故事： 该脚本之前已用于将两个特定的csv文件合并为一个。 这些csv具有相同的标头，并用于提供回归。
现在有两个带有新标题的新csv文件可用，现在出现此错误。
我需要开始更改吗？我查看了所请求的csv，并且始终带有“开始时间”，其值（例如12323090等）。
这些值在该函数中不再起作用了吗？
调试器运行结果
Traceback (most recent call last):
File "C:\Program Files\JetBrains\PyCharm Community Edition
2017.3.4\helpers\pydev\pydevd.py", line 1668, in <module>
main()
File "C:\Program Files\JetBrains\PyCharm Community Edition
2017.3.4\helpers\pydev\pydevd.py", line 1662, in main
globals = debugger.run(setup['file'], None, None, is_module)
File "C:\Program Files\JetBrains\PyCharm Community Edition
2017.3.4\helpers\pydev\pydevd.py", line 1072, in run
pydev_imports.execfile(file, globals, locals) # execute the script
文件 “ D：/Sandbox/TD_Excel_ExpanderScript/EBA_ENDU_REG_SCR/end_regr_test_original.py”，
line 251, in <module>
ref_ev['Start Time Rel']=ref_ev['Start Time'].apply(lambda x: str(datetime.timedelta(seconds=x/1e6)))
File "C:\Python27_64\lib\site-packages\pandas\core\series.py", line 2294, in
apply mapped = lib.map_infer(values, f, convert=convert_dtype)
File "pandas\src\inference.pyx", line 1207, in pandas.lib.map_infer
(pandas\lib.c:66124)
文件 “ D：/Sandbox/TD_Excel_ExpanderScript/EBA_ENDU_REG_SCR/end_regr_test_original.py”，
line 251, in <lambda>
ref_ev['Start Time Rel']=ref_ev['Start Time'].apply(lambda x: str(datetime.timedelta(seconds=x/1e6)))
ValueError: cannot convert float NaN to integer