villebro commented on a change in pull request #8733: Replace pandas.DataFrame with PyArrow.Table for nullable int typing URL: https://github.com/apache/incubator-superset/pull/8733#discussion_r359018477
########## File path: superset/table.py ########## @@ -0,0 +1,158 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +# pylint: disable=C,R,W +""" Superset wrapper around pyarrow.Table. +""" +import logging +import re + +import numpy as np +import pandas as pd +import pyarrow as pa + + +def dedup(l, suffix="__", case_sensitive=True): + """De-duplicates a list of string by suffixing a counter + + Always returns the same number of entries as provided, and always returns + unique values. Case sensitive comparison by default. + + >>> print(','.join(dedup(['foo', 'bar', 'bar', 'bar', 'Bar']))) + foo,bar,bar__1,bar__2,Bar + >>> print( + ','.join(dedup(['foo', 'bar', 'bar', 'bar', 'Bar'], case_sensitive=False)) + ) + foo,bar,bar__1,bar__2,Bar__3 + """ + new_l = [] + seen = {} + for s in l: + s_fixed_case = s if case_sensitive else s.lower() + if s_fixed_case in seen: + seen[s_fixed_case] += 1 + s += suffix + str(seen[s_fixed_case]) + else: + seen[s_fixed_case] = 0 + new_l.append(s) + return new_l + + +class SupersetTable(object): + def __init__(self, data, cursor_description, db_engine_spec): + data = data or [] + column_names = [] + + if cursor_description: + # get deduped list of column names + column_names = dedup([col[0] for col in cursor_description]) + + # fix cursor descriptor with the deduped names + cursor_description = [ + tuple([column_name, *list(description)[1:]]) + for column_name, description in zip(column_names, cursor_description) + ] + + # put data in a 2D array so we can efficiently access each column; + array = np.array(data, dtype="object") + if array.size > 0: + data = [pa.array(array[:, i]) for i, column in enumerate(column_names)] + + # workaround for bug converting `psycopg2.tz.FixedOffsetTimezone` tzinfo values. + # related: https://issues.apache.org/jira/browse/ARROW-5248 + if data: + for i, column in enumerate(column_names): + if pa.types.is_temporal(data[i].type): + series = pd.Series(array[:, i]) + data[i] = pa.Array.from_pandas(series) + + self.table = pa.Table.from_arrays(data, names=column_names) + self._type_dict = {} + try: + # The driver may not be passing a cursor.description + self._type_dict = { + col: db_engine_spec.get_datatype(cursor_description[i][1]) + for i, col in enumerate(column_names) + if cursor_description + } + except Exception as e: + logging.exception(e) + + @classmethod + def pa_table_to_df(cls, pa_table): + return pa_table.to_pandas(integer_object_nulls=True) + + @staticmethod + def is_date(db_type_str): + return db_type_str in ("DATETIME", "TIMESTAMP") + + @classmethod + def is_id(cls, column_name): + return column_name.startswith("id") or column_name.endswith("id") Review comment: static and types? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
