Server: add PANDAS_DTYPES to model.py

Author: dshemetov

src/server/endpoints/covidcast_utils/model.py

@@ -9,6 +9,28 @@
 from ..._params import SourceSignalPair
 
 
+PANDAS_DTYPES = {
+    "source": str,
+    "signal": str,
+    "time_type": str,
+    "time_value": "Int64",
+    "geo_type": str,
+    "geo_value": str,
+    "value": float,
+    "stderr": float,
+    "sample_size": float,
+    "missing_value": "Int8",
+    "missing_stderr": "Int8",
+    "missing_sample_size": "Int8",
+    "issue": "Int64",
+    "lag": "Int64",
+    "id": "Int64",
+    "direction": "Int8",
+    "direction_updated_timestamp": "Int64",
+    "value_updated_timestamp": "Int64",
+}
+
+
 class HighValuesAre(str, Enum):
     bad = "bad"
     good = "good"