按类型的期望

使用 Great Expectations 的数据质量入门

Davina Moossazadeh

Data Scientist

数值型期望：聚合级

gx.expectations.ExpectColumnMeanToBeBetween(
    column="mark_price_usd", min_value=20, max_value=25
)

gx.expectations.ExpectColumnMedianToBeBetween(
    column="mark_price_usd", min_value=20, max_value=25
)

gx.expectations.ExpectColumnStdevToBeBetween(
    column="mark_price_usd", min_value=15, max_value=20
)

gx.expectations.ExpectColumnSumToBeBetween(
    column="mark_price_usd", min_value=20000, max_value=21000
)

数值型期望：行级

为行级设置取值范围期望：

gx.expectations.ExpectColumnValuesToBeBetween(
    column="star_rating", min_value=0, max_value=5
)

或有序性：

gx.expectations.ExpectColumnValuesToBeIncreasing(
    column="price_usd"
)

gx.expectations.ExpectColumnValuesToBeDecreasing(
    column="price_usd"
)

字符串期望

设置字符串期望（均为行级）：

gx.expectations.ExpectColumnValueLengthsToEqual(
    column="sku_id", value=18
)

gx.expectations.ExpectColumnValuesToMatchRegex(
    column="link", regex="^https://us.shein.com/[\w-]+"
)

regex_list = [
    "//img.ltwebstatic.com/images3_(spmp)|(pi)/202[0-4]/[0-1][0-9]/.*",
    "//sheinsz.ltwebstatic.com/she_dist/images/bg-g.*"
]

gx.expectations.ExpectColumnValuesToMatchRegexList(
    column="hero_image", regex_list=regex_list
)

字符串可解析性期望

为字符串列设置可解析性期望

日期用 ExpectColumnValuesToBeDateutilParseable()：

gx.expectations.ExpectColumnValuesToBeDateutilParseable(
    column="colour"
)

JSON 用 ExpectColumnValuesToBeJsonParseable()：

gx.expectations.ExpectColumnValuesToBeJsonParseable(
    column="colour"
)

速查表

数值型期望：

ExpectColumn<METRIC>ToBeBetween(
    column, min_value, max_value
)
# <METRIC> in {"Mean", "Median", "Stdev", "Sum"}

ExpectColumnValuesToBeBetween(
    column, min_value, max_value
)

ExpectColumnValuesToBeIncreasing(column)

ExpectColumnValuesToBeDecreasing(column)

字符串期望：

ExpectColumnValueLengthsToEqual(column, value)

ExpectColumnValuesToMatchRegex(column, regex)

ExpectColumnValuesToMatchRegexList(
    column, regex_list
)

ExpectColumnValuesToBeDateutilParseable(column)

ExpectColumnValuesToBeJsonParseable(column)

开始练习！

使用 Great Expectations 的数据质量入门