Implement new filter util: filter_kwargs()

[ETA444]

Description:

---

Method Functionality Idea:

The filter_kwargs function is used to filter keyword arguments (kwargs) to include only those that are valid for a specified method. It operates based on a dictionary mapping methods to their valid keyword arguments.

How it operates:

Given a method name (method), a dictionary of keyword arguments (kwargs), and a dictionary mapping method names to valid keyword arguments (valid_kwargs_dict), this function filters the keyword arguments to include only those that are valid for the specified method.

Parameters:

• method : str - The name of the method for which keyword arguments need to be filtered. This method name should match a key in the valid_kwargs_dict.
• kwargs : dict - A dictionary of keyword arguments to be filtered according to the method's valid keyword arguments.
• valid_kwargs_dict : dict - A dictionary mapping method names (str) to lists of valid keyword argument names (str) for those methods. Only keyword arguments listed for a given method name will be included in the returned dictionary.

Returns:

• dict - A dictionary containing only the keyword arguments from kwargs that are valid for the specified method, according to valid_kwargs_dict.

Examples:

valid_kwargs = {'method1': ['param1', 'param2'], 'method2': ['param3']}
all_kwargs = {'param1': 10, 'param2': 20, 'param3': 30}
filtered_kwargs = filter_kwargs('method1', all_kwargs, valid_kwargs)
print(filtered_kwargs)  # Output: {'param1': 10, 'param2': 20}

Note:

This function is particularly useful in situations where a function or method accepts a wide variety of keyword arguments, and you want to ensure that only relevant keyword arguments are passed through, based on the specific method or operation being performed.

[ETA444]

Implementation Summary:

The function filter_kwargs() filters keyword arguments (kwargs) to include only those that are valid for a specified method. This is based on a dictionary mapping methods to their valid keyword arguments.

Code Breakdown:

1. Defining the Dictionary:

valid_kwargs = {
    'head': ['n'],
    'describe': ['percentiles', 'include', 'exclude'],
    'info': ['verbose', 'max_cols', 'memory_usage', 'show_counts']
}

• Purpose: The dictionary valid_kwargs maps method names to their respective valid keyword arguments.
• Methods:
  • 'head' accepts the 'n' argument.
  • 'describe' accepts the 'percentiles', 'include', and 'exclude' arguments.
  • 'info' accepts the 'verbose', 'max_cols', 'memory_usage', and 'show_counts' arguments.
• Usage: This dictionary is used to filter out irrelevant keyword arguments for the specified method.

2. Defining the Function:

def filter_kwargs(method: str, kwargs: dict, valid_kwargs_dict: dict) -> dict:

• Purpose: The function filter_kwargs filters keyword arguments (kwargs) for a specified method.
• Parameters:
  • method: The name of the method for which keyword arguments need to be filtered.
  • kwargs: A dictionary of keyword arguments to be filtered.
  • valid_kwargs_dict: A dictionary mapping method names to their valid keyword arguments.

3. Filtering Keyword Arguments:

    return {k: v for k, v in kwargs.items() if k in valid_kwargs_dict.get(method, [])}

• Explanation: This line returns a dictionary containing only the keyword arguments from kwargs that are valid for the specified method, according to valid_kwargs_dict.
• Logic:
  • The comprehension iterates over the kwargs items (k and v).
  • It checks if k (the keyword argument name) is in the list of valid arguments for the specified method.
  • The list of valid arguments for the method is fetched using valid_kwargs_dict.get(method, []).
  • The resulting dictionary contains only the valid keyword arguments.

See the Full Function:

The full implementation can be found in the datasafari repository.