': UserAgent})