subprocess.CalledProcessError ：没有这样的文件或目录。即使文件存在

Question

tail: cannot open 'home/sourabh/sanju.txt' for reading: No such file or directory

Traceback (most recent call last):

  File "/home/sourabh/resizeWindow.py", line 23, in <module>

    line = subprocess.check_output(['tail', '-1', 'home/sourabh/sanju.txt']).split(' ')[3:]

  File "/usr/lib/python2.7/subprocess.py", line 223, in check_output

    raise CalledProcessError(retcode, cmd, output=output)

subprocess.CalledProcessError: Command '['tail', '-1', 'home/sourabh/sanju.txt']' returned non-zero exit status 1

我已经交叉检查文件是否存在，甚至故意创建了一个文件。

我的python代码中的确切行是：

line = subprocess.check_output(['tail', '-1', 'home/sourabh/sanju.txt']).split(' ')[3:]