pandas 的datetime和datetime64 [ns]之间的比较 [英] Comparison between datetime and datetime64[ns] in pandas

问题描述

我正在编写一个检查excel文件的程序，如果今天的日期在excel文件的日期列中，我将对其进行解析

I'm writing a program that checks an excel file and if today's date is in the excel file's date column, I parse it

我正在使用:

cur_date = datetime.today()

今天的日期.我正在检查今天是否在以下列中:

for today's date. I'm checking if today is in the column with:

bool_val = cur_date in df['date'] #evaluates to false

我确实知道今天的日期在有问题的文件中.系列的dtype是datetime64 [ns]

I do know for a fact that today's date is in the file in question. The dtype of the series is datetime64[ns]

此外，我只检查日期本身，而不检查事后的时间戳，如果这很重要的话.我这样做是为了将时间戳记为00:00:00:

Also, I am only checking the date itself and not the timestamp afterwards, if that matters. I'm doing this to make the timestamp 00:00:00:

cur_date = datetime.strptime(cur_date.strftime('%Y_%m_%d'), '%Y_%m_%d')

打印后该对象的类型也是日期时间

And the type of that object after printing is datetime as well

推荐答案

您可以使用

pd.Timestamp('today')

或

pd.to_datetime('today')

但是，两者都给出了'now'的日期和时间.

But both of those give the date and time for 'now'.

尝试以下方法:

pd.Timestamp('today').floor('D')

或

pd.to_datetime('today').floor('D')

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您也可以将 datetime 对象传递给 pandas.to_datetime ，但是我喜欢其他选项mroe.

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You could have also passed the datetime object to pandas.to_datetime but I like the other option mroe.

pd.to_datetime(datetime.datetime.today()).floor('D')

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熊猫还有一个 Timedelta 对象

pd.Timestamp('now').floor('D') + pd.Timedelta(-3, unit='D')

或者您可以使用 offsets 模块

pd.Timestamp('now').floor('D') + pd.offsets.Day(-3)

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要检查成员身份，请尝试以下一种方法

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To check for membership, try one of these

cur_date in df['date'].tolist()

或

df['date'].eq(cur_date).any()

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