datetime to string with series in pandas
Question:
How should I transform from datetime
to string
? My attempt:
dates = p.to_datetime(p.Series(['20010101', '20010331']), format = '%Y%m%d')
dates.str
Answers:
There is no .str
accessor for datetimes and you can’t do .astype(str)
either.
Instead, use .dt.strftime
:
>>> series = pd.Series(['20010101', '20010331'])
>>> dates = pd.to_datetime(series, format='%Y%m%d')
>>> dates.dt.strftime('%Y-%m-%d')
0 2001-01-01
1 2001-03-31
dtype: object
See the docs on customizing date string formats here: strftime() and strptime() Behavior.
For old pandas versions <0.17.0
, one can instead can call .apply
with the Python standard library’s datetime.strftime
:
>>> dates.apply(lambda x: x.strftime('%Y-%m-%d'))
0 2001-01-01
1 2001-03-31
dtype: object
As of pandas version 0.17.0, you can format with the dt
accessor:
dates.dt.strftime('%Y-%m-%d')
There is a pandas function that can be applied to DateTime index in pandas data frame.
date = dataframe.index #date is the datetime index
date = dates.strftime('%Y-%m-%d') #this will return you a numpy array, element is string.
dstr = date.tolist() #this will make you numpy array into a list
the element inside the list:
u'1910-11-02'
You might need to replace the ‘u’.
There might be some additional arguments that I should put into the previous functions.
How should I transform from datetime
to string
? My attempt:
dates = p.to_datetime(p.Series(['20010101', '20010331']), format = '%Y%m%d')
dates.str
There is no .str
accessor for datetimes and you can’t do .astype(str)
either.
Instead, use .dt.strftime
:
>>> series = pd.Series(['20010101', '20010331'])
>>> dates = pd.to_datetime(series, format='%Y%m%d')
>>> dates.dt.strftime('%Y-%m-%d')
0 2001-01-01
1 2001-03-31
dtype: object
See the docs on customizing date string formats here: strftime() and strptime() Behavior.
For old pandas versions <0.17.0
, one can instead can call .apply
with the Python standard library’s datetime.strftime
:
>>> dates.apply(lambda x: x.strftime('%Y-%m-%d'))
0 2001-01-01
1 2001-03-31
dtype: object
As of pandas version 0.17.0, you can format with the dt
accessor:
dates.dt.strftime('%Y-%m-%d')
There is a pandas function that can be applied to DateTime index in pandas data frame.
date = dataframe.index #date is the datetime index
date = dates.strftime('%Y-%m-%d') #this will return you a numpy array, element is string.
dstr = date.tolist() #this will make you numpy array into a list
the element inside the list:
u'1910-11-02'
You might need to replace the ‘u’.
There might be some additional arguments that I should put into the previous functions.