In python 2.6, the following code:
import urlparse
qsdata = "test=test&test2=test2&test2=test3"
qs = urlparse.parse_qs(qsdata)
print qs
Gives the following output:
{'test': ['test'], 'test2': ['test2', 'test3']}
Which means that even though there is only one value for test, it is still being parsed into a list. Is there a way to ensure that if there's only one value, it is not parsed into a list, so that the result would look like this?
{'test': 'test', 'test2': ['test2', 'test3']}
A sidenote for someone just wanting a simple dictionary and never needing multiple values with the same key, try:
dict(urlparse.parse_qsl('foo=bar&baz=qux'))
This will give you a nice {'foo': 'bar', 'baz': 'qux'}. Please note that if there are multiple values for the same key, you'll only get the last one.
parse_qsl() give you a list of key-value pairs (and not a dict)?
dict(...) call around it. :)
urlparse module is renamed to urllib.parse in Python 3; hence, urllib.parse.parse_qsl(). Most important, the above approach wouldn't work in a scenario where a query param expects a list of values and may appear multiple times in the URL. For instance, this dict(urllib.parse.parse_qsl('foo=2&bar=7&foo=10')) would return {"foo":"10","bar":"7"} instead of {"foo":["2","10"],"bar":"7"}. The approach described in this answer, however, takes care of that.You could fix it afterwards...
import urlparse
qsdata = "test=test&test2=test2&test2=test3"
qs = dict( (k, v if len(v)>1 else v[0] )
for k, v in urlparse.parse_qs(qsdata).iteritems() )
print qs
However, I don't think I would want this. If a parameter that is normally a list happens to arrive with only one item set, then I would have a string instead of the list of strings I normally receive.
Expanding on @SingleNegationElimination answer a bit. If you do something like this, you can use only the last instance of a query parameter.
from urllib.parse import parse_qs
qsdata = "test=test&test2=test2&test2=test3"
dict((k, v[-1] if isinstance(v, list) else v)
for k, v in parse_qs(qsdata).items())
# Returns: {'test': 'test', 'test2': 'test3'}
Or you can retain only the first instance of a url parameter with the following:
from urllib.parse import parse_qs
qsdata = "test=test&test2=test2&test2=test3"
dict((k, v[0] if isinstance(v, list) else v)
for k, v in parse_qs(qsdata).items())
# Returns: {'test': 'test', 'test2': 'test2'}
