sorted_first
agg.sorted_first
returns an aggregator that sorts a table in ascending order and then computes the first value, within an aggregation group, for each input column.
Syntax
sorted_first(order_by: str, cols: Union[str, list[str]]) > Aggregation
Parameters
Parameter  Type  Description 

order_by  str  The column to sort by. 
cols  Union[str, list[str]]  The source column(s) for the calculations.

If an aggregation does not rename the resulting column, the aggregation column will appear in the output table, not the input column. If multiple aggregations on the same column do not rename the resulting columns, an error will result, because the aggregations are trying to create multiple columns with the same name. For example, in table.agg_by([agg.sum_(cols=[“X”]), agg.avg(cols=["X"])
, both the sum and the average aggregators produce column X
, which results in an error.
Returns
An aggregator that sorts the table in ascending order and then computes the first value, within an aggregation group, for each input column.
Examples
In this example, agg.sorted_first
returns the first Y
value as sorted by Z
and grouped by X
.
from deephaven import new_table
from deephaven.column import string_col, int_col, double_col
from deephaven import agg as agg
source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["N", "O", "P", "N", "P", "N", "", "Q", "O"]),
int_col("Z", [3, 2, 1, 1, 3, 1, 4, 1, 2]),
]
)
result = source.agg_by([agg.sorted_first(order_by="Z", cols=["Y"])], by=["X"])
 source
 result
In this example, agg.sorted_first
returns the first Y
value (renamed to Z
), as sorted by Z
and grouped by X
.
from deephaven import new_table
from deephaven.column import string_col, int_col, double_col
from deephaven import agg as agg
source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["N", "O", "P", "N", "P", "N", "", "Q", "O"]),
int_col("Z", [3, 2, 1, 1, 3, 1, 4, 1, 2]),
]
)
result = source.agg_by([agg.sorted_first(order_by="Z", cols=["Z = Y"])], by=["X"])
 source
 result
In this example, agg.sorted_first
returns the first Y
string and first Z
integer, as sorted by Z
and grouped by X
.
from deephaven import new_table
from deephaven.column import string_col, int_col, double_col
from deephaven import agg as agg
source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["N", "O", "P", "N", "P", "N", "", "Q", "O"]),
int_col("Z", [3, 1, 2, 3, 1, 2, 4, 1, 2]),
]
)
result = source.agg_by([agg.sorted_first(order_by="Z", cols=["Y", "Z"])], by=["X"])
 source
 result
In this example, agg.sorted_first
returns the first Z
integer, as sorted by Z
and grouped by X
and Y
.
from deephaven import new_table
from deephaven.column import string_col, int_col, double_col
from deephaven import agg as agg
source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["N", "O", "P", "N", "P", "N", "", "Q", "O"]),
int_col("Z", [3, 2, 1, 1, 3, 1, 4, 1, 2]),
]
)
result = source.agg_by([agg.sorted_first(order_by="Z", cols=["Z"])], by=["X", "Y"])
 source
 result
In this example, agg.sorted_first
returns the first Y
string, and agg.max_
returns the maximum Z
integer, as sorted by Z
and grouped by X
.
from deephaven import new_table
from deephaven.column import string_col, int_col, double_col
from deephaven import agg as agg
source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["N", "O", "P", "N", "P", "N", "", "Q", "O"]),
int_col("Z", [3, 2, 1, 1, 3, 1, 4, 1, 2]),
]
)
result = source.agg_by(
[agg.sorted_first(order_by="Z", cols=["SortedFirstY = Y"]), agg.max_("Z")], by=["X"]
)
 source
 result