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Version: Python

max_by

max_by returns the maximum value for each group. Null values are ignored.

Syntax

table.maxBy(by: Union[str, list[str]]) -> Table

Parameters

ParameterTypeDescription
by optionalUnion[str, list[str]]

The column(s) by which to group data.

  • [] returns the maximum value for each column in the table (default).
  • ["X"] will output the maximum value of each group in column X.
  • ["X", "Y"] will output the maximum value of each group designated from the X and Y columns.

Returns

A new table containing the maximum value for each group.

Examples

In this example, max_by returns the maximum value for each column.

from deephaven import new_table

from deephaven.column import string_col, int_col

source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["M", "N", "O", "N", "P", "M", "O", "P", "M"]),
int_col("Number", [55, 76, 20, 130, 230, 50, 73, 137, 214]),
]
)

result = source.max_by()

In this example, max_by returns the maximum value, as grouped by X.

from deephaven import new_table
from deephaven.column import string_col, int_col

source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["M", "N", "O", "N", "P", "M", "O", "P", "M"]),
int_col("Number", [55, 76, 20, 130, 230, 50, 73, 137, 214]),
]
)

result = source.max_by(by=["X"])

In this example, max_by returns the maximum value, as grouped by X and Y.

from deephaven import new_table
from deephaven.column import string_col, int_col

source = new_table(
[
string_col("X", ["A", "B", "A", "C", "B", "A", "B", "B", "C"]),
string_col("Y", ["M", "N", "O", "N", "P", "M", "O", "P", "M"]),
int_col("Number", [55, 76, 20, 130, 230, 50, 73, 137, 214]),
]
)

result = source.max_by(by=["X", "Y"])