Специальной документации для api
нет.Документация в основном для отдельных классов и функций.Существует краткое объяснение различных путей импорта http://www.statsmodels.org/stable/importpaths.html
api.py в основном представляет собой набор импорта, например statsmodels api https://github.com/statsmodels/statsmodels/blob/master/statsmodels/api.py
from . import iolib
from . import datasets
from . import tools
from .tools.tools import add_constant, categorical
from . import regression
from .regression.linear_model import OLS, GLS, WLS, GLSAR
from .regression.recursive_ls import RecursiveLS
from .regression.quantile_regression import QuantReg
from .regression.mixed_linear_model import MixedLM
from .genmod import api as genmod
from .genmod.api import (GLM, GEE, OrdinalGEE, NominalGEE, families,
cov_struct,
BinomialBayesMixedGLM, PoissonBayesMixedGLM)
from . import robust
from .robust.robust_linear_model import RLM
from .discrete.discrete_model import (Poisson, Logit, Probit,
MNLogit, NegativeBinomial,
GeneralizedPoisson,
NegativeBinomialP)
from .discrete.count_model import (ZeroInflatedPoisson,
ZeroInflatedGeneralizedPoisson,
ZeroInflatedNegativeBinomialP)
from .tsa import api as tsa
...
Formula.api простоопределяет псевдонимы к from_formula
методам моделей https://github.com/statsmodels/statsmodels/blob/master/statsmodels/formula/api.py
from statsmodels.regression.linear_model import GLS
gls = GLS.from_formula
from statsmodels.regression.linear_model import WLS
wls = WLS.from_formula
from statsmodels.regression.linear_model import OLS
ols = OLS.from_formula
from statsmodels.regression.linear_model import GLSAR
glsar = GLSAR.from_formula
from statsmodels.regression.mixed_linear_model import MixedLM
mixedlm = MixedLM.from_formula
from statsmodels.genmod.generalized_linear_model import GLM
glm = GLM.from_formula
from statsmodels.robust.robust_linear_model import RLM
rlm = RLM.from_formula
from statsmodels.discrete.discrete_model import MNLogit
mnlogit = MNLogit.from_formula
from statsmodels.discrete.discrete_model import Logit
logit = Logit.from_formula
from statsmodels.discrete.discrete_model import Probit
probit = Probit.from_formula
from statsmodels.discrete.discrete_model import Poisson
poisson = Poisson.from_formula
from statsmodels.discrete.discrete_model import NegativeBinomial
negativebinomial = NegativeBinomial.from_formula
from statsmodels.regression.quantile_regression import QuantReg
quantreg = QuantReg.from_formula
from statsmodels.duration.hazard_regression import PHReg
phreg = PHReg.from_formula
from statsmodels.genmod.generalized_estimating_equations import (GEE,
OrdinalGEE, NominalGEE)
gee = GEE.from_formula
ordinal_gee = OrdinalGEE.from_formula
nominal_gee = NominalGEE.from_formula