Reputation: 3713
Given the following data frame and necessary wrangling:
import pandas as pd
df=pd.DataFrame({'A':['a','b','c'],
'dates':['2015-08-31 00:00:00','2015-08-24 00:00:00','2015-08-25 00:00:00']})
df.dates=df.dates.astype(str)
df['dates'] = pd.to_datetime(df.dates.str.split(',\s*').str[0])
set(df['dates'])
I end up with:
{Timestamp('2015-08-24 00:00:00'),
Timestamp('2015-08-25 00:00:00'),
Timestamp('2015-08-31 00:00:00')}
I need to convert the time stamps back to datetime (really, just date) format.
I've tried this based on the answer to this post:
df['dates'].to_pydatetime()
But that returns:
AttributeError: 'Series' object has no attribute 'to_pydatetime'
In my real data, the data type is: <M8[ns]
Upvotes: 18
Views: 62588
Reputation: 3701
You can convert a whole Timestamp
column to an array of datetime.datetime
objects like this:
dt_array = df['dates'].dt.to_pydatetime()
# dt_array is an array of datetime.datetime objects
BUT as soon as you try to use that array to create/overwrite a pandas column it will end up as a dtype='datetime64[ns]')
. For instance, columns A
and B
below will be dtype='datetime64[ns]')
.
dt_array = df['dates'].dt.to_pydatetime()
# dt_array is an array of datetime.datetime objects
df['A'] = dt_array
# or in one line
df['B'] = df['dates'].dt.to_pydatetime()
Upvotes: 2
Reputation: 11
this worked for me. df['time'] consist of a column of timestamps
df['time'] = df['time'].apply(lambda x: datetime.datetime.fromtimestamp(x).strftime('%Y-%m-%d'))
# i.e. x is a timestamp such as 1641772800 (or in date 2022-01-10)
Upvotes: 1
Reputation: 1771
You can convert directly using apply:
df.dates = df.dates.apply(lambda x: x.date())
This makes an in-place conversion of the previous 'dates' (as a timestamp) to the truncated 'datetime' only portion
Upvotes: 9
Reputation: 61
I have a similar issue where I need to convert timestamp to datetime in numpy though, but I believe it can be apply in Pandas as well. I think using function under Pandas.Timestamp would be better to convert timestamp as below.
==============================
np1=pd.DataFrame.to_numpy(df2)
print(np1)
[[Timestamp('2019-01-31 00:00:00') 'UCHITEC' 2000 2.56 5129.54]
[Timestamp('2019-01-16 00:00:00') 'UCHITEC' 1000 2.61 2618.79]]
np2= np.asarray(np1)
Timestamp('2019-01-16 00:00:00')
np3 = pd.Timestamp.to_datetime64(np2[0][0])
np4 = pd.Timestamp.to_pydatetime(np2[1][0])
print(np3)
print(np4)
2019-01-31T00:00:00.000000000
2019-01-16 00:00:00
Upvotes: 2
Reputation: 393893
You can use dt.date
to return a datetime.date
object:
In [3]:
set(df['dates'].dt.date)
Out[3]:
{datetime.date(2015, 8, 24),
datetime.date(2015, 8, 25),
datetime.date(2015, 8, 31)}
Upvotes: 9
Reputation: 29711
If you are keen on extracting only the date from a given Timestamp
object, you can get the raw datetime.date
objects by calling the unbound Timestamp.date
method as shown:
import pandas as pd
from pandas import Timestamp, Series, date_range
start = Timestamp('2016-01-01')
stop = Timestamp('2016-01-02')
s = Series(date_range(start, stop, freq = 'H'))
print s[0]
2016-01-01 00:00:00
print s.map(Timestamp.date)[0]
2016-01-01
dtype: object
Upvotes: 1