问将时代转换为日期时间- python的问题

EN

import pandas as pd 
import numpy as np 
import datetime
import time

data_all = pd.ExcelFile('testData_02.xls')
data = pd.read_excel(data_all, 'TestData') 

GPSTime = data.loc[:,'GpsUtcTime'].astype(int) # In epochs
#GPSTime = pd.to_numeric(GPSTime,errors='coerce')
print(type(GPSTime))

datetime_time = datetime.datetime.fromtimestamp(GPSTime).strftime('%c')
Time_str = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(GPSTime))

In [8]: %run NKS_combmorc
<class 'pandas.core.series.Series'>
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
~\Documents\Data\NKS_combmorc\NKS_combmorc.py in <module>
     35 #datetime_time = datetime.datetime.fromtimestamp(GPSTime).strftime('%c')
     36 #datetime_time = dates.num2date(GPSTime, tz='UTC')
---> 37 Time_str = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(GPSTime))
     38
     39

~\Anaconda3\envs\py3\lib\site-packages\pandas\core\series.py in wrapper(self)
    139         if len(self) == 1:
    140             return converter(self.iloc[0])
--> 141         raise TypeError(f"cannot convert the series to {converter}")
    142
    143     wrapper.__name__ = f"__{converter.__name__}__"

TypeError: cannot convert the series to <class 'int'>