read_file()

Read a Validate object from disk that was previously saved with write_file().

Usage

Source

read_file(filepath)

This function loads a validation object that was previously serialized to disk using the write_file() function. The validation object will be restored with all its validation results, metadata, and optionally the source data (if it was saved with keep_tbl=True).

Warning

The read_file() function is currently experimental. Please report any issues you encounter in the Pointblank issue tracker.

Parameters

filepath: str | Path

The path to the saved validation file. Can be a string or Path object.

Returns

Validate

The restored validation object with all its original state, validation results, and metadata.

Examples

Let’s first save a validation object to disk with write_file(). We’ll use a temporary directory here, and keep_tbl=True saves the target table along with the validation results:

import pointblank as pb
import os
import tempfile

validation = (
    pb.Validate(data=pb.load_dataset("small_table"), tbl_name="small_table")
    .col_vals_gt(columns="d", value=1000)
    .col_vals_not_null(columns="c")
    .interrogate()
)

save_dir = tempfile.mkdtemp()
pb.write_file(validation, "my_validation", path=save_dir, keep_tbl=True, quiet=True)

Now we can load the validation object from disk with read_file(). The filename can be given without its extension, in which case read_file() looks for "my_validation.pkl":

restored = pb.read_file(os.path.join(save_dir, "my_validation"))

restored

		STEP	COLUMNS	VALUES	TBL	EVAL	UNITS	PASS	FAIL	W	E	C	EXT
#4CA64C66	1	col_vals_gt()	d	1000		✓	13	7 0.54	6 0.46	—	—	—	—
#4CA64C66	2	col_vals_not_null()	c	—		✓	13	11 0.85	2 0.15	—	—	—	—

The restored object has the same results as the original: the first step has 6 failing test units and the second has 2. The loaded validation object retains all its functionality, so we can, for example, get the rows that failed any step (since the target table was saved):

pb.preview(restored.get_sundered_data(type="fail"))

PolarsRows8Columns8
	date_time Datetime	date Date	a Int64	b String	c Int64	d Float64	e Boolean	f String
1	2016-01-06 17:23:00	2016-01-06	2	5-jdo-903	None	3892.4	False	mid
2	2016-01-09 12:36:00	2016-01-09	8	3-ldm-038	7	283.94	True	low
3	2016-01-15 18:46:00	2016-01-15	7	1-knw-093	3	843.34	True	high
4	2016-01-20 04:30:00	2016-01-20	3	5-bce-642	9	837.93	False	high
5	2016-01-20 04:30:00	2016-01-20	3	5-bce-642	9	837.93	False	high
6	2016-01-26 20:07:00	2016-01-26	4	2-dmx-010	7	833.98	True	low
7	2016-01-28 02:51:00	2016-01-28	2	7-dmx-010	8	108.34	False	low
8	2016-01-30 11:23:00	2016-01-30	1	3-dka-303	None	2230.09	True	high

These are the 8 rows of small_table that failed at least one of the two steps. Without keep_tbl=True in write_file(), the table wouldn’t be saved and methods that need the data, like get_sundered_data(), wouldn’t be available after loading.

See Also

write_file()

Save a validation object to disk for later retrieval with read_file().