Python `tempfile.gettempdir()` 不尊重 TMPDIR

Question

我正在使用共享 Linux 集群，并且希望我的临时目录为 /tmp/username 而不是默认的 /tmp。

根据tempfile docs 、gettempdir() 应使用$TMPDIR 环境变量来确定临时目录。

然而，事实似乎并非如此？!

$ export TMPDIR='/tmp/username' 
$ python -c "\
import os
import tempfile
print(os.environ['TMPDIR'])
print(tempfile.gