Voorwaardelijke expressies maken
Data transformatie met Polars
Liam Brannigan
Data Scientist & Polars Contributor
Indelen op beoordelingskwaliteit
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 |
- Taak: identificeer hoog beoordeelde restaurants
Indelen op beoordelingskwaliteit
ratings.with_columns(
)
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when( )
)
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when(pl.col("rating") == 5)
)
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when(pl.col("rating") == 5).then(pl.lit("Hoog beoordeeld"))
)
$$
$$
- Gebruik
pl.lit()om een letterlijke waarde door te geven, geen kolomnaam
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when(pl.col("rating") == 5).then(pl.lit("Hoog beoordeeld"))
.otherwise(pl.lit("Verbetering nodig"))
)
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when(pl.col("rating") == 5).then(pl.lit("Hoog beoordeeld"))
.otherwise(pl.lit("Verbetering nodig")).alias("quality")
)
Indelen op beoordelingskwaliteit
ratings.with_columns(
pl.when(pl.col("rating") == 5).then(pl.lit("Hoog beoordeeld"))
.otherwise(pl.lit("Verbetering nodig")).alias("quality")
)
shape: (5, 6)
| business | location | type | rating | capacity | quality |
| --- | --- | --- | --- | --- | --- |
| str | str | str | i64 | i64 | str |
|------------------|-----------------|------------|--------|----------|--------------------|
| 7burgers | Wakey Wakey | restaurant | 5 | 55 | Hoog beoordeeld |
| Bang Bang Burger | Forest Rd. | restaurant | 4 | 55 | Verbetering nodig |
| ... | ... | ... | ... | ... | ... |
Indelen op locatiegrootte
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 |
- Taak: filter restaurants op capaciteit
Indelen op locatiegrootte
ratings.with_columns(
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100)
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100).then(pl.lit("Groot"))
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100).then(pl.lit("Groot"))
.when(pl.col("capacity") >= 20)
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100).then(pl.lit("Groot"))
.when(pl.col("capacity") >= 20).then(pl.lit("Middel"))
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100).then(pl.lit("Groot"))
.when(pl.col("capacity") >= 20).then(pl.lit("Middel"))
.otherwise(pl.lit("Klein"))
)
Indelen op locatiegrootte
ratings.with_columns(
pl.when(pl.col("capacity") > 100).then(pl.lit("Groot"))
.when(pl.col("capacity") >= 20).then(pl.lit("Middel"))
.otherwise(pl.lit("Klein")).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 | Middel |
| Costa Coffee | The Moorgate | takeaway | 3 | 0 | Klein |
| The Queens Head | Denman St. | bar | 5 | 187 | Groot |
Bedrijfstypen standaardiseren
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 |
- Taak: standaardiseer de kolom
type
Bedrijfstypen standaardiseren
ratings.with_columns(
pl.col("type")
)
Bedrijfstypen standaardiseren
ratings.with_columns(
pl.col("type").replace( )
)
Bedrijfstypen standaardiseren
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 |
Laten we oefenen!
Data transformatie met Polars
