🚧 Restore types before saving as Parquet

check_dtypes.py

@@ -2,17 +2,7 @@ import pandas as pd
 import re
 
 
-# Fix
 mods_info = pd.read_parquet("mods_info_df.parquet")
-for c in mods_info.columns:
-    if c.endswith("-count"):
-        mods_info[c] = mods_info[c].astype('Int64')
-
-
-# Tmp to parquet
-mods_info.to_parquet("tmp.parquet")
-mods_info = pd.read_parquet("tmp.parquet")
-
 
 # Check
 EXPECTED_TYPES = {

src/mods4pandas/alto4pandas.py

@@ -19,7 +19,7 @@ import pandas as pd
 import numpy as np
 from tqdm import tqdm
 
-from .lib import TagGroup, sorted_groupby, flatten, ns, insert_into_db
+from .lib import TagGroup, convert_db_to_parquet, sorted_groupby, flatten, ns, insert_into_db
 
 
 logger = logging.getLogger('alto4pandas')
@@ -188,9 +188,8 @@ def process(alto_files: List[str], output_file: str):
                 import traceback; traceback.print_exc()
 
     # Convert the alto_info SQL to a pandas DataFrame
-    alto_info_df = pd.read_sql_query("SELECT * FROM alto_info", con, index_col="alto_file")
     logger.info('Writing DataFrame to {}'.format(output_file))
-    alto_info_df.to_parquet(output_file)
+    convert_db_to_parquet(con, "alto_info", "alto_file", output_file)
 
 
 def main():

src/mods4pandas/lib.py

@@ -355,3 +355,24 @@ def insert_into_db(con, table, d: Dict):
 def insert_into_db_multiple(con, table, ld: List[Dict]):
     for d in ld:
         insert_into_db(con, table, d)
+
+def convert_db_to_parquet(con, table, index_col, output_file):
+    df = pd.read_sql_query(f"SELECT * FROM {table}", con, index_col)
+
+    # Convert Python column type into Pandas type
+    for c in df.columns:
+        column_type = current_columns_types[table][c]
+
+        if column_type == "str":
+            continue
+        elif column_type == "int":
+            df[c] = df[c].astype("Int64")
+        elif column_type == "float64":
+            df[c] = df[c].astype("Float64")
+        elif column_type == "set":
+            # TODO WIP
+            continue
+        else:
+            raise NotImplementedError(f"Column type {column_type} not implemented yet.")
+
+    df.to_parquet(output_file)

src/mods4pandas/mods4pandas.py

@@ -18,7 +18,7 @@ import click
 import pandas as pd
 from tqdm import tqdm
 
-from .lib import sorted_groupby, TagGroup, ns, flatten, insert_into_db, insert_into_db_multiple
+from .lib import convert_db_to_parquet, sorted_groupby, TagGroup, ns, flatten, insert_into_db, insert_into_db_multiple, current_columns_types
 
 
 
@@ -457,16 +457,11 @@ def process(mets_files: List[str], output_file: str, output_page_info: str):
             except Exception as e:
                 logger.exception('Exception in {}'.format(mets_file))
 
-    # Convert the mods_info SQL to a pandas DataFrame
-    mods_info_df = pd.read_sql_query("SELECT * FROM mods_info", con, index_col="recordInfo_recordIdentifier")
     logger.info('Writing DataFrame to {}'.format(output_file))
-    mods_info_df.to_parquet(output_file)
+    convert_db_to_parquet(con, "mods_info", "recordInfo_recordIdentifier", output_file)
-
     if output_page_info:
-          # Convert page_info SQL to a pandas DataFrama
-          page_info_df = pd.read_sql_query("SELECT * FROM page_info", con_page_info, index_col=["ppn", "ID"])
           logger.info('Writing DataFrame to {}'.format(output_page_info))
-          page_info_df.to_parquet(output_page_info)
+          convert_db_to_parquet(con_page_info, "page_info", ["ppn", "ID"], output_page_info)
 
 
 def main():