pandas 将 <m8[ns] 转换为 int
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Convert <m8[ns] to int
提问by Cheng
I am using pandas and one of the column is of type <m8[ns]. I stored 'days' in it, like 5 days, 3 days, etc.
我正在使用Pandas，其中一列的类型是<m8[ns]。我在其中存储了“天”，例如 5 天、3 天等。
I want to convert this 'days' column from <m8[ns]to float64, how can I do that?
我想将此“天”列从 转换<m8[ns]为float64，我该怎么做？
回答by EdChum
The dtypeyou're seeing is the numpy dtype for datetimes, if you just want the days then use dt.dayto return you the days:
在dtype你看到的是日期时间的numpy的D型，如果你只是想在天，然后用 dt.day返回你的日子：
df['days'] = df['days'].dt.day
See this example:
看这个例子：
In [124]:
import datetime as dt
import pandas as pd
df = pd.DataFrame({'dates':pd.date_range(dt.datetime(2016,1,1), periods=10)})
df.info()
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 10 entries, 0 to 9
Data columns (total 1 columns):
dates 10 non-null datetime64[ns]
dtypes: datetime64[ns](1)
memory usage: 160.0 bytes
In [125]:
df['dates'].dtype
Out[125]:
dtype('<M8[ns]')
In [126]:
df['day'] = df['dates'].dt.day
df
Out[126]:
dates day
0 2016-01-01 1
1 2016-01-02 2
2 2016-01-03 3
3 2016-01-04 4
4 2016-01-05 5
5 2016-01-06 6
6 2016-01-07 7
7 2016-01-08 8
8 2016-01-09 9
9 2016-01-10 10
In [127]:
df.dtypes
Out[127]:
dates datetime64[ns]
day int64
dtype: object
