def test_load_form_df():
"""Ensure reading dataset from pandas dataframe is OK."""
# DF creation.
ratings_dict = {
'itemID': [1, 1, 1, 2, 2],
'userID': [9, 32, 2, 45, '10000'],
'rating': [3, 2, 4, 3, 1]
}
df = pd.DataFrame(ratings_dict)
reader = Reader(rating_scale=(1, 5))
data = Dataset.load_from_df(df[['userID', 'itemID', 'rating']], reader)
# Assert split and folds can be used without problems
with pytest.warns(UserWarning):
data.split(2)
assert sum(1 for _ in data.folds()) == 2
# assert users and items are correctly mapped
trainset = data.build_full_trainset()
assert trainset.knows_user(trainset.to_inner_uid(9))
assert trainset.knows_user(trainset.to_inner_uid('10000'))
assert trainset.knows_item(trainset.to_inner_iid(2))
# assert r(9, 1) = 3 and r(2, 1) = 4
uid9 = trainset.to_inner_uid(9)
uid2 = trainset.to_inner_uid(2)
iid1 = trainset.to_inner_iid(1)
assert trainset.ur[uid9] == [(iid1, 3)]
assert trainset.ur[uid2] == [(iid1, 4)]
# assert at least rating file or dataframe must be specified
with pytest.raises(ValueError):
data = Dataset.load_from_df(None, None)
# mess up the column ordering and assert that users are not correctly
# mapped
data = Dataset.load_from_df(df[['rating', 'itemID', 'userID']], reader)
trainset = data.build_full_trainset()
with pytest.raises(ValueError):
trainset.to_inner_uid('10000')
def test_build_anti_testset():
ratings_dict = {
'itemID': [1, 2, 3, 4, 5, 6, 7, 8, 9],
'userID': [1, 2, 3, 4, 5, 6, 7, 8, 9],
'rating': [1, 2, 3, 4, 5, 6, 7, 8, 9]
}
df = pd.DataFrame(ratings_dict)
reader = Reader(rating_scale=(1, 5))
data = Dataset.load_from_df(df[['userID', 'itemID', 'rating']], reader)
with pytest.warns(UserWarning):
data.split(2)
trainset, __testset = next(data.folds())
# fill with some specific value
for fillvalue in (0, 42., -1):
anti = trainset.build_anti_testset(fill=fillvalue)
for (u, i, r) in anti:
assert r == fillvalue
# fill with global_mean
anti = trainset.build_anti_testset(fill=None)
for (u, i, r) in anti:
assert r == trainset.global_mean
expect = trainset.n_users * trainset.n_items
assert trainset.n_ratings + len(anti) == expect