--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/query.py	Wed Dec 09 02:04:20 2020 +0000
@@ -0,0 +1,56 @@
+import json
+from typing import Tuple
+
+import click
+import pandas
+import pandasql
+from pandas import DataFrame
+
+
+def read(path: str, filetype: str, name: str) -> Tuple[str, DataFrame]:
+    if filetype == 'csv':
+        return name, pandas.read_csv(path)
+    elif filetype in ('tsv', 'tabular'):
+        return name, pandas.read_table(path)
+    elif filetype in ('h5', 'hdf'):
+        return name, pandas.read_hdf(path, name)
+    elif filetype == 'feather':
+        return name, pandas.read_feather(path)
+    elif filetype == 'parquet':
+        return name, pandas.read_parquet(path)
+    elif filetype == 'sqlite':
+        return pandas.read_sql(name, f'sqlite:///{path}')
+    else:
+        raise NotImplementedError(f'Unknown filetype {filetype}')
+
+
+def write(df: DataFrame, path: str, filetype: str, name: str) -> None:
+    if filetype == 'csv':
+        df.to_csv(path)
+    elif filetype in ('tsv', 'tabular'):
+        df.to_csv(path, sep='\t')
+    elif filetype in ('h5', 'hdf'):
+        with pandas.HDFStore(path) as file:
+            file.append(name, df, data_columns=list(df.columns))
+    elif filetype == 'feather':
+        df.to_feather(path)
+    elif filetype == 'parquet':
+        df.to_parquet(path)
+    elif filetype == 'sqlite':
+        df.to_sql(name, f'sqlite:///{path}')
+    else:
+        raise NotImplementedError(f'Unknown filetype {filetype}')
+
+
+@click.command()
+@click.argument('config', type=click.File())
+def main(config) -> None:
+    config = json.load(config)
+
+    tables = dict(read(table['path'], table['format'], table['name']) for table in config['tables'])
+    result = pandasql.sqldf(config['query'], tables)
+    write(result, config['result']['path'], config['result']['format'], config['result']['name'])
+
+
+if __name__ == '__main__':
+    main()