def coalesce(*cols):
"""Returns the first column that is not null.
>>> cDf = sqlContext.createDataFrame([(None, None), (1, None), (None, 2)], ("a", "b"))
>>> cDf.show()
+----+----+
| a| b|
+----+----+
|null|null|
| 1|null|
|null| 2|
+----+----+
>>> cDf.select(coalesce(cDf["a"], cDf["b"])).show()
+-------------+
|Coalesce(a,b)|
+-------------+
| null|
| 1|
| 2|
+-------------+
>>> cDf.select('*', coalesce(cDf["a"], lit(0.0))).show()
+----+----+---------------+
| a| b|Coalesce(a,0.0)|
+----+----+---------------+
|null|null| 0.0|
| 1|null| 1.0|
|null| 2| 0.0|
+----+----+---------------+
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.coalesce(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def coalesce(*cols):
"""Returns the first column that is not null.
>>> cDf = sqlContext.createDataFrame([(None, None), (1, None), (None, 2)], ("a", "b"))
>>> cDf.show()
+----+----+
| a| b|
+----+----+
|null|null|
| 1|null|
|null| 2|
+----+----+
>>> cDf.select(coalesce(cDf["a"], cDf["b"])).show()
+-------------+
|Coalesce(a,b)|
+-------------+
| null|
| 1|
| 2|
+-------------+
>>> cDf.select('*', coalesce(cDf["a"], lit(0.0))).show()
+----+----+---------------+
| a| b|Coalesce(a,0.0)|
+----+----+---------------+
|null|null| 0.0|
| 1|null| 1.0|
|null| 2| 0.0|
+----+----+---------------+
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.coalesce(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def countDistinct(col, *cols):
"""Returns a new :class:`Column` for distinct count of ``col`` or ``cols``.
>>> df.agg(countDistinct(df.age, df.name).alias('c')).collect()
[Row(c=2)]
>>> df.agg(countDistinct("age", "name").alias('c')).collect()
[Row(c=2)]
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.countDistinct(_to_java_column(col), _to_seq(sc, cols, _to_java_column))
return Column(jc)
def countDistinct(col, *cols):
"""Returns a new :class:`Column` for distinct count of ``col`` or ``cols``.
>>> df.agg(countDistinct(df.age, df.name).alias('c')).collect()
[Row(c=2)]
>>> df.agg(countDistinct("age", "name").alias('c')).collect()
[Row(c=2)]
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.countDistinct(_to_java_column(col), _to_seq(sc, cols, _to_java_column))
return Column(jc)
def struct(*cols):
"""Creates a new struct column.
:param cols: list of column names (string) or list of :class:`Column` expressions
that are named or aliased.
>>> df.select(struct('age', 'name').alias("struct")).collect()
[Row(struct=Row(age=2, name=u'Alice')), Row(struct=Row(age=5, name=u'Bob'))]
>>> df.select(struct([df.age, df.name]).alias("struct")).collect()
[Row(struct=Row(age=2, name=u'Alice')), Row(struct=Row(age=5, name=u'Bob'))]
"""
sc = SparkContext._active_spark_context
if len(cols) == 1 and isinstance(cols[0], (list, set)):
cols = cols[0]
jc = sc._jvm.functions.struct(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def array(*cols):
"""Creates a new array column.
:param cols: list of column names (string) or list of :class:`Column` expressions that have
the same data type.
>>> df.select(array('age', 'age').alias("arr")).collect()
[Row(arr=[2, 2]), Row(arr=[5, 5])]
>>> df.select(array([df.age, df.age]).alias("arr")).collect()
[Row(arr=[2, 2]), Row(arr=[5, 5])]
"""
sc = SparkContext._active_spark_context
if len(cols) == 1 and isinstance(cols[0], (list, set)):
cols = cols[0]
jc = sc._jvm.functions.array(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def struct(*cols):
"""Creates a new struct column.
:param cols: list of column names (string) or list of :class:`Column` expressions
that are named or aliased.
>>> df.select(struct('age', 'name').alias("struct")).collect()
[Row(struct=Row(age=2, name=u'Alice')), Row(struct=Row(age=5, name=u'Bob'))]
>>> df.select(struct([df.age, df.name]).alias("struct")).collect()
[Row(struct=Row(age=2, name=u'Alice')), Row(struct=Row(age=5, name=u'Bob'))]
"""
sc = SparkContext._active_spark_context
if len(cols) == 1 and isinstance(cols[0], (list, set)):
cols = cols[0]
jc = sc._jvm.functions.struct(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def array(*cols):
"""Creates a new array column.
:param cols: list of column names (string) or list of :class:`Column` expressions that have
the same data type.
>>> df.select(array('age', 'age').alias("arr")).collect()
[Row(arr=[2, 2]), Row(arr=[5, 5])]
>>> df.select(array([df.age, df.age]).alias("arr")).collect()
[Row(arr=[2, 2]), Row(arr=[5, 5])]
"""
sc = SparkContext._active_spark_context
if len(cols) == 1 and isinstance(cols[0], (list, set)):
cols = cols[0]
jc = sc._jvm.functions.array(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def __call__(self, *cols):
sc = SparkContext._active_spark_context
jc = self._judf.apply(_to_seq(sc, cols, _to_java_column))
return Column(jc)
def __call__(self, *cols):
sc = SparkContext._active_spark_context
jc = self._judf.apply(_to_seq(sc, cols, _to_java_column))
return Column(jc)
