I use Wikipedia's API to get information about a page.
The API gives me JSON like this:
"query":{
"pages":{
"188791":{
"pageid":188791,
"ns":0,
"title":"Vanit\u00e9",
"langlinks":[
{
"lang":"bg",
"*":"Vanitas"
},
{
"lang":"ca",
"*":"Vanitas"
},
ETC.
}
}
}
}
You can see the full JSON response.
I want to obtain all entries like:
{
"lang":"ca",
"*":"Vanitas"
}
but the number key ("188791") in the pages object is the problem.
I found Find a value within nested json dictionary in python that explains me how to do enumerate the values.
Unfortunately I get the following exception:
TypeError: 'dict_values' object does not support indexing
My code is:
json["query"]["pages"].values()[0]["langlinks"]
It's probably a dumb question but I can't find a way to pass in the page id value.
As long as you're only querying one page at a time, Simeon Visser's answer will work. However, as a matter of good style, I'd recommend structuring your code so that you iterate over all the returned results, even if you know there should be only one:
for page in data["query"]["pages"].values():
title = page["title"]
langlinks = page["langlinks"]
# do something with langlinks...
In particular, by writing your code this way, if you ever find yourself needing to run the query for multiple pages, you can do it efficiently with a single MediaWiki API request.
One solution is to use the indexpageids parameter, e.g.: http://fr.wikipedia.org/w/api.php?action=query&titles=Vanit%C3%A9&prop=langlinks&lllimit=500&format=jsonfm&indexpageids. It will add an array of pageids to the response. You can then use that to access the dictionary.
You're using Python 3 and values() now returns a dict_values instead of a list. This is a view on the values of the dictionary.
Hence that's why you're getting that error because indexing fails. Indexing is possible in a list but not a view.
To fix it:
list(json["query"]["pages"].values())[0]["langlinks"]
If you really want just one page arbitrarily, do that the way Simeon Visser suggested.
But I suspect you want all langlinks in all pages, yes?
For that, you want a comprehension:
[page["langlinks"] for page in json["query"]["pages"].values()]
But of course that gives you a 2D list. If you want to iterate over each page's links, that's perfect. If you want to iterate over all of the langlinks at once, you want to flatten the list:
[langlink for page in json["query"]["pages"]
for langlink in page["langlinks"].values()]
… or…
itertools.chain.from_iterable(page["langlinks"]
for page in json["query"]["pages"].values())
(The latter gives you an iterator; if you need a list, wrap the whole thing in list. Conversely, for the first two, if you don't need a list, just any iterable, use parens instead of square brackets to get a generator expression.)
