latch.registry package#

Subpackages#

latch.registry.upstream_types package

Submodules#

latch.registry.project module#

class latch.registry.project.Project(id: str)[source]#

Bases: object

Registry project (folder containing tables).

list_registry_projects() is the typical way to get a Project.

id: str#: Unique identifier.

load() → None[source]#

(Re-)populate this project instance’s cache.

Future calls to most getters will return immediately without making a network request.

Always makes a network request.

get_display_name(*, load_if_missing: Literal[True] = 'True') → str[source]#

get_display_name(*, load_if_missing: bool) → Optional[str]

Get the display name of this project.

This is an opaque string that can contain any valid Unicode data.

Display names are not unique and must never be used as identifiers. Use id instead.

Parameters: load_if_missing – If true, load() the display name if not in cache. If false, return None if not in cache.
Returns: Display name.

list_tables(*, load_if_missing: Literal[True] = 'True') → List[latch.registry.table.Table][source]#

list_tables(*, load_if_missing: bool) → Optional[List[latch.registry.table.Table]]

List Registry tables contained in this project.

Parameters: load_if_missing – If true, load() the table list if not in cache. If false, return None if not in cache.
Returns: Tables in this project.

update(*, reload_on_commit: bool = True) → Iterator[latch.registry.project.ProjectUpdate][source]#

Start an update transaction.

The transaction will commit when the context manager closes unless an error occurs.

No changes will occur until the transaction commits.

The transaction can be cancelled by running ProjectUpdate.clear() before closing the context manager.

Parameters: reload_on_commit – If true, load() this project after the transaction commits.
Returns: Context manager for the new transaction.

class latch.registry.project.ProjectUpdate(project: latch.registry.project.Project)[source]#

Bases: object

project: latch.registry.project.Project#

upsert_table(display_name: str)[source]#

Creates a table.

Not idempotent. Two calls with the same args will create two tables.

Parameters: display_name – The display name of the new table.

delete_table(id: str)[source]#

Deletes a table.

Parameters: id – The ID of the target table.

commit() → None[source]#

Commit this project update transaction.

May be called multiple times.

All pending updates are committed with one network request.

Atomic. The entire transaction either commits or fails with an exception.

clear()[source]#

Remove pending updates.

May be called to cancel any pending updates that have not been committed.

latch.registry.record module#

exception latch.registry.record.NoSuchColumnError(key: str)[source]#

Bases: KeyError

Unknown column referenced by Registry method.

Reloading the containing table might help.

key#: The unknown column key.

class latch.registry.record.Record(id: str)[source]#

Bases: object

Registry record.

list_records() is the typical way to get a Record.

id: str#: Unique identifier.

load() → None[source]#

(Re-)populate this record instance’s cache.

Future calls to most getters will return immediately without making a network request.

Always makes a network request.

get_name(*, load_if_missing: Literal[True] = 'True') → str[source]#

get_name(*, load_if_missing: bool) → Optional[str]

Get the name of this record.

Names are unique within a table. Names are not globally unique. Use id if a globally unique identifier is required.

Parameters: load_if_missing – If true, load() the name if not in cache. If false, return None if not in cache.
Returns: Name of this record.

get_columns(*, load_if_missing: Literal[True] = 'True') → Dict[str, Column][source]#

get_columns(*, load_if_missing: bool) → Optional[Dict[str, Column]]

Get the columns of this record’s table.

Parameters: load_if_missing – If true, load() the column list if not in cache. If false, return None if not in cache.
Returns: Mapping between column keys and columns.

get_values(*, load_if_missing: Literal[True] = 'True') → Dict[str, RecordValue][source]#

get_values(*, load_if_missing: bool) → Optional[Dict[str, RecordValue]]

Get this record’s values.

The resulting dictionary is shared between all calls to get_values(). Make deep copies if independent mutation is desired.

Parameters: load_if_missing – If true, load() the values if not in cache. If false, return None if not in cache.
Returns: Mapping between column keys and the corresponding value.

latch.registry.table module#

class latch.registry.table.Table(id: str)[source]#

Bases: object

Registry table. Contains records.

list_tables() is the typical way to get a Table.

id: str#: Unique identifier.

load() → None[source]#

(Re-)populate this table instance’s cache.

Future calls to most getters will return immediately without making a network request.

Always makes a network request.

get_display_name(*, load_if_missing: Literal[True] = 'True') → str[source]#

get_display_name(*, load_if_missing: bool) → Optional[str]

Get the display name of this table.

This is an opaque string that can contain any valid Unicode data.

