将时间戳从 dataframe 列转换为日期格式

Question

The following data frame is the result of

top5 = df.nlargest(5,columns='B',keep='all')

          A      B        C          D           E      F     G     H    I
77 2013-08-17  42302  2278503  100644.38  5021507.24  72471  5729  5729  217
70 2013-08-10  42245  2016000  103374.87  4492859.82  69996  5567  5567  223
74 2013-08-14  42226  2154625   78504.31  4766845.59  71481  1727  1727  219
66 2013-08-06  42086  1871575   81608.23  4209532.51  68744  1778  1778  222
59 2013-07-30  42032  1611459   79312.12  3691785.45  65855  1701  1701  237

I would like to print only dates as my result. I've tried something like this to print only the A column:

print(top5['A'].values.tolist())

But it gives me this result:

[1376697600000000000, 1376092800000000000, 1376438400000000000, 1375747200000000000, 1375142400000000000]

But I need a result like:

[2013-08-17,2013-08-10,2013-08-14,2013-08-06,2013-07-30]

What's the way to convert this timestamp to date format?

Answer 1

Enclose the column in list().

print(list(top5['A'].astype('datetime64[ns]')))

Answer 2

to get a list of strings from a datetime column, use

import pandas as pd

# what you have is like
top5  = pd.DataFrame({'A': pd.to_datetime(['2013-08-17', '2013-08-10', '2013-08-14'])})
# note the column A is of dtype datetime

# format to string using strftime and then cast to_list():
l_A = top5['A'].dt.strftime('%Y-%m-%d').to_list()
# l_A
# ['2013-08-17', '2013-08-10', '2013-08-14']