diff --git a/arviz/data/__init__.py b/arviz/data/__init__.py
index 4d8d619c79..e08039916b 100644
--- a/arviz/data/__init__.py
+++ b/arviz/data/__init__.py
@@ -1,6 +1,6 @@
 """Code for loading and manipulating data structures."""
 from .inference_data import InferenceData
-from .io_netcdf import load_data, save_data
+from .io_netcdf import from_netcdf, to_netcdf, load_data, save_data
 from .datasets import load_arviz_data, list_datasets, clear_data_home
 from .base import numpy_to_data_array, dict_to_dataset
 from .converters import convert_to_dataset, convert_to_inference_data
@@ -13,8 +13,6 @@
 
 __all__ = [
     "InferenceData",
-    "load_data",
-    "save_data",
     "load_arviz_data",
     "list_datasets",
     "clear_data_home",
@@ -28,4 +26,8 @@
     "from_cmdstan",
     "from_pyro",
     "from_tfp",
+    "from_netcdf",
+    "to_netcdf",
+    "load_data",
+    "save_data",
 ]
diff --git a/arviz/data/datasets.py b/arviz/data/datasets.py
index d3bc2a72d6..afbb7bcd22 100644
--- a/arviz/data/datasets.py
+++ b/arviz/data/datasets.py
@@ -6,7 +6,7 @@
 import shutil
 from urllib.request import urlretrieve
 
-from .io_netcdf import load_data
+from .io_netcdf import from_netcdf
 
 LocalFileMetadata = namedtuple("LocalFileMetadata", ["filename", "description"])
 
@@ -143,7 +143,7 @@ def load_arviz_data(dataset=None, data_home=None):
     """
     if dataset in LOCAL_DATASETS:
         resource = LOCAL_DATASETS[dataset]
-        return load_data(resource.filename)
+        return from_netcdf(resource.filename)
 
     elif dataset in REMOTE_DATASETS:
         remote = REMOTE_DATASETS[dataset]
@@ -158,7 +158,7 @@ def load_arviz_data(dataset=None, data_home=None):
                 "file may be corrupted. Run `arviz.clear_data_home()` and try "
                 "again, or please open an issue.".format(file_path, checksum, remote.checksum)
             )
-        return load_data(file_path)
+        return from_netcdf(file_path)
     else:
         raise ValueError(
             "Dataset {} not found! The following are available:\n{}".format(
diff --git a/arviz/data/inference_data.py b/arviz/data/inference_data.py
index 8d80e96c83..ffc05d1a59 100644
--- a/arviz/data/inference_data.py
+++ b/arviz/data/inference_data.py
@@ -6,7 +6,7 @@
 class InferenceData:
     """Container for accessing netCDF files using xarray."""
 
-    def __init__(self, *_, **kwargs):
+    def __init__(self, **kwargs):
         """Initialize InferenceData object from keyword xarray datasets.
 
         Examples
diff --git a/arviz/data/io_cmdstan.py b/arviz/data/io_cmdstan.py
index 5ae7cfcc16..ba2cacba66 100644
--- a/arviz/data/io_cmdstan.py
+++ b/arviz/data/io_cmdstan.py
@@ -665,8 +665,8 @@ def _unpack_dataframes(dfs):
 
 
 def from_cmdstan(
-    *,
     posterior=None,
+    *,
     posterior_predictive=None,
     prior=None,
     prior_predictive=None,
diff --git a/arviz/data/io_emcee.py b/arviz/data/io_emcee.py
index 3d583e1ba6..1ccba5890a 100644
--- a/arviz/data/io_emcee.py
+++ b/arviz/data/io_emcee.py
@@ -54,7 +54,7 @@ def _verify_names(sampler, var_names, arg_names):
 class EmceeConverter:
     """Encapsulate emcee specific logic."""
 
