ApproxQuantile
ApproxQuantile(dataset, column_list=None, quantile=0.5, filter_condition_dict=None, dataset_filter_by_data_type=None, duckdb_connection=None, decimal_places=2)
¶
Calculate quantile metrics for specified numeric columns in a dataset using DuckDB.
This function calculates the specified quantile (default: median/0.5) for numeric columns in the dataset. It can filter columns by explicitly provided column names AND/OR by data type(s). The function uses DuckDB's approx_quantile function for efficient computation.
Returns:
Type | Description |
---|---|
List[Dict[str, Union[str, float, dict, None]]]
|
List[Dict[str, Union[str, float, dict, None]]]: A list of dictionaries with the following keys: - column_name (str): Name of the analyzed column - approx_quantile_value (float): Calculated quantile value for the column - quantile (float): The quantile that was calculated (e.g., 0.5 for median) - table_name (str): Name of the analyzed table - execution_timestamp_utc (str): Timestamp of execution in UTC - filter_conditions (dict|None): Applied filter conditions if any - filtered_by_data_type (list|None): Data types used for filtering if any |
Parameters:
Name | Type | Description | Default |
---|---|---|---|
dataset
|
Any
|
Input dataset that can be either: - A DataFrame (pandas, polars) or other DuckDB-compatible data structure - A string representing an existing table name in the DuckDB connection When providing a DataFrame along with duckdb_connection, the DataFrame will be registered as a temporary table in that connection. |
required |
column_list
|
Optional[List[str]]
|
List of column names to analyze. Can be used together with dataset_filter_by_data_type. Defaults to None. |
None
|
quantile
|
float
|
The quantile to calculate (between 0 and 1). Default is 0.5 (median). |
0.5
|
filter_condition_dict
|
Optional[Dict[str, Union[str, int, float]]]
|
Dictionary of filter conditions to apply before calculating quantiles. Format: {'column_name': value}. Supports string, integer, and float values. Example: {'category': 'electronics', 'price': 100} Defaults to None. |
None
|
dataset_filter_by_data_type
|
Optional[List[str]]
|
Data type(s) to filter columns. Can be used together with column_list. Only numeric types are valid for quantile calculation. Example: ['INTEGER', 'DOUBLE'] Defaults to None. |
None
|
duckdb_connection
|
Optional[DuckDBPyConnection]
|
Existing DuckDB connection. If None, a new connection will be created and closed after execution. Can be used with either a table name string or a DataFrame input. Defaults to None. |
None
|
decimal_places
|
int
|
Number of decimal places to round the quantile values. Defaults to 2. |
2
|
Source code in src/whistlingduck/analyzers/ApproxQuantile.py
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