Add order_by parameter to LabelEncoder

[amontanez24]

Problem Description

As a user, it would be useful to be able to specify the type of ordering I want to use for the LabelEncoder.

Expected behavior

• Add an init parameter called order_by
• It should be a string with the following possible values:
  • None (default): Just use the order the values appear in. Same as current implementation
  • numerical_value: Order by the numerical value (ie. the numerically first number should be mapped to 1, so on and so forth)
  • alphabetical: Order strings alphabetically (ie. the alphabetically first string should be mapped to 1, so on and so forth)

Validation

• During init, if the parameter is not None, 'numerical_value' or 'alphabetical', raise the following error:
  • Error: order_by must be one of the following values: None, 'numerical_value' or 'alphabetical'
• During fit if the order_by value is 'numerical_value' but the data is not numerical, then raise the following error:
  • Error: The data must be numerical or able to be casted as a float if order_by is 'numerical_value'
• During fit, if the order_by value is 'alphabetical' but the data is not a string, raise the following error:
  • Error: The data must be of type string if order_by is 'alphabetical'