strptime() argument 1 must be str, not Series time series convert

Question

I use datetime to read time from json, the code for single time works well,

 import datetime
 data=datetime.datetime.strptime('Apr 12, 2018', '%b %d, Y').strftime('%m/%d/%Y')

However, when I try to apply it into data frame, I have error.

 df_newtime=datetime.datetime.strptime(old_df['oldDate'],'%b %d, %Y').strftime('%m/%d/%Y')

the error is TypeError: strptime() argument 1 must be str, not Series

Answer 1

You can do it in two ways:

Method 1:

Here we pass a string to the function using map

list(map(lambda x: datetime.datetime.strptime(x,'%b %d, %Y').strftime('%m/%d/%Y'), old_df['oldDate']))

Method 2:

Here we pass a series

pd.to_datetime(old_df['oldDate'], format='%b %d, %Y')

Answer 2

old_df['oldDate'] will return the column containing the dates, which is a series.

You can solve this issue by using the .apply function in pandas to apply a function to every row of a dataframe. See here

def date_convert(date_to_convert):
     return datetime.datetime.strptime(date_to_convert, '%b %d, 
     %Y').strftime('%m/%d/%Y')

new_df['new_date'] = old_df['oldDate'].apply(date_convert)