robertwb commented on code in PR #30734: URL: https://github.com/apache/beam/pull/30734#discussion_r1561297296
########## sdks/python/apache_beam/yaml/yaml_join.py: ########## @@ -0,0 +1,273 @@ +# +# 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. +# + +"""This module defines the Join operation.""" +from typing import Any +from typing import Dict +from typing import List +from typing import Optional +from typing import Union + +import apache_beam as beam +from apache_beam.yaml import yaml_provider + + +def _validate_input(pcolls): + error_prefix = f'Invalid input {pcolls} specified.' + if not isinstance(pcolls, dict): + raise ValueError(f'{error_prefix} It must be a dict.') + if len(pcolls) < 2: + raise ValueError( + f'{error_prefix} There should be at least 2 inputs to join.') + + +def _validate_type(type): + error_prefix = f'Invalid value "{type}" for "type". It should be' + if not isinstance(type, dict) and not isinstance(type, str): + raise ValueError(f'{error_prefix} a dict or a str.') + if isinstance(type, dict): + error = ValueError( + f'{error_prefix} a dictionary of type [str, list[str]] ' + f'and have only one element with the key "outer".') + if len(type) != 1: + raise error + if next(iter(type)) != 'outer': + raise error + if not isinstance(type['outer'], list): + raise error + if isinstance(type, str) and type not in ('inner', 'outer', 'left', 'right'): + raise ValueError( + f'{error_prefix} ' + f'one of the following: "inner", "outer", "left", "right"') + + +def _validate_equalities(equalities, pcolls): + error_prefix = f'Invalid value "{equalities}" for "equalities".' + + valid_cols = {} + inputs = list(pcolls.keys()) + for input in inputs: + fields = set() + for field in pcolls[input].element_type._fields: + fields.add(field[0]) + valid_cols[input] = fields + + if isinstance(equalities, str): + for input in valid_cols.keys(): + if equalities not in valid_cols[input]: + raise ValueError( + f'{error_prefix} When "equalities" is a str, ' + f'it must be a field name that exists in all the specified inputs.') + equality = {input: equalities for input in inputs} + return [equality] + + if not isinstance(equalities, list): + raise ValueError(f'{error_prefix} It should be a str or a list.') + + input_edge_list = [] + for equality in equalities: + invalid_dict_error = ValueError( + f'{error_prefix} {equality} ' + f'should be a dict[str, str] containing at least 2 items.') + if not isinstance(equality, dict): + raise invalid_dict_error + if len(equality) < 2: + raise invalid_dict_error + + for input, col in equality.items(): + if input not in inputs: + raise ValueError( + f'{error_prefix} "{input}" is not a specified alias in "input"') + if col not in valid_cols[input]: + raise ValueError( + f'{error_prefix} "{col}" is not a valid field in "{input}"') + + input_edge_list.append(tuple(equality.keys())) + + if not _is_connected(input_edge_list): + raise ValueError( Review Comment: I think if the error is clear enough that's fine for now. Perhaps we could say `The provided equalities do not connect all of {inputs}.` ########## sdks/python/apache_beam/yaml/yaml_join.py: ########## @@ -0,0 +1,161 @@ +# +# 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. +# + +"""This module defines the Join operation.""" +import networkx as nx +import apache_beam as beam +from apache_beam.yaml import yaml_provider + + +def _validate_type(type, str): + error = ValueError('Invalid value for \'type\' in Join transform') + print(type) + if not isinstance(type, dict) and isinstance(type, str) != str: + return error + if isinstance(type, dict) and len(type) != 1 and next( + iter(type)) != 'outer' and not isinstance(type['outer'], + list): + return error + if isinstance(type, str) and type not in ( + 'inner', 'outer', 'left', 'right'): + return error + + +def _validate_equalities(equalities, pcoll): + error = ValueError( + 'Invalid value for \'equalities\' in Join transform') + if not isinstance(equalities, list): + return error + input_edge_list = [] + for equality in equalities: + if len(equality) != 2 and not isinstance(equality, dict): + return error + + for input, col in equality.items(): + # TODO: look for an easier way to get field names in a Pcollection obj + possible_cols = set() + for field in pcoll['f'].element_type._fields: + possible_cols.add(field[0]) + if input not in pcoll.keys() or col not in possible_cols: + return ValueError( + 'Invalid input alias or column name doesn\'t exist in the input') + + input_edge_list.append(tuple(equality.keys())) + + if not nx.is_connected(nx.Graph(input_edge_list)): + return ValueError( + 'Inputs in equalities are not all connected' + ) + + +def _parse_fields(tables, fields): + # TODO(titodo) - consider taking all validations to a preprocessing fn + output_fields = [] + named_columns = set() + for input, cols in fields.items(): + if input not in tables: + return ValueError(f'invalid input {input}') + if isinstance(cols, list): + for col in cols: + if col in named_columns: + return ValueError( + f'same field name {col} specified more than once') + output_fields.append(f'{input}.{col} AS {col}') + named_columns.add(col) + elif isinstance(cols, dict): + for k, v in cols.items(): + if k in named_columns: + return ValueError( + f'same field name {k} specified more than once') + output_fields.append(f'{input}.{v} AS {k}') + named_columns.add(k) + else: + return ValueError(f'invalid entry for fields') + for table in tables: + if table not in fields.keys(): + output_fields.append(f'{table}.*') + return output_fields + + +@beam.ptransform.ptransform_fn +def _SqlJoinTransform(pcoll, sql_transform_constructor, type, + equalities, fields=None): + _validate_type(type, str) + _validate_equalities(equalities, pcoll) + + tables = list(pcoll) + outer = [] + if isinstance(type, dict): + outer = type['outer'] + base_table = tables[0] + conditioned = {base_table} + + def generate_join_type(left, right): + if left in outer and right in outer: + return 'FULL' + if left in outer: + return 'LEFT' + if right in outer: + return 'RIGHT' + if not outer: + return type.upper() + return 'INNER' + + prev_table = tables[0] + join_conditions = {} + for i in range(1, len(tables)): + curr_table = tables[i] + join_type = generate_join_type(prev_table, curr_table) + join_conditions[curr_table] = f' {join_type} JOIN {curr_table}' + prev_table = curr_table + + for equality in equalities: + keys = list(equality) + left, right = keys[0], keys[1] + # TODO(titodo) - shorten this and reduce repitition + if left in conditioned and right in conditioned: + t = tables[max(tables.index(left), tables.index(right))] Review Comment: OK, that makes sense. -- This is an automated message from the Apache Git Service. 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