How to resolve TypeError: cannot convert the series to <type 'float'>

Question

对于特定的纪元值，时间的纪元值转换如下：

time.strftime("%H:%M:%S ", time.localtime(28000000000))  
Out[82]: '07:16:40 '

但是当我将上述方法应用于数据集中的纪元时间列时，

time.strftime("%H:%M:%S ", time.localtime(df1['d']))

我收到以下错误：

TypeError: cannot convert the series to type 'float'

我哪里错了？

df1['d']为纪元持续时间，列中数据如下：

28000000000
16000000000
33000000000
28000000000
27000000000
22000000000
26000000000
22000000000
22000000000
22000000000
46000000000

我需要纪元时间而不是 datetime 对象格式。

Answer 1

我认为需要 Series.apply 和 lambda 函数：

df1 = pd.DataFrame({'d':[28000000000,28000000000]})

df1['times'] = df1['d'].apply(lambda x: time.strftime("%H:%M:%S", time.localtime(x)))

或list comprehension:

df1['times'] = [time.strftime("%H:%M:%S", time.localtime(x)) for x in df1['d']]

print (df1)
             d     times
0  28000000000  03:46:40
1  28000000000  03:46:40

Answer 2

您可以使用map函数。

import pandas as pd
import time

df = pd.DataFrame([[28000000000, 2.5], [28100000000, 2.54]], columns=['d', 'e'])

df['time'] = df.d.map(lambda t: time.strftime("%H:%M:%S ", time.localtime(t)))
print(df)
#              d     e       time
# 0  28000000000  2.50  03:46:40 
# 1  28100000000  2.54  13:33:20

How to resolve TypeError: cannot convert the series to <type 'float'>

How to resolve TypeError: cannot convert the series to <type 'float'>

python

epoch

pandas