In-memory HWM Store (ephemeral)#

class etl_entities.hwm_store.memory_hwm_store.MemoryHWMStore#

In-memory local store for HWM values.

Note

This class should be used in tests only, because all saved HWM values will be deleted after exiting the context

Examples

Methods

`clear`()	Clears all stored HWM values.
`get_hwm`(name)	Get HWM by name from HWM store.
`set_hwm`(hwm)	Save HWM object to HWM Store.

__enter__()#

HWM store context manager.

Enter this context to use this HWM store instance as current one (instead default).

Examples

with hwm_store:
    db_reader.run()

clear() → None#: Clears all stored HWM values.

get_hwm(name: str) → HWM | None#

Get HWM by name from HWM store.

Parameters:

namestr: HWM name

Returns:

HWM object, if it exists in HWM store, or None

Examples

from etl_entities.hwm import ColumnIntHWM

# just to generate name using HWM parts
empty_hwm = ColumnIntHWM(column=..., name=..., ...)
real_hwm = hwm_store.get_hwm(empty_hwm.name)

set_hwm(hwm: HWM) → None#

Save HWM object to HWM Store.

Parameters:

hwmetl_entities.hwm.HWM: HWM object

Returns:

HWM location, like URL of file path.

Examples

from etl_entities.hwm import ColumnIntHWM

hwm = ColumnIntHWM(value=..., column=..., name=...)
hwm_location = hwm_store.set_hwm(hwm)