问题描述:

Hey there,

I'm trying to extract data from Wikipedia articles using its API (http://en.wikipedia.org/w/api.php) from a PHP script, but I always only seem to get a fraction of the real content.

For example, when trying :

$page=get_web_page("http://en.wikipedia.org/w/api.php?action=query&titles=Cat&prop=links&format=txt");

echo $page["content"];

This is what I get :

Array ( [query] => Array ( [pages] => Array ( [6678] => Array ( [pageid] => 6678 [ns] => 0 [title] => Cat [links] => Array ( [0] => Array ( [ns] => 0 [title] => 10th edition of Systema Naturae ) [1] => Array ( [ns] => 0 [title] => 3-mercapto-3-methylbutan-1-ol ) [2] => Array ( [ns] => 0 [title] => Abyssinian (cat) ) [3] => Array ( [ns] => 0 [title] => Actinidia polygama ) [4] => Array ( [ns] => 0 [title] => Adaptive radiation ) [5] => Array ( [ns] => 0 [title] => African Wildcat ) [6] => Array ( [ns] => 0 [title] => African wildcat ) [7] => Array ( [ns] => 0 [title] => Afro-Asiatic languages ) [8] => Array ( [ns] => 0 [title] => Age of Discovery ) [9] => Array ( [ns] => 0 [title] => Agouti signalling peptide ) ) ) ) ) [query-continue] => Array ( [links] => Array ( [plcontinue] => 6678|0|Albino ) ) )

I was requesting the full list of links on the "Cat" article, but I only seem to get the first 10 in alphabetic order.

This happens no matter the format I choose and even from the API itself (see http://en.wikipedia.org/w/api.php?action=query&titles=Cat&prop=links).

What is causing this restriction, and how can I fix it ?

网友答案:

If you look at the API manual, you will see that there is a pllimit option, which specifies how many links you want to be sent. You can get 500, or 5000 if you have a bot account, at one time.

You will see at the end of the data dump you provided the following: [plcontinue] => 6678|0|Albino ). You can provide this information to the server and get back more links from the page, starting from that point. So the next query you make would be

$page=get_web_page("http://en.wikipedia.org/w/api.php?action=query&titles=Cat&prop=links&format=txt&plcontinue=6678|0|Albino");

You will need to keep doing this until the server does not return a plcontinue value.

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