assembl.lib.sqla_types module

Some specialized SQLAlchemy column types

class assembl.lib.sqla_types.CaseInsensitiveWord(word)

Bases: sqlalchemy.ext.hybrid.Comparator

Hybrid value representing a lower case representation of a word.

key = 'word'

Label to apply to Query tuple results

operate(op, other)

Operate on an argument.

This is the lowest level of operation, raises NotImplementedError by default.

Overriding this on a subclass can allow common behavior to be applied to all operations. For example, overriding ColumnOperators to apply func.lower() to the left and right side:

class MyComparator(ColumnOperators):
    def operate(self, op, other):
        return op(func.lower(self), func.lower(other))

Parameters

• op – Operator callable.

• *other – the ‘other’ side of the operation. Will be a single scalar for most operations.

• **kwargs – modifiers. These may be passed by special operators such as ColumnOperators.contains().

class assembl.lib.sqla_types.EmailString(*args, **kwargs)

Bases: sqlalchemy.sql.type_api.TypeDecorator

copy(**kw)

Produce a copy of this TypeDecorator instance.

This is a shallow copy and is provided to fulfill part of the TypeEngine contract. It usually does not need to be overridden unless the user-defined TypeDecorator has local state that should be deep-copied.

impl

alias of sqlalchemy.sql.sqltypes.String

process_bind_param(value, dialect)

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.

property python_type

Return the Python type object expected to be returned by instances of this type, if known.

Basically, for those types which enforce a return type, or are known across the board to do such for all common DBAPIs (like int for example), will return that type.

If a return type is not defined, raises NotImplementedError.

Note that any type also accommodates NULL in SQL which means you can also get back None from any type in practice.

class assembl.lib.sqla_types.EmailUnicode(*args, **kwargs)

Bases: assembl.lib.sqla_types.EmailString

impl

alias of sqlalchemy.sql.sqltypes.Unicode

class assembl.lib.sqla_types.JSONType(*args, **kwargs)

Bases: sqlalchemy.sql.sqltypes.PickleType

impl

alias of sqlalchemy.sql.sqltypes.Text

class assembl.lib.sqla_types.URIRefString(*args, **kwargs)

Bases: sqlalchemy.sql.type_api.TypeDecorator

Safely coerce URIRefs to Strings.

copy(**kw)

Produce a copy of this TypeDecorator instance.

This is a shallow copy and is provided to fulfill part of the TypeEngine contract. It usually does not need to be overridden unless the user-defined TypeDecorator has local state that should be deep-copied.

impl

alias of sqlalchemy.sql.sqltypes.Unicode

process_bind_param(value, dialect)

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)

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.

property python_type

Return the Python type object expected to be returned by instances of this type, if known.

Basically, for those types which enforce a return type, or are known across the board to do such for all common DBAPIs (like int for example), will return that type.

If a return type is not defined, raises NotImplementedError.

Note that any type also accommodates NULL in SQL which means you can also get back None from any type in practice.

class assembl.lib.sqla_types.URLString(*args, **kwargs)

Bases: sqlalchemy.sql.type_api.TypeDecorator

Safely coerce URLs to Strings.

copy(**kw)

Produce a copy of this TypeDecorator instance.

This is a shallow copy and is provided to fulfill part of the TypeEngine contract. It usually does not need to be overridden unless the user-defined TypeDecorator has local state that should be deep-copied.

impl

alias of sqlalchemy.sql.sqltypes.String

process_bind_param(value, dialect)

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.

property python_type

Return the Python type object expected to be returned by instances of this type, if known.

Basically, for those types which enforce a return type, or are known across the board to do such for all common DBAPIs (like int for example), will return that type.

If a return type is not defined, raises NotImplementedError.

Note that any type also accommodates NULL in SQL which means you can also get back None from any type in practice.

class assembl.lib.sqla_types.UUID(*args, **kwargs)

Bases: sqlalchemy.sql.type_api.TypeDecorator

Adapted from: http://stackoverflow.com/questions/183042/how-can-i-use-uuids-in-sqlalchemy

copy(**kw)

Produce a copy of this TypeDecorator instance.

This is a shallow copy and is provided to fulfill part of the TypeEngine contract. It usually does not need to be overridden unless the user-defined TypeDecorator has local state that should be deep-copied.

impl

alias of sqlalchemy.dialects.postgresql.base.UUID

process_bind_param(value, dialect=None)

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=None)

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.