Merk
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Projects a set of expressions and returns a new DataFrame.
Syntax
select(*cols: "ColumnOrName")
Parameters
| Parameter | Type | Description |
|---|---|---|
cols |
str, Column, or list | column names (string) or expressions (Column). If one of the column names is '*', that column is expanded to include all columns in the current DataFrame. |
Returns
DataFrame: A DataFrame with subset (or all) of columns.
Examples
df = spark.createDataFrame([
(2, "Alice"), (5, "Bob")], schema=["age", "name"])
df.select('*').show()
# +---+-----+
# |age| name|
# +---+-----+
# | 2|Alice|
# | 5| Bob|
# +---+-----+
df.select(df.name, (df.age + 10).alias('age')).show()
# +-----+---+
# | name|age|
# +-----+---+
# |Alice| 12|
# | Bob| 15|
# +-----+---+