dianfu commented on a change in pull request #8561: [FLINK-12588][python] Add TableSchema for Python Table API. URL: https://github.com/apache/flink/pull/8561#discussion_r288498707
########## File path: flink-python/pyflink/table/table_schema.py ########## @@ -0,0 +1,236 @@ +################################################################################ +# 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. +################################################################################ +import sys + +from pyflink.java_gateway import get_gateway +from pyflink.table.types import _to_java_type, _to_python_type +from pyflink.util.utils import to_jarray + +if sys.version >= '3': + unicode = str + + +class TableSchema(object): + """ + A table schema that represents a table's structure with field names and data types. + """ + + def __init__(self, field_names=None, data_types=None, java_object=None): + if java_object is None: + gateway = get_gateway() + j_field_names = to_jarray(gateway.jvm.String, field_names) + j_data_types = to_jarray(gateway.jvm.TypeInformation, + [_to_java_type(item) for item in data_types]) + self._j_table_schema = gateway.jvm.TableSchema(j_field_names, j_data_types) + else: + self._j_table_schema = java_object + + def copy(self): + """ + Returns a deep copy of the table schema. + + :return: A deep copy of the table schema. + """ + return TableSchema(java_object=self._j_table_schema.copy()) + + def get_field_types(self): + """ + Returns all field data types as an array. + + .. note:: + Deprecated. + Use :func:`pyflink.table.table_schema.TableSchema.get_field_data_types` instead. + + + :return: A list of all field data types. + """ + return [_to_python_type(item) for item in self._j_table_schema.getFieldTypes()] + + def get_field_data_types(self): + """ + Returns all field data types as an array. + + :return: A list of all field data types. + """ + return [_to_python_type(item) for item in self._j_table_schema.getFieldDataTypes()] + + def get_field_data_type(self, field): + """ + Returns the specified data type for the given field index or field name. + + :param field: The index of the field or the name of the field. + :return: The specified data type. + """ + if not isinstance(field, (int, str, unicode)): + raise TypeError("not supported data type: %s" % type(field)) + optional_result = self._j_table_schema.getFieldDataType(field) + if optional_result.isPresent(): + return _to_python_type(optional_result.get()) + else: + return None + + def get_field_type(self, field): + """ + Returns the specified data type for the given field index or field name. + + .. note:: + Deprecated. + Use :func:`pyflink.table.table_schema.TableSchema.get_field_data_type` instead. + + :param field: The index of the field or the name of the field. + :return: The specified data type. + """ + if not isinstance(field, (int, str, unicode)): + raise TypeError("not supported data type: %s" % type(field)) + optional_result = self._j_table_schema.getFieldType(field) + if optional_result.isPresent(): + return _to_python_type(optional_result.get()) + else: + return None + + def get_field_count(self): + """ + Returns the number of fields. + + :return: The number of fields. + """ + return self._j_table_schema.getFieldCount() + + def get_field_names(self): + """ + Returns all field names as a list. + + :return: The list of all field names. + """ + return list(self._j_table_schema.getFieldNames()) + + def get_field_name(self, field_index): + """ + Returns the specified name for the given field index. + + :param field_index: The index of the field. + :return: The field name. + """ + optional_result = self._j_table_schema.getFieldName(field_index) + if optional_result.isPresent(): + return optional_result.get() + else: + return None + + def to_row_data_type(self): + """ + Converts a table schema into a (nested) data type describing a + :func:`pyflink.table.types.DataTypes.ROW`. + + :return: The row data type. + """ + return _to_python_type(self._j_table_schema.toRowDataType()) + + def to_row_type(self): + """ + Converts a table schema into a (nested) data type describing a + :func:`pyflink.table.types.DataTypes.ROW`. + + .. note:: + Deprecated. + Use :func:`pyflink.table.table_schema.TableSchema.to_row_data_type` instead. + + :return: The row data type. + """ + return _to_python_type(self._j_table_schema.toRowType()) + + def __repr__(self): + if self._j_table_schema is not None: + return self._j_table_schema.toString() + else: + return super(TableSchema, self).__repr__() + + def __str__(self): + if self._j_table_schema is not None: + return self._j_table_schema.toString() + else: + return super(TableSchema, self).__str__() + + def __eq__(self, other): + return isinstance(other, self.__class__) and self._j_table_schema == other._j_table_schema + + def __hash__(self): + if self._j_table_schema is not None: + return self._j_table_schema.hashCode() + else: + return super(TableSchema, self).__hash__() + + def __ne__(self, other): + return not self.__eq__(other) + + @classmethod + def from_type_info(cls, data_type): Review comment: Remove this method ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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