deep-apply 1.0.1

Deep traverse through an object and apply a function on its values.

Deep Apply

Deep traverse through an object and apply a function on its values.

Supports the following objects:

• Dictionaries
• Lists
• Sets
• Tuples
• Pydantic models

Install

pip install deep-apply

Usage

Apply upper() on values

import deep_apply


# 1. Create your callback function. Will call upper() on strings.
def to_upper(value, **_kwargs):
    """
    To uppercase.
    """

    # Apply upper() and return the value
    if isinstance(value, str):
        return value.upper()

    return value


# 2. Your data.
data = [
    {
        "id": "pZnZMffPCpJx",
        "name": "John Doe",
        "hobbies": {
            "id": "OlVZysGsIywW",
            "sport": ["football", "tennis"],
            "music": ["singing", "guitar", "piano"],
        },
    }
]

# 3. Run apply().
data = deep_apply.apply(data=data, func=to_upper)

Result

[
  {
    "id": "PZNZMFFPCPJX",
    "name": "JOHN DOE",
    "hobbies": {
      "id": "OLVZYSGSIYWW",
      "sport": [
        "FOOTBALL",
        "TENNIS"
      ],
      "music": [
        "SINGING",
        "GUITAR",
        "PIANO"
      ]
    }
  }
]

Ignore keys

You can get the current key or the current depth from **kwargs and add a condition e.g. to skip a specific key everywhere.

def to_upper(value, **kwargs):
    """
    To uppercase.
    """

    key = kwargs.get("key")
    depth = kwargs.get("depth")

    ignore = False

    # Ignore the key/field id everywhere (dictionaries or pydantic models)
    if key == "id":
        ignore = True

    # Ignore the list of music found under hobbies
    elif depth == "hobbies:music":
        ignore = True

    # Apply upper() and return the value
    if not ignore and isinstance(value, str):
        return value.upper()

    return value

Only allow specific types

If you only want to traverse through specific object types e.g. lists and dictionaires, use the argument allowed_types.

data = deep_apply.apply(data=data, func=to_upper, allowed_types=["list", "dict"])