MPContribs API get_entries() gives a maximum of 100 materials

I want to obtain a list of all materials satisfying my query. My current query results in 3880 materials, however I can only access a maximum of 100 of them regardless of what the query is. I would love it if someone could point me to what my issue could be.

I appreciate your time and consideration,
Daniel

Hi Daniel,

the responses from the MPContribs API are paginated and by default it returns your first 100 results. To loop through all the entries satisfying your query you can increase the per-page limit using the _limit or per_page parameters up to 500, and check the has_more field in the response to increment the page number as long as there are more results to return. However, as you already did, before you start looping through a potentially long list of results, you’ll want to tune the query to return a reasonable subset of contributions. Sometimes the first page (and a small per_page parameter) might be enough if descending or ascending order based on a field is requested via _sort. It’s also important to use the _fields parameter to only include the fields you need in the response. Below is an example for the carrier_transport dataset.

from mpcontribs.client import Client

query = {
    "project": "carrier_transport",
    "formula__contains": "Au",
    "data__PF__p__value__lt": 10,
    "data__PF__n__value__gt": 1,

    "_sort": "-data.S.n.value", # descending order
    "_limit": 170, # up to maximum 500 per request
    "_fields": [
        "identifier", "formula", "data.metal",
        "data.S.n.value", "data.S.p.value",
        "data.PF.n.value", "data.PF.p.value"
    ],
}

contributions = []
has_more, page = True, 1

with Client() as client:
    while has_more:
        resp = client.contributions.get_entries(
            page=page, **query
        ).result()
        contributions += resp["data"]
        has_more = resp["has_more"]
        page += 1
    
len(contributions)

HTH
thanks,
Patrick