pandas 熊猫数据帧日期时间到时间然后到秒
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Pandas dataframe datetime to time then to seconds
提问by koger23
I have a dataframe. A column contains timestamps. I would like to remove dates and convert the time to seconds.
我有一个数据框。一列包含时间戳。我想删除日期并将时间转换为秒。
First I converted them to datetime:
首先，我将它们转换为日期时间：
In:
df_time = pd.to_datetime(df["Timestamp"])
Out:
0 2017-11-07 13:09:00
1 2017-11-07 13:11:00
2 2017-11-07 13:13:00
3 2017-11-07 13:15:00
dtype: datetime64[ns]
Then I removed dates:
然后我删除了日期：
In:
df_time = pd.Series([val.time() for val in df_time])
Out:
0 13:09:00
1 13:11:00
2 13:13:00
3 13:15:00
4 13:17:00
dtype: object
But they became objects and I did not managed to convert them to datetime-like objects to convert them into seconds. I know there are some similar threads I went trhough them.
但是它们变成了对象，我没有设法将它们转换为类似日期时间的对象以将它们转换为秒。我知道有一些类似的线程我通过它们。
I thank your help in advance.
我提前感谢您的帮助。
回答by Bharath
Since you are converting it to datetime series, simply use basic maths to get the seconds i.e
由于您要将其转换为日期时间序列，因此只需使用基本数学即可获得秒数，即
df_time = pd.to_datetime(df["Timestamp"])
(df_time.dt.hour*60+df_time.dt.minute)*60 + df_time.dt.second
0 47340
1 47460
2 47580
3 47700
Name: Timestamp, dtype: int64
回答by jezrael
I think you need timedeltas by to_timedeltawith timescreated by splitand selecting second lists by str[1], then total_secondsand last cast to int:
我认为你需要timedeltas byto_timedelta和timescreated bysplit并选择第二个lists by str[1]，然后total_seconds最后一次投射到int：
df_time = pd.to_timedelta(df["Timestamp"].str.split().str[1]).dt.total_seconds().astype(int)
print (df_time)
0 47340
1 47460
2 47580
3 47700
Name: Timestamp, dtype: int32
Detail:
细节：
print (df["Timestamp"].str.split().str[1])
0 13:09:00
1 13:11:00
2 13:13:00
3 13:15:00
Name: Timestamp, dtype: object
print (pd.to_timedelta(df["Timestamp"].str.split().str[1]))
0 13:09:00
1 13:11:00
2 13:13:00
3 13:15:00
Name: Timestamp, dtype: timedelta64[ns]
Or if need seconds form datetimes use dt.second:
或者如果需要秒表datetime使用dt.second：
df_time = pd.to_datetime(df["Timestamp"]).dt.second
print (df_time)
0 0
1 0
2 0
3 0
Name: Timestamp, dtype: int64
