pandas 在 Python 中将 datetime.datetime 对象转换为自纪元以来的天数
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Convert datetime.datetime object to days since epoch in Python
提问by brittenb
I've got a pandas.Seriesobject that might look like this:
我有一个pandas.Series可能看起来像这样的对象：
import pandas as pd
myVar = pd.Series(["VLADIVOSTOK 690090", "MAHE", NaN, NaN, "VLADIVOSTOK 690090", "2000-07-01 00:00:00"])
myVar[5]is parsed as a datetime.datetimeobject when the data is read into Python via pandas. I'm assuming that converting this value to the number of days since epoch (36708) isn't difficult at all. I'm just new to Python and don't know how to do it. Thanks in advance!
myVar[5]被解析为一个datetime.datetime当所述数据经由读入Python对象pandas。我假设将此值转换为自纪元 (36708) 以来的天数根本不困难。我只是 Python 新手，不知道该怎么做。提前致谢！
采纳答案by Padraic Cunningham
myVar = pd.Series(["VLADIVOSTOK 690090", "MAHE", "NaN", "NaN", "VLADIVOSTOK 690090", "2000-07-01 00:00:00"])
myVar[5] = pd.to_datetime(myVar[5]) - pd.datetime(1970,1,1)
print(myVar)
0 VLADIVOSTOK 690090
1 MAHE
2 NaN
3 NaN
4 VLADIVOSTOK 690090
5 11139 days 00:00:00
dtype: object
回答by TigerhawkT3
I'm not sure where you're getting 36,708 days since the epoch (it's only been 16,644 days since January 1, 1970), but datetime.timedeltaobjects (used in date arithmetic) have a daysattribute:
我不确定自纪元以来的 36,708 天（自 1970 年 1 月 1 日以来只有 16,644 天），但datetime.timedelta对象（用于日期算术）有一个days属性：
>>> import datetime
>>> (datetime.datetime.utcnow() - datetime.datetime(1970,1,1)).days
16644
回答by bakhtiya
You can convert this to seconds since epoch first, then divide it out by the amount of seconds in a day (86,400 seconds in a day). Please note the integer division here - will not return a float.
您可以先将其转换为自纪元以来的秒数，然后将其除以一天中的秒数（一天中的 86,400 秒）。请注意这里的整数除法 - 不会返回浮点数。
from datetime import datetime
now = datetime.now()
seconds = now.strftime("%s") # seconds since epoch
days = int(seconds) / 86400 # days since epoch
I added the import and now as an example of a datetime object I can play with.
我添加了导入，现在作为我可以使用的日期时间对象的示例。
