def normalize(x, axis=None):
    """Normalization.
        
    Args:
        x (np.array): data
        axis (int): axis

    Returns:
        np.array: normalized data
    
    Examples:
        >>> data = np.array([1.5, 0.3, -0.8])
        >>> normalize(data)
        array([0.67647059, 0.32352941, 0.        ])
    """    
    min = x.min(axis=axis, keepdims=True)
    result = x-min
    result = result/result.sum()
    return result