Aggiorna le Expectation Suite

Introduzione alla Data Quality con Great Expectations

Davina Moossazadeh

Data Scientist

Aggiungere Expectations

expectation = gx.expectations.ExpectTableColumnCountToEqual(
    value=10
)

suite = gx.ExpectationSuite(
    name="my_suite"
)

# Aggiungi l’Expectation alla Suite
suite.add_expectation(
    expectation=expectation
)

Multiple Expectation Suite

# Crea un’altra Expectation Suite
another_suite = gx.ExpectationSuite(name="my_other_suite")
# Aggiungi la stessa Expectation alla nuova Suite
another_suite.add_expectation(expectation=expectation)

Le Expectations non possono appartenere a più Suite contemporaneamente:

RuntimeError: Cannot add Expectation because it already belongs to an 
ExpectationSuite. If you want to update an existing Expectation, please call 
Expectation.save(). If you are copying this Expectation to a new ExpectationSuite, 
please copy it first (the core expectations and some others support 
copy(expectation)) and set `Expectation.id = None`.

Copiare Expectations

If you are copying this Expectation to a new ExpectationSuite, please copy it first 
(the core expectations and some others support copy(expectation)) and set 
`Expectation.id = None`.

Copia l’Expectation, imposta .id su None e aggiungila alla nuova Suite senza errori:

expectation_copy = expectation.copy()

expectation_copy.id = None

another_suite.add_expectation(
    expectation=expectation_copy
)

Verificare le Expectations

print(
    expectation_copy in another_suite.expectations
)

True

Eliminare Expectations

Aggiungi

.add_expectation()

suite.add_expectation(
    expectation=expectation
)

Elimina

.delete_expectation()

suite.delete_expectation(
    expectation=expectation
)

Regolare le Expectations

Aggiorna l’attributo .value e salva le modifiche:

expectation = gx.expectations.ExpectTableColumnCountToEqual(
    value=10
)

expectation.value = 11

expectation.save()

Assicurati che l’Expectation appartenga a una Suite, altrimenti:

RuntimeError: Expectation must be added to ExpectationSuite before it can be saved.

Aggiornare una Expectation Suite

suite = gx.ExpectationSuite(name="my_suite") 
validation_definition = gx.ValidationDefinition(
    data=batch_definition, suite=suite, name="my_validation_definition"
)

# Definisci l’Expectation
col_name_expectation = gx.expectations.ExpectColumnToExist(column="GHI")

# Aggiungi l’Expectation alla Suite
suite.add_expectation(expectation=col_name_expectation)

# Esegui la Validation Definition associata alla Suite
validation_results = validation_definition.run()

Salvare una Expectation Suite

Salva le modifiche alla Suite prima di eseguire la Validation Definition per evitare errori:

validation_results = validation_definition.run()

ResourceFreshnessAggregateError: ExpectationSuite 'my_suite' has changed since it 
has last been saved. Please update with `<SUITE_OBJECT>.save()`, then try your 
action again.

Salvare una Expectation Suite

Usa il metodo .save() per salvare la Suite ed eseguire la Validation Definition senza errori:

suite.save()

validation_results = validation_definition.run()

print(validation_results.success)

False

Promemoria rapido

Copia l’Expectation:

expectation_copy = expectation.copy()
expectation_copy.id = None

Verifica se l’Expectation è nella Suite:

expectation in suite.expectations

Elimina l’Expectation:

suite.delete_expectation(expectation)

Aggiorna il valore dell’Expectation:

expectation.value = new_value

Salva le modifiche all’Expectation:

expectation.save()

Salva le modifiche alla Expectation Suite:

suite.save()

Passons à la pratique !

Introduzione alla Data Quality con Great Expectations