-    def __init__(self, sampler, *_, var_names=None, arg_names=None, coords=None, dims=None):
+    def __init__(self, *, sampler, var_names=None, arg_names=None, coords=None, dims=None):
         var_names, arg_names = _verify_names(sampler, var_names, arg_names)
         self.sampler = sampler
         self.var_names = var_names
@@ -94,7 +94,7 @@ def to_inference_data(self):
         )
 
 
-def from_emcee(sampler, *, var_names=None, arg_names=None, coords=None, dims=None):
+def from_emcee(sampler=None, *, var_names=None, arg_names=None, coords=None, dims=None):
     """Convert emcee data into an InferenceData object.
 
     Parameters
@@ -111,5 +111,5 @@ def from_emcee(sampler, *, var_names=None, arg_names=None, coords=None, dims=Non
         Map variable names to their coordinates
     """
     return EmceeConverter(
-        sampler, var_names=var_names, arg_names=arg_names, coords=coords, dims=dims
+        sampler=sampler, var_names=var_names, arg_names=arg_names, coords=coords, dims=dims
     ).to_inference_data()
diff --git a/arviz/data/io_netcdf.py b/arviz/data/io_netcdf.py
index 8e2d665127..8dc1057ef7 100644
--- a/arviz/data/io_netcdf.py
+++ b/arviz/data/io_netcdf.py
@@ -1,9 +1,10 @@
 """Input and output support for data."""
+import warnings
 from .inference_data import InferenceData
 from .converters import convert_to_inference_data
 
 
-def load_data(filename):
+def from_netcdf(filename):
     """Load netcdf file back into an arviz.InferenceData.
 
     Parameters
@@ -14,7 +15,7 @@ def load_data(filename):
     return InferenceData.from_netcdf(filename)
 
 
-def save_data(data, filename, *, group="posterior", coords=None, dims=None):
+def to_netcdf(data, filename, *, group="posterior", coords=None, dims=None):
     """Save dataset as a netcdf file.
 
     WARNING: Only idempotent in case `data` is InferenceData
@@ -39,3 +40,58 @@ def save_data(data, filename, *, group="posterior", coords=None, dims=None):
     """
     inference_data = convert_to_inference_data(data, group=group, coords=coords, dims=dims)
     return inference_data.to_netcdf(filename)
+
+
+def load_data(filename):
+    """Load netcdf file back into an arviz.InferenceData.
+
+    Parameters
+    ----------
+    filename : str
+        name or path of the file to load trace
+
+    Note
+    ----
+    This function is deprecated and will be removed in 0.4.
+    Use `from_netcdf` instead.
+    """
+    warnings.warn(
+        "The 'load_data' function is deprecated as of 0.3.2, use 'from_netcdf' instead",
+        DeprecationWarning,
+    )
+    return from_netcdf(filename=filename)
+
+
+def save_data(data, filename, *, group="posterior", coords=None, dims=None):
+    """Save dataset as a netcdf file.
+
+    WARNING: Only idempotent in case `data` is InferenceData
+
+    Parameters
+    ----------
+    data : InferenceData, or any object accepted by `convert_to_inference_data`
+        Object to be saved
+    filename : str
+        name or path of the file to load trace
+    group : str (optional)
+        In case `data` is not InferenceData, this is the group it will be saved to
+    coords : dict (optional)
+        See `convert_to_inference_data`
+    dims : dict (optional)
+        See `convert_to_inference_data`
+
+    Returns
+    -------
+    str
+        filename saved to
+
+    Note
+    ----
+    This function is deprecated and will be removed in 0.4.
+    Use `to_netcdf` instead.
+    """
+    warnings.warn(
+        "The 'save_data' function is deprecated as of 0.3.2, use 'to_netcdf' instead",
+        DeprecationWarning,
+    )
+    return to_netcdf(data=data, filename=filename, group=group, coords=coords, dims=dims)
diff --git a/arviz/data/io_pymc3.py b/arviz/data/io_pymc3.py
index 8b658c29e5..e928fdf666 100644
--- a/arviz/data/io_pymc3.py
+++ b/arviz/data/io_pymc3.py
@@ -10,7 +10,7 @@ class PyMC3Converter:
     """Encapsulate PyMC3 specific logic."""
 
