Python 如何将 numpy datetime64 转换为 datetime
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How to convert numpy datetime64 into datetime
提问by user6396
I basically face the same problem posted here:Converting between datetime, Timestamp and datetime64
我基本上面临这里发布的相同问题：Converting between datetime, Timestamp and datetime64
but I couldn't find satisfying answer from it, my question how to extract datetime from numpy.datetime64 type:
但我无法从中找到令人满意的答案，我的问题是如何从 numpy.datetime64 类型中提取日期时间：
if I try:
如果我尝试：
np.datetime64('2012-06-18T02:00:05.453000000-0400').astype(datetime.datetime)
it gave me: 1339999205453000000L
它给了我：1339999205453000000L
my current solution is convert datetime64 into a string and then turn to datetime again. but it seems quite a silly method.
我目前的解决方案是将 datetime64 转换为字符串，然后再次转换为 datetime。但这似乎是一种很愚蠢的方法。
采纳答案by hpaulj
Borrowing from Converting between datetime, Timestamp and datetime64
In [220]: x
Out[220]: numpy.datetime64('2012-06-17T23:00:05.453000000-0700')
In [221]: datetime.datetime.utcfromtimestamp(x.tolist()/1e9)
Out[221]: datetime.datetime(2012, 6, 18, 6, 0, 5, 452999)
Accounting for timezones I think that's right. Looks rather clunky though.
考虑到时区，我认为这是正确的。不过看起来比较笨重。
astype('O') is better (I think) thantolist())`:
astype('O') is better (I think) thantolist())`：
In [294]: datetime.datetime.utcfromtimestamp(x.astype('O')/1e9)
Out[294]: datetime.datetime(2012, 6, 18, 6, 0, 5, 452999)
or to get datetime in local:
或在本地获取日期时间：
In [295]: datetime.datetime.fromtimestamp(x.astype('O')/1e9)
But in the test_datatime.pyfile
https://github.com/numpy/numpy/blob/master/numpy/core/tests/test_datetime.py
但在test_datatime.py文件
https://github.com/numpy/numpy/blob/master/numpy/core/tests/test_datetime.py
I find some other options - first convert the general datetime64to one of the format that specifies units:
我找到了一些其他选项 - 首先将通用转换为datetime64指定单位的格式之一：
In [296]: x.astype('M8[D]').astype('O')
Out[296]: datetime.date(2012, 6, 18)
In [297]: x.astype('M8[ms]').astype('O')
Out[297]: datetime.datetime(2012, 6, 18, 6, 0, 5, 453000)
This works for arrays:
这适用于数组：
In [303]: np.array([[x,x],[x,x]],dtype='M8[ms]').astype('O')[0,1]
Out[303]: datetime.datetime(2012, 6, 18, 6, 0, 5, 453000)
回答by Jeff
Note that Timestamp IS a sub-class of datetime.datetime so the [4] will generally work
请注意，时间戳是 datetime.datetime 的子类，因此 [4] 通常会起作用
In [4]: pd.Timestamp(np.datetime64('2012-06-18T02:00:05.453000000-0400'))
Out[4]: Timestamp('2012-06-18 06:00:05.453000')
In [5]: pd.Timestamp(np.datetime64('2012-06-18T02:00:05.453000000-0400')).to_pydatetime()
Out[5]: datetime.datetime(2012, 6, 18, 6, 0, 5, 453000)
