def build_user_features(self, data, normalize=True):
builder = _FeatureBuilder(<EOL>self._user_id_mapping,<EOL>self._user_feature_mapping,<EOL>self._user_identity_features,<EOL>normalize,<EOL>"<STR_LIT:user>",<EOL>)<EOL>return builder.build(data)<EOL>
Build a user features matrix out of an iterable of the form
(user id, [list of feature names]) or (user id, {feature name: feature weight}).

Parameters
----------

data: iterable of the form
    (user id, [list of feature names]) or (user id,
    {feature name: feature weight}).
    User and feature ids will be translated to internal indices
    constructed during the fit call.
normalize: bool, optional
    If true, will ensure that feature weights sum to 1 in every row.

Returns
-------

feature matrix: CSR matrix (num users, num features)
    Matrix of user features.