Useful python snippets

scripts.md

Note: Modify and use as needed. Suggestions for improvements are welcome!

Parameter validator - useful to validate parameters for any api/function etc.

""" Usage:
from uuid import UUID
print(check_mandatory_params(
    {"score": 7.5, "id": "e76cbfa0-06e6-4ad9-8209-3ae786cf344d", "name": "John" },
    [
        ("score", float),
        ("id", UUID),
        ("name", str),
        ("status", lambda x: x in ["resolved", "pending"], False, "Status needs to be one of 'resolved', 'pending'"),
        ("age", lambda item: isinstance(item, int) and item >= 18, False, "Applicant must be of legal age")
    ],
))

>> {"success": True}

print(check_mandatory_params(
    {"id": "e76cbfa0-06e6-4ad9-8209-3ae786cf344d", "name": "John" },
    [
        ("score", float, True),
        ("id", UUID),
        ("name", str),
        ("status", lambda x: x in ["resolved", "pending"], False, "Status needs to be one of 'resolved', 'pending'"),
        ("age", lambda item: isinstance(item, int) and item >= 18, False, "Applicant must be of legal age")
    ]
))

>> {'success': False, 'message': 'score is missing'}
"""
def check_mandatory_params(
    params: Dict[str, Any],
    mandatory_attributes: List[
        Union[Tuple[str, type], Tuple[str, type, bool], Tuple[str, type, bool, str]]
    ] = [],
) -> Dict[str, Any]:
    for attr in mandatory_attributes:
        attr_name = attr[0]
        attr_type = attr[1]
        is_mandatory = attr[2] if len(attr) > 2 else True
        error_msg = attr[3] if len(attr) > 3 else None

        if is_mandatory and attr_name not in params:
            return {"success": False, "message": f"{attr_name} is missing"}

        if attr_name in params:
            value = params[attr_name]
            if callable(attr_type) and attr_type.__name__ == "<lambda>":
                if not attr_type(value):
                    return {
                        "success": False,
                        "message": error_msg
                        or f"Invalid data format for '{attr_name}'",
                    }
            elif not isinstance(value, attr_type):
                return {
                    "success": False,
                    "message": error_msg
                    or f"{attr_name} is not of type {attr_type.__name__}",
                }
    return {"success": True}

UUID Validator

import uuid
def is_valid_uuid(value):
    try:
        uuid.UUID(str(value))
        return True
    except Exception:
        return False

Check for presence of nested attributes using . object notation

def dotsplitgen(string):
    """    
    generator version of str.split(".")
    """
    buffer = ""
    for character in string:
        if character == ".":
            temp_buff = buffer + ""
            buffer = ""
            if temp_buff == "":
                continue
            yield temp_buff
            continue
        buffer+=character
    else:
        if buffer!="":
            yield buffer
    
    


def hasattr_nested(obj, path):
    """
    Check presence of nested attributes
    """
    for item in dotsplitgen(path):
        if hasattr(obj, item):
            obj = getattr(obj, item, None)
        else:
            break
    else:
        return True

    return False