from datetime import datetime


def is_empty(_str: str) -> bool:
    return len(_str.strip(" ")) == 0


def toDateTime(dt: str) -> datetime | int:
    if len(dt) == 0:
        return -1
    try:
        return datetime.strptime(dt, "%Y-%m-%d")
    except ValueError:
        return -1


def toFloat(v: str) -> float:
    if len(v) == 0:
        return -1.0
    try:
        return float(v)
    except ValueError:
        return -1.0


def toInt(v: str) -> int | None:
    if len(v) == 0:
        return None
    try:
        return int(v)
    except ValueError:
        return None