Display names are not unique and must never be used as identifiers. Use id instead.

Parameters: load_if_missing – If true, load() the display name if not in cache. If false, return None if not in cache.
Returns: Display name.

get_columns(*, load_if_missing: Literal[True] = 'True') → Dict[str, latch.registry.types.Column][source]#

get_columns(*, load_if_missing: bool) → Optional[Dict[str, latch.registry.types.Column]]

Get the columns of this table.

Parameters: load_if_missing – If true, load() the column list if not in cache. If false, return None if not in cache.
Returns: Mapping between column keys and columns.

list_records(*, page_size: int = 100) → Iterator[Dict[str, latch.registry.record.Record]][source]#

List Registry records contained in this table.

Parameters: page_size – Maximum size of a page of records. The last page may be shorter than this value.
Yields: Pages of records. Each page is a mapping between record IDs and records.

update(*, reload_on_commit: bool = True) → Iterator[latch.registry.table.TableUpdate][source]#

Start an update transaction.

The transaction will commit when the context manager closes unless an error occurs.

No changes will occur until the transaction commits.

The transaction can be cancelled by running TableUpdate.clear() before closing the context manager.

Parameters: reload_on_commit – If true, load() this table after the transaction commits.
Returns: Context manager for the new transaction.

exception latch.registry.table.InvalidColumnTypeError(key: str, invalid_type: Union[Type[object], Type[str], Type[int], Type[float], Type[datetime.date], Type[datetime.datetime], Type[bool], Type[latch.types.file.LatchFile], Type[latch.types.directory.LatchDir], Type[latch.registry.types.StrEnum], Type[latch.registry.types.RegistryEnumDefinition], Type[latch.registry.types.LinkedRecordType], Type[List[latch.types.file.LatchFile]], Type[List[latch.types.directory.LatchDir]], Type[List[latch.registry.types.LinkedRecordType]]], msg: str)[source]#

Bases: ValueError

Failure to use an invalid column type.

key#: Identifier of the invalid column.

invalid_type#: Requested column type.

class latch.registry.table.TableUpdate(table: latch.registry.table.Table)[source]#

Bases: object

Ongoing Table update transaction.

Groups requested updates to commit everything together in one network request.

Transactions are atomic. The entire transaction either commits or fails with an exception.

table: latch.registry.table.Table#

DANGEROUSLY Update or create a record using raw values.

Values are not checked against the existing columns.

A transport error will be thrown if non-existent columns are updated.

The update will succeed if values do not match column types and future reads will produce invalid values.

Unsafe:: The value dictionary is not validated in any way. It is possible to create completely invalid record values that are not a valid Registry value of any type. Future reads will fail catastrophically when trying to parse these values.

Parameters

name – Target record name.
values – Column values that to set.

upsert_record(name: str, **values: Union[str, datetime.datetime, datetime.date, int, float, latch.types.file.LatchFile, latch.types.directory.LatchDir, None, bool, latch.registry.record.Record, List[Union[str, datetime.datetime, datetime.date, int, float, latch.types.file.LatchFile, latch.types.directory.LatchDir, None, bool, latch.registry.record.Record, List[RegistryPythonValue]]]]) → None[source]#

Update or create a record.

A transport error will be thrown if non-existent columns are updated.

It is possible that the column definitions changed since the table was last loaded and the update will be issued with values that do not match current column types. This will succeed with no error and future reads will produce invalid values.

Parameters

name – Target record name.
values – Column values to set.

delete_record(name: str) → None[source]#

Delete a record.

Parameters: name – Target record name.

upsert_column(key: str, type: Union[Type[str], Type[int], Type[float], Type[datetime.date], Type[datetime.datetime], Type[bool], Type[latch.types.file.LatchFile], Type[latch.types.directory.LatchDir], Type[latch.registry.types.StrEnum], Type[latch.registry.types.RegistryEnumDefinition], Type[latch.registry.types.LinkedRecordType], Type[List[latch.types.file.LatchFile]], Type[List[latch.types.directory.LatchDir]], Type[List[latch.registry.types.LinkedRecordType]]], *, required: bool = False)[source]#

Create a column. Support for updating columns is planned.

Parameters

key – Identifier of the new column.
type –
Type of the new column.

Only a limited set of Python types is currently supported and will be expanded over time.

latch.registry.types.RegistryPythonType represents the currently supported types.
required –
If true, records without a value for this column are considered invalid.

Note that an explicit None value is different from a missing/empty value. None is a valid value for an Optional (nullable) column marked as required.