     def __init__(
-        self, *_, trace=None, prior=None, posterior_predictive=None, coords=None, dims=None
+        self, *, trace=None, prior=None, posterior_predictive=None, coords=None, dims=None
     ):
         self.trace = trace
         self.prior = prior
@@ -142,7 +142,7 @@ def to_inference_data(self):
         )
 
 
-def from_pymc3(*, trace=None, prior=None, posterior_predictive=None, coords=None, dims=None):
+def from_pymc3(trace=None, *, prior=None, posterior_predictive=None, coords=None, dims=None):
     """Convert pymc3 data into an InferenceData object."""
     return PyMC3Converter(
         trace=trace,
diff --git a/arviz/data/io_pyro.py b/arviz/data/io_pyro.py
index 9ca1d1fb08..db20545be5 100644
--- a/arviz/data/io_pyro.py
+++ b/arviz/data/io_pyro.py
@@ -28,7 +28,7 @@ def _get_var_names(posterior):
 class PyroConverter:
     """Encapsulate Pyro specific logic."""
 
-    def __init__(self, posterior, *_, coords=None, dims=None):
+    def __init__(self, *, posterior, coords=None, dims=None):
         """Convert pyro data into an InferenceData object.
 
         Parameters
@@ -103,7 +103,7 @@ def to_inference_data(self):
         )
 
 
-def from_pyro(posterior, *, coords=None, dims=None):
+def from_pyro(posterior=None, *, coords=None, dims=None):
     """Convert pyro data into an InferenceData object.
 
     Parameters
diff --git a/arviz/data/io_pystan.py b/arviz/data/io_pystan.py
index 00d9ec38a3..ee5828e845 100644
--- a/arviz/data/io_pystan.py
+++ b/arviz/data/io_pystan.py
@@ -15,7 +15,7 @@ class PyStanConverter:
 
     def __init__(
         self,
-        *_,
+        *,
         posterior=None,
         posterior_predictive=None,
         prior=None,
@@ -168,7 +168,7 @@ class PyStan3Converter:
     # pylint: disable=too-many-instance-attributes
     def __init__(
         self,
-        *_,
+        *,
         posterior=None,
         posterior_model=None,
         posterior_predictive=None,
@@ -519,8 +519,8 @@ def infer_dtypes(fit, model=None):
 
 # pylint disable=too-many-instance-attributes
 def from_pystan(
-    *,
     posterior=None,
+    *,
     posterior_predictive=None,
     prior=None,
     prior_predictive=None,
@@ -535,11 +535,11 @@ def from_pystan(
 
     Parameters
     ----------
-    posterior : StanFit4Model
+    posterior : StanFit4Model or stan.fit.Fit
         PyStan fit object for posterior.
     posterior_predictive : str, a list of str
         Posterior predictive samples for the posterior.
-    prior : StanFit4Model
+    prior : StanFit4Model or stan.fit.Fit
         PyStan fit object for prior.
     prior_predictive : str, a list of str
         Posterior predictive samples for the prior.
diff --git a/arviz/data/io_tfp.py b/arviz/data/io_tfp.py
index 61bcaaac55..364bfeeb12 100644
--- a/arviz/data/io_tfp.py
+++ b/arviz/data/io_tfp.py
@@ -12,8 +12,8 @@ class TfpConverter:
 
     def __init__(
         self,
-        posterior,
         *,
+        posterior,
         var_names=None,
         model_fn=None,
         feed_dict=None,
@@ -167,7 +167,7 @@ def to_inference_data(self):
 
 
 def from_tfp(
-    posterior,
+    posterior=None,
     *,
     var_names=None,
     model_fn=None,
diff --git a/arviz/tests/helpers.py b/arviz/tests/helpers.py
index dd6b8b08da..79fedda2d6 100644
--- a/arviz/tests/helpers.py
+++ b/arviz/tests/helpers.py
@@ -350,11 +350,7 @@ def stan_extract_dict(fit, var_names=None):
             continue
 
         # in future fix the correct number of draws if fit.save_warmup is True
-        new_shape = (
-            *fit.dims[fit.param_names.index(var)],
-            -1,
-            fit.num_chains,
-        )  # pylint: disable=protected-access
+        new_shape = (*fit.dims[fit.param_names.index(var)], -1, fit.num_chains)
         values = fit._draws[fit._parameter_indexes(var), :]  # pylint: disable=protected-access
         values = values.reshape(new_shape, order="F")
         values = np.moveaxis(values, [-2, -1], [1, 0])
diff --git a/arviz/tests/test_data.py b/arviz/tests/test_data.py
index a8814185bf..13fb6f91c6 100644
--- a/arviz/tests/test_data.py
+++ b/arviz/tests/test_data.py
@@ -12,10 +12,16 @@
     from_cmdstan,
     from_pymc3,
     from_pystan,
+    from_pyro,
     from_emcee,
+    from_netcdf,
+    to_netcdf,
+    load_data,
+    save_data,
     load_arviz_data,
     list_datasets,
     clear_data_home,
+    InferenceData,
 )
 from ..data.io_pystan import get_draws, get_draws_stan3  # pylint: disable=unused-import
 from ..data.datasets import REMOTE_DATASETS, LOCAL_DATASETS, RemoteFileMetadata
@@ -311,6 +317,78 @@ def test__verify_arg_names(self, obj):
         with pytest.raises(ValueError):
             from_emcee(obj, arg_names=["not", "enough"])
 
+    def test_inference_data(self, obj):
+        inference_data = self.get_inference_data(obj)
+        assert hasattr(inference_data, "posterior")
+
+
+class TestIONetCDFUtils:
+    @pytest.fixture(scope="class")
+    def data(self, draws, chains):
+        class Data:
+            model, obj = load_cached_models(eight_schools_params, draws, chains)["pymc3"]
+
+        return Data
+
+    def get_inference_data(self, data, eight_schools_params):  # pylint: disable=W0613
+        with data.model:
+            prior = pm.sample_prior_predictive()
+            posterior_predictive = pm.sample_posterior_predictive(data.obj)
+
+        return from_pymc3(
+            trace=data.obj,
+            prior=prior,
+            posterior_predictive=posterior_predictive,
+            coords={"school": np.arange(eight_schools_params["J"])},
+            dims={"theta": ["school"], "eta": ["school"]},
+        )
+
+    def test_io_function(self, data, eight_schools_params):
+        inference_data = self.get_inference_data(  # pylint: disable=W0612
+            data, eight_schools_params
+        )
+        assert hasattr(inference_data, "posterior")
+        here = os.path.dirname(os.path.abspath(__file__))
+        data_directory = os.path.join(here, "saved_models")
+        filepath = os.path.join(data_directory, "io_function_testfile.nc")
+        # az -function
+        to_netcdf(inference_data, filepath)
+        assert os.path.exists(filepath)
+        assert os.path.getsize(filepath) > 0
+        inference_data2 = from_netcdf(filepath)
+        assert hasattr(inference_data2, "posterior")
+        os.remove(filepath)
+        assert not os.path.exists(filepath)
+        # Test deprecated functions
+        save_data(inference_data, filepath)
+        assert os.path.exists(filepath)
+        assert os.path.getsize(filepath) > 0
+        inference_data3 = load_data(filepath)
+        assert hasattr(inference_data3, "posterior")
+        os.remove(filepath)
+        assert not os.path.exists(filepath)
+
+    def test_io_method(self, data, eight_schools_params):
+        inference_data = self.get_inference_data(  # pylint: disable=W0612
+            data, eight_schools_params
+        )
+        assert hasattr(inference_data, "posterior")
+        here = os.path.dirname(os.path.abspath(__file__))
+        data_directory = os.path.join(here, "saved_models")
+        filepath = os.path.join(data_directory, "io_method_testfile.nc")
+        if os.path.exists(filepath):
+            os.remove(filepath)
+        # InferenceData method
+        if os.path.exists(filepath):
+            os.remove(filepath)
+        inference_data.to_netcdf(filepath)
+        assert os.path.exists(filepath)
+        assert os.path.getsize(filepath) > 0
+        inference_data2 = InferenceData.from_netcdf(filepath)
+        assert hasattr(inference_data2, "posterior")
+        os.remove(filepath)
+        assert not os.path.exists(filepath)
+
 
 class TestPyMC3NetCDFUtils:
     @pytest.fixture(scope="class")
@@ -333,6 +411,10 @@ def get_inference_data(self, data, eight_schools_params):
             dims={"theta": ["school"], "eta": ["school"]},
         )
 
+    def test_posterior(self, data, eight_schools_params):
+        inference_data = self.get_inference_data(data, eight_schools_params)
+        assert hasattr(inference_data, "posterior")
+
     def test_sampler_stats(self, data, eight_schools_params):
         inference_data = self.get_inference_data(data, eight_schools_params)
         assert hasattr(inference_data, "sample_stats")
@@ -346,6 +428,22 @@ def test_prior(self, data, eight_schools_params):
         assert hasattr(inference_data, "prior")
 
 
+class TestPyroNetCDFUtils:
+    @pytest.fixture(scope="class")
+    def data(self, draws, chains):
+        class Data:
+            obj = load_cached_models(eight_schools_params, draws, chains)["pyro"]
+
+        return Data
+
+    def get_inference_data(self, data):
+        return from_pyro(posterior=data.obj)
+
+    def test_inference_data(self, data):
+        inference_data = self.get_inference_data(data)
+        assert hasattr(inference_data, "posterior")
+
+
 class TestPyStanNetCDFUtils:
     @pytest.fixture(scope="class")
     def data(self, draws, chains):
@@ -436,20 +534,24 @@ def test_inference_data(self, data, eight_schools_params):
         inference_data2 = self.get_inference_data2(data, eight_schools_params)
         inference_data3 = self.get_inference_data3(data, eight_schools_params)
         inference_data4 = self.get_inference_data4(data)
+        # inference_data 1
         assert hasattr(inference_data1.sample_stats, "log_likelihood")
         assert hasattr(inference_data1.posterior, "theta")
         assert hasattr(inference_data1.prior, "theta")
         assert hasattr(inference_data1.observed_data, "y")
+        # inference_data 2
         assert hasattr(inference_data2.posterior_predictive, "y_hat")
         assert hasattr(inference_data2.prior_predictive, "y_hat")
         assert hasattr(inference_data2.sample_stats, "lp")
         assert hasattr(inference_data2.sample_stats_prior, "lp")
         assert hasattr(inference_data2.observed_data, "y")
+        # inference_data 3
         assert hasattr(inference_data3.posterior_predictive, "y_hat")
         assert hasattr(inference_data3.prior_predictive, "y_hat")
         assert hasattr(inference_data3.sample_stats, "lp")
         assert hasattr(inference_data3.sample_stats_prior, "lp")
         assert hasattr(inference_data3.observed_data, "y")
+        # inference_data 4
         assert hasattr(inference_data4.posterior, "theta")
         assert hasattr(inference_data4.prior, "theta")
 
@@ -505,19 +607,19 @@ class TestTfpNetCDFUtils:
     @pytest.fixture(scope="class")
     def data(self, draws, chains):
         class Data:
-            obj = load_cached_models({}, draws, chains)[  # pylint: disable=E1120
+            # Returns result of from_tfp
+            obj = load_cached_models({}, draws, chains)[  # pylint: disable=no-value-for-parameter
                 "tensorflow_probability"
             ]
 
         return Data
 
-    def get_inference_data(self, data, eight_schools_params):  # pylint: disable=W0613
+    def get_inference_data(self, data):
         return data.obj
 
-    def test_inference_data(self, data, eight_schools_params):
-        inference_data1 = self.get_inference_data(  # pylint: disable=W0612
-            data, eight_schools_params
-        )
+    def test_inference_data(self, data):
+        inference_data = self.get_inference_data(data)
+        assert hasattr(inference_data, "posterior")
 
 
 class TestCmdStanNetCDFUtils: