溢出错误：将matlab datenum转换为python datetime时日期值超出范围

Question

我正在尝试使用以下函数将 matlab datenum 格式的 pandas 数据框列转换为 python 日期时间格式：

def datenum_to_datetime(datenum):
    """
    Convert Matlab datenum into Python datetime.
    :param datenum: Date in datenum format
    :return:        Datetime object corresponding to datenum.
    """
    days = datenum % 1
    date = datetime.fromordinal(int(datenum)) \
           + timedelta(days=days) \
           - timedelta(days=366)
 
    return date.year

值的样本

0         693726
1         693726
2         693726
3         693726
4         693726
           ...  
460718    726831
460719    726831
460720    726831
460721    726831
460722    726831
Name: dob, Length: 460723, dtype: int32

但是当我尝试应用该功能时出现以下错误。

df['dob'] = df['dob'].apply(datenum_to_datetime)

OverflowError                             Traceback (most recent call last)
<ipython-input-67-cc4fb607b497> in <module>()
----> 1 df['dob'] = df['dob'].apply(datenum_to_datetime)
      2 df.head()

1 frames
pandas/_libs/lib.pyx in pandas._libs.lib.map_infer()

<ipython-input-66-bab915eae5ff> in datenum_to_datetime(datenum)
      6     """
      7     days = datenum % 1
----> 8     date = datetime.fromordinal(int(datenum))            + timedelta(days=2)            - timedelta(days=366)
      9 
     10     return date.year

OverflowError: date value out of range

Answer 1

在Converting Matlab's datenum format to Python 之后没有找到单一的解决方案，但是这个函数可以正常工作

def datenum_to_datetime(datenum):
    """
    Convert Matlab datenum into Python datetime.
    :param datenum: Date in datenum format
    :return:        Datetime object corresponding to datenum.
    """
    origin = np.datetime64('0000-01-01', 'D') - np.timedelta64(1, 'D')
    date = datenum * np.timedelta64(1, 'D') + origin
    year = date.astype('datetime64[Y]').astype(int) + 1970
 
    return year