更新期望套件

使用 Great Expectations 的数据质量入门

Davina Moossazadeh

Data Scientist

添加期望

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

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

# 将期望添加到套件
suite.add_expectation(
    expectation=expectation
)

多个期望套件

# 创建另一个期望套件
another_suite = gx.ExpectationSuite(name="my_other_suite")
# 将同一期望添加到新套件
another_suite.add_expectation(expectation=expectation)

期望不能同时属于多个套件：

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`.

复制期望

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`.

将期望复制，设置其 .id 为 None，并无错误地添加到新套件：

expectation_copy = expectation.copy()

expectation_copy.id = None

another_suite.add_expectation(
    expectation=expectation_copy
)

检查期望

print(
    expectation_copy in another_suite.expectations
)

True

删除期望

添加

.add_expectation()

suite.add_expectation(
    expectation=expectation
)

删除

.delete_expectation()

suite.delete_expectation(
    expectation=expectation
)

调整期望

更新 .value 属性并保存更改：

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

expectation.value = 11

expectation.save()

确保该期望隶属于某个套件，否则：

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

更新期望套件

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

# 定义期望
col_name_expectation = gx.expectations.ExpectColumnToExist(column="GHI")

# 将期望添加到套件
suite.add_expectation(expectation=col_name_expectation)

# 运行与套件关联的验证定义
validation_results = validation_definition.run()

保存期望套件

在运行验证定义前保存套件更改，以避免错误：

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.

保存期望套件

使用 .save() 保存套件，然后无错误地运行验证定义：

suite.save()

validation_results = validation_definition.run()

print(validation_results.success)

False

速查表

复制期望：

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

检查期望是否在套件中：

expectation in suite.expectations

删除期望：

suite.delete_expectation(expectation)

更新期望的值：

expectation.value = new_value

保存期望的更改：

expectation.save()

保存期望套件的更改：

suite.save()

Passons à la pratique !

使用 Great Expectations 的数据质量入门