打开现有fi时出错

Question

我遇到了一个奇怪的错误-在Python中对open()的调用开始在一个文件上持续失败，尽管该文件以前已经打开并且一直（出于我们的目的）存在。你知道吗

我已将错误缩小到以下方法：

def get_header(self):
    print "Getting header of {}".format(self.fname)
    f = open(self.fname, 'r')
    print "File opened successfully: {}".format(f)
    lines = f.readlines()
    ret = ''
    if len(lines) > self.num_dp:
        ret = lines[0]
    f.close()
    return ret

以下是服务器输出的一个片段：

jmag@ph-jmag-egse ~/icu-simulator/python $ bokeh serve fsc
2016-08-17 17:03:10,389 Starting Bokeh server version 0.12.0
2016-08-17 17:03:10,392 Starting Bokeh server on port 5006 with applications at paths ['/fsc']
2016-08-17 17:03:10,392 Starting Bokeh server with process id: 11650
Getting header of ../data/FSC_SCI_TM_20160817_162704.csv
File opened successfully: <open file '../data/FSC_SCI_TM_20160817_162704.csv', mode 'r' at 0x7fa73b571780>
Tailing ../data/FSC_SCI_TM_20160817_162704.csv...
/opt/anaconda2/lib/python2.7/site-packages/bokeh/plotting/helpers.py:322: UserWarning: BoxZoomTool,PanTool are being repeated
  warnings.warn("%s are being repeated" % ",".join(repeated_tools))
Getting header of ../data/FSC_SCI_TM_20160817_162704.csv
File opened successfully: <open file '../data/FSC_SCI_TM_20160817_162704.csv', mode 'r' at 0x7fa73b571780>
Tailing ../data/FSC_SCI_TM_20160817_162704.csv...
2016-08-17 17:03:10,768 200 GET /fsc (127.0.0.1) 208.10ms
2016-08-17 17:03:10,781 304 GET /static/css/bokeh.min.css?v=12cad2d8ad9f63966dc6553746de780f (127.0.0.1) 4.44ms
2016-08-17 17:03:10,783 304 GET /static/css/bokeh-widgets.min.css?v=522d6173498a389c7f74f0e675195da0 (127.0.0.1) 1.16ms
2016-08-17 17:03:10,784 304 GET /static/js/bokeh.min.js?v=8654bbf09300c1ff666bcae026fa9500 (127.0.0.1) 0.72ms
2016-08-17 17:03:10,786 304 GET /static/js/bokeh-widgets.min.js?v=4b0df507cbc8b1cb4f8ec960d6c9718f (127.0.0.1) 0.65ms
2016-08-17 17:03:10,787 304 GET /static/js/bokeh-compiler.min.js?v=47e1cfffd831e5c4e1e3ea0702edd89c (127.0.0.1) 0.81ms
2016-08-17 17:03:11,022 WebSocket connection opened
2016-08-17 17:03:11,022 ServerConnection created
Getting header of ../data/FSC_SCI_TM_20160817_162704.csv
Getting header of ../data/FSC_SCI_TM_20160817_162704.csv
2016-08-17 17:03:20,770 Error thrown from periodic callback: IOError(2, 'No such file or directory')
Getting header of ../data/FSC_SCI_TM_20160817_162704.csv
2016-08-17 17:03:25,771 Error thrown from periodic callback: IOError(2, 'No such file or directory')
^C
Interrupted, shutting down

在Bokeh服务器上运行strace表明对open()的调用正在返回enoont，从而触发异常。你知道吗

open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = 14
write(1, "Tailing ../data/FSC_SCI_TM_20160"..., 50) = 50
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = 14
write(1, "Getting header of ../data/FSC_SC"..., 57) = 57
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = 14
write(1, "Tailing ../data/FSC_SCI_TM_20160"..., 50) = 50
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = 14
write(1, "Getting header of ../data/FSC_SC"..., 57) = 57
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = -1 ENOENT (No such file or directory)
write(1, "Getting header of ../data/FSC_SC"..., 57) = 57
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = -1 ENOENT (No such file or directory)
write(1, "Getting header of ../data/FSC_SC"..., 57) = 57
open("../data/FSC_SCI_TM_20160817_162704.csv", O_RDONLY) = -1 ENOENT (No such file or directory)

这是我力不从心的地方。文件存在-为什么操作系统（LTS Mint）会告诉我其他情况？你知道吗