API Documentation¶

gcudm¶

GeoComm Unified Data Model

gcudm.base¶

The GeoAlchemy declarative base for the data model is defined in this module along with some other helpful classes.

class gcudm.base.Base(**kwargs)¶

Bases: object

The most base type

metadata = MetaData(bind=None)¶

class gcudm.base.ModelMixin[source]¶

Bases: object

This mixin includes columns and methods common to objects within the data model.

effective = Column(None, DateTime(), table=None)¶

Effective Date

This field needs a description.

Search	Display
✘	✘

Requested	Required
✔	✔

expire = Column(None, DateTime(), table=None)¶

Expiration Date

This field needs a description.

Search	Display
✘	✘

Requested	Required
✔	✔

gcUnqId = Column(None, GUID(), table=None, primary_key=True, nullable=False)¶

GeoComm ID

This field needs a description.

Search	Display
✘	✘

Requested	Required
✘	✘

classmethod geometry_type() → gcudm.geometry.GeometryTypes[source]¶

Get the geometry type defined for the model class.

Returns:	the geometry type

srcLastEd = Column(None, DateTime(), table=None)¶

Source of Last Update

This field needs a description.

Search	Display
✘	✘

Requested	Required
✘	✘

srcOfData = Column(None, String(), table=None)¶

Data Source

This field needs a description.

Search	Display
✘	✘

Requested	Required
✘	✘

srcUnqId = Column(None, String(), table=None)¶

NENA ID

This field needs a description.

Search	Display
✘	✘

Requested	Required
✔	✔

NENA:	RCL_NGUID

updateDate = Column(None, DateTime(), table=None)¶

Last Update

This field needs a description.

Search	Display
✘	✘

Requested	Required
✘	✘

uploadAuth = Column(None, String(), table=None)¶

Upload Authority

This field needs a description.

Search	Display
✘	✘

Requested	Required
✘	✘

gcudm.meta¶

This module contains metadata objects to help with inline documentation of the model.

gcudm.meta.COLUMN_META_ATTR = '__meta__'¶: the property that contains column metadata

class gcudm.meta.ColumnMeta[source]¶

Bases: tuple

Metadata for table columns.

Variables:

label (str) – a human-friendly label for the column
description (str) – a human-friendly description of the column
nena (str) – the name of the equivalent NENA field
requirement (Requirement) – defines the source data contract
usage (Usage) – defines how the data in the column is expected to be used
guaranteed (bool) – Is the column guaranteed to contain a non-empty value?
calculated (bool) – May the column’s value be generated or modified by a calculation?

calculated¶

description¶

get_enum(enum_cls: Type[Union[gcudm.meta.Requirement, gcudm.meta.Usage]]) → gcudm.meta.Requirement[source]¶

Get the current value of an attribute defined by an enumeration.

Parameters:	enum_cls – the enumeration class
Returns:	the value of the attribute

guaranteed¶

label¶

nena¶

requirement¶

usage¶

class gcudm.meta.Requirement[source]¶

Bases: enum.IntFlag

This enumeration describes contracts with source data providers.

NONE = 0¶: data for the column is neither requested nor required

REQUESTED = 1¶: data for the column is requested

REQUIRED = 3¶: data for the column is required

gcudm.meta.TABLE_META_ATTR = '__meta__'¶: the property that contains table metadata

class gcudm.meta.TableMeta[source]¶

Bases: tuple

Metadata for tables.

Variables:	label (str) – a human-friendly label for the column

label¶

class gcudm.meta.Usage[source]¶

Bases: enum.IntFlag

This enumeration describes how data may be used.

DISPLAY = 2¶: The data is displayed to users.

NONE = 0¶: The data is not used.

SEARCH = 1¶: The data is used for searching.

gcudm.meta.column(dtype: Any, meta: gcudm.meta.ColumnMeta, *args, **kwargs) → sqlalchemy.sql.schema.Column[source]¶

Create a GeoAlchemy Column annotated with metadata.

Parameters:	dtype – the GeoAlchemy column type meta – the meta data
Returns:	a GeoAlchemy `Column`

gcudm.model¶

This module contains general members to help you work with the model.

gcudm.model.IS_MODEL_CLASS = '__model_cls__'¶: signifies a model class

gcudm.model.load()[source]¶: Load the data model.

gcudm.model.model(label: str)[source]¶

Use this decorator to provide meta-data for your model class.

Parameters:	label – the friendly label for the class

gcudm.types¶

This module contains custom GeoAlchemy/SQLAlchemy types.

class gcudm.types.GUID(*args, **kwargs)[source]¶

Bases: sqlalchemy.sql.type_api.TypeDecorator

This is a Platform-independent GUID type that uses PostgreSQL’s UUID type ( and otherwise uses CHAR(32), storing as stringified hex values.

impl¶: alias of sqlalchemy.sql.sqltypes.CHAR

load_dialect_impl(dialect)[source]¶

Return a TypeEngine object corresponding to a dialect.

This is an end-user override hook that can be used to provide differing types depending on the given dialect. It is used by the TypeDecorator implementation of type_engine() to help determine what type should ultimately be returned for a given TypeDecorator.

By default returns self.impl.

process_bind_param(value, dialect)[source]¶

Receive a bound parameter value to be converted.

Subclasses override this method to return the value that should be passed along to the underlying TypeEngine object, and from there to the DBAPI execute() method.

The operation could be anything desired to perform custom behavior, such as transforming or serializing data. This could also be used as a hook for validating logic.

This operation should be designed with the reverse operation in mind, which would be the process_result_value method of this class.

Parameters:	value – Data to operate upon, of any type expected by this method in the subclass. Can be `None`. dialect – the `Dialect` in use.

process_result_value(value, dialect)[source]¶

Receive a result-row column value to be converted.

Subclasses should implement this method to operate on data fetched from the database.

Subclasses override this method to return the value that should be passed back to the application, given a value that is already processed by the underlying TypeEngine object, originally from the DBAPI cursor method fetchone() or similar.

The operation could be anything desired to perform custom behavior, such as transforming or serializing data. This could also be used as a hook for validating logic.

Parameters:	value – Data to operate upon, of any type expected by this method in the subclass. Can be `None`. dialect – the `Dialect` in use.

This operation should be designed to be reversible by the “process_bind_param” method of this class.