如何在多个if条件中添加错误消息

class ValidationError(Exception):
    """自定义验证错误类"""
    pass

def validate_user_input(input_data):
    if not input_data.get('name'):
        raise ValidationError("Name is required.")
    if not input_data.get('age'):
        raise ValidationError("Age is required.")
    if not isinstance(input_data.get('age'), int):
        raise ValidationError("Age must be an integer.")
    if input_data.get('age') < 0:
        raise ValidationError("Age cannot be negative.")

try:
    user_input = {
        'name': '',
        'age': -5
    }
    validate_user_input(user_input)
except ValidationError as e:
    print(f"Validation Error: {e}")