Do not convert last states to dask DataFrame. (#134)

docs/source/changes.rst

@@ -13,6 +13,8 @@ all releases are available on `Anaconda.org
 - :gh:`131` moves the parsing of the virus strain infectiousness factor to the
   simulation.
 - :gh:`132` sets initialized countdowns to -9,999.
+- :gh:`134` changes that the last states are returned as a ``pandas.DataFrame`` and not
+  as a ``dask.dataframe``.
 
 
 0.0.9 - 2021-05-28

src/sid/simulate.py

@@ -644,8 +644,7 @@ def _simulate(
         time_series = _prepare_time_series(path, columns_to_keep, states)
         results["time_series"] = time_series
     if return_last_states:
-        last_states = _prepare_last_states(path, states)
-        results["last_states"] = last_states
+        results["last_states"] = states
     if period_outputs:
         results["period_outputs"] = evaluated_period_outputs
 
@@ -1067,33 +1066,6 @@ def _prepare_time_series(output_directory, columns_to_keep, last_states):
     return time_series
 
 
-def _prepare_last_states(output_directory, last_states):
-    """Prepare the last_states for the simulation results.
-
-    Args:
-        output_directory (pathlib.Path): Path to output directory.
-        columns_to_keep (list): List of variables which should be kept.
-        last_states (pandas.DataFrame): The states from the last period.
-
-    Returns:
-        dask.dataframe: The DataFrame with the last states
-
-
-    """
-    categoricals = {
-        column: last_states[column].cat.categories.shape[0]
-        for column in last_states.select_dtypes("category").columns
-    }
-
-    last_states.to_parquet(output_directory / "last_states" / "last_states.parquet")
-    last_states = dd.read_parquet(
-        output_directory / "last_states" / "last_states.parquet",
-        categories=categoricals,
-        engine="fastparquet",
-    )
-    return last_states
-
-
 def _process_saved_columns(
     saved_columns: Union[None, Dict[str, Union[bool, str, List[str]]]],
     initial_state_columns: List[str],

tests/test_plotting.py

@@ -65,7 +65,7 @@ def test_plot_infection_rates_by_contact_models(params, initial_states, tmp_path
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)

tests/test_rapid_tests.py

@@ -35,7 +35,7 @@ def test_simulate_rapid_tests(params, initial_states, tmp_path):
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)
@@ -77,7 +77,7 @@ def test_simulate_rapid_tests_with_reaction_models(params, initial_states, tmp_p
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)

tests/test_seasonality.py

@@ -26,7 +26,7 @@ def test_simulate_a_simple_model(params, initial_states, tmp_path):
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)

tests/test_simulate.py

@@ -31,7 +31,7 @@ def test_simulate_a_simple_model(params, initial_states, tmp_path):
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)
@@ -55,7 +55,7 @@ def test_resume_a_simulation(params, initial_states, tmp_path):
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)
@@ -77,7 +77,7 @@ def test_resume_a_simulation(params, initial_states, tmp_path):
     resumed_result = resumed_simulate(params)
 
     resumed_time_series = resumed_result["time_series"].compute()
-    resumed_last_states = resumed_result["last_states"].compute()
+    resumed_last_states = resumed_result["last_states"]
 
     for df in [resumed_time_series, resumed_last_states]:
         assert isinstance(df, pd.DataFrame)
@@ -110,7 +110,7 @@ def test_simulate_a_simple_model_without_assort_by(params, initial_states, tmp_p
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)
@@ -352,7 +352,7 @@ def test_skipping_factorization_of_assort_by_variable_works(
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     assert "group_codes_households" not in time_series
     assert "group_codes_households" not in last_states

tests/test_time.py

@@ -100,7 +100,7 @@ def test_replace_date_with_period_in_simulation(params, initial_states, tmp_path
     result = simulate(params)
 
     time_series = result["time_series"].compute()
-    last_states = result["last_states"].compute()
+    last_states = result["last_states"]
 
     for df in [time_series, last_states]:
         assert isinstance(df, pd.DataFrame)