조건식 만들기

Polars로 하는 데이터 변환

Liam Brannigan

Data Scientist & Polars Contributor

평점 품질로 분류하기

shape: (5, 5)
| business         | location        | type       | rating | capacity |
| ---              | ---             | ---        | ---    | ---      |
| str              | str             | str        | i64    | i64      |
|------------------|-----------------|------------|--------|----------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       |
| Bang Bang Burger | Forest Rd.      | restaurant | 4      | 55       |
| Costa Coffee     | City Point      | café       | 5      | 41       |
| Costa Coffee     | The Moorgate    | takeaway   | 3      | 0        |
| The Queens Head  | Denman St.      | bar        | 5      | 187      |

작업: 고평점 음식점 식별

평점 품질로 분류하기

ratings.with_columns(


)

평점 품질로 분류하기

ratings.with_columns(
    pl.when(                     )

)

평점 품질로 분류하기

ratings.with_columns(
    pl.when(pl.col("rating") == 5)

)

평점 품질로 분류하기

ratings.with_columns(
    pl.when(pl.col("rating") == 5).then(pl.lit("Highly Rated"))

)

리터럴 값은 열 이름이 아닌 pl.lit()으로 전달하십시오

평점 품질로 분류하기

ratings.with_columns(
    pl.when(pl.col("rating") == 5).then(pl.lit("Highly Rated"))
    .otherwise(pl.lit("Needs Improvement"))
)

평점 품질로 분류하기

ratings.with_columns(
    pl.when(pl.col("rating") == 5).then(pl.lit("Highly Rated"))
    .otherwise(pl.lit("Needs Improvement")).alias("quality")
)

평점 품질로 분류하기

ratings.with_columns(
    pl.when(pl.col("rating") == 5).then(pl.lit("Highly Rated"))
    .otherwise(pl.lit("Needs Improvement")).alias("quality")
)

shape: (5, 6)
| business         | location        | type       | rating | capacity | quality            |
| ---              | ---             | ---        | ---    | ---      | ---                |
| str              | str             | str        | i64    | i64      | str                |
|------------------|-----------------|------------|--------|----------|--------------------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       | Highly Rated       |
| Bang Bang Burger | Forest Rd.      | restaurant | 4      | 55       | Needs Improvement  |
| ...              | ...             | ...        | ...    | ...      | ...                |

매장 규모로 분류하기

shape: (5, 5)
| business         | location        | type       | rating | capacity |
| ---              | ---             | ---        | ---    | ---      |
| str              | str             | str        | i64    | i64      |
|------------------|-----------------|------------|--------|----------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       |
| Bang Bang Burger | Forest Rd.      | restaurant | 4      | 55       |
| Costa Coffee     | City Point      | café       | 5      | 41       |
| Costa Coffee     | The Moorgate    | takeaway   | 3      | 0        |
| The Queens Head  | Denman St.      | bar        | 5      | 187      |

작업: 수용 인원으로 음식점 필터링

매장 규모로 분류하기

ratings.with_columns(



)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100)


)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100).then(pl.lit("Large"))


)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100).then(pl.lit("Large"))
    .when(pl.col("capacity") >= 20)

)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100).then(pl.lit("Large"))
    .when(pl.col("capacity") >= 20).then(pl.lit("Medium"))

)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100).then(pl.lit("Large"))
    .when(pl.col("capacity") >= 20).then(pl.lit("Medium"))
    .otherwise(pl.lit("Small"))
)

매장 규모로 분류하기

ratings.with_columns(
    pl.when(pl.col("capacity") > 100).then(pl.lit("Large"))
    .when(pl.col("capacity") >= 20).then(pl.lit("Medium"))
    .otherwise(pl.lit("Small")).alias("venue_size")
)

shape: (3, 6)
| business         | location        | type       | rating | capacity | venue_size |
| ---              | ---             | ---        | ---    | ---      | ---        |
| str              | str             | str        | i64    | i64      | str        |
|------------------|-----------------|------------|--------|----------|------------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       | Medium     |
| Costa Coffee     | The Moorgate    | takeaway   | 3      | 0        | Small      |
| The Queens Head  | Denman St.      | bar        | 5      | 187      | Large      |

업종 표준화하기

shape: (5, 5)
| business         | location        | type       | rating | capacity |
| ---              | ---             | ---        | ---    | ---      |
| str              | str             | str        | i64    | i64      |
|------------------|-----------------|------------|--------|----------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       |
| Bang Bang Burger | Forest Rd.      | restaurant | 4      | 55       |
| Costa Coffee     | City Point      | café       | 5      | 41       |
| Costa Coffee     | The Moorgate    | takeaway   | 3      | 0        |
| The Queens Head  | Denman St.      | bar        | 5      | 187      |

작업: type 열 표준화

업종 표준화하기

ratings.with_columns(
    pl.col("type")
)

업종 표준화하기

ratings.with_columns(
    pl.col("type").replace(                    )
)

업종 표준화하기

ratings.with_columns(
    pl.col("type").replace("café", "restaurant")
)

shape: (5, 5)
| business         | location        | type       | rating | capacity |
| ---              | ---             | ---        | ---    | ---      |
| str              | str             | str        | i64    | i64      |
|------------------|-----------------|------------|--------|----------|
| 7burgers         | Wakey Wakey     | restaurant | 5      | 55       |
| Bang Bang Burger | Forest Rd.      | restaurant | 4      | 55       |
| Costa Coffee     | City Point      | restaurant | 5      | 41       |
| Costa Coffee     | The Moorgate    | takeaway   | 3      | 0        |
| The Queens Head  | Denman St.      | bar        | 5      | 187      |

Vamos praticar!

Polars로 하는 데이터 변환