CODEWITHSUNDEEP
pythonpandasdataframedatetime
marcowitt
marcowitt

Reputation: 13

Change value of datetime in pandas Dataframe

i want to change the value of a pandas dataframe column with datetime format. Basically i want to add always 20 seconds to a row. Im new to python/pandas so i dont know any ways to solve that issue.

Here is my code so far:

df_date = dataframe['date'] # get date column
df_date = datedf.to_frame() #convert series to df


for index, row in df_date.iterrows():
    if (index % 3 == 0):
        #minute +1 f. e. from 12:00:40 to 12:01:0

    elif (index % 3 == 1) or (index % 3 == 2):     
        # seconds + 20 
        # from 12:01:00 to 12:01:20
        # or from 12:01:20 to 12:01:40

Dataframe df_date:

original:

0  2017-03-10 01:00:00
1  2017-03-10 01:00:00
2  2017-03-10 01:00:00
3  2017-03-10 01:00:00
4  2017-03-10 01:00:00

...

expected:

0  2017-03-10 01:00:20
1  2017-03-10 01:00:40
2  2017-03-10 01:01:00
3  2017-03-10 01:00:20
4  2017-03-10 01:00:40

...

Any help on this would be appreciated!

Upvotes: 1

Views: 948

Answers (1)

jezrael
jezrael

Reputation: 862406

Add timedeltas created by np.arange multiple by 20 with to_timedelta:

td = pd.to_timedelta(np.arange(1, len(dataframe) + 1) * 20, unit='s')

Or created by timedelta_range:

td = pd.timedelta_range(0, periods=len(dataframe), freq='20s') 

dataframe['date'] = pd.to_datetime(dataframe['date']) + td
print (dataframe)
                 date
0 2017-03-10 01:00:20
1 2017-03-10 01:00:40
2 2017-03-10 01:01:00
3 2017-03-10 01:01:20
4 2017-03-10 01:01:40

Upvotes: 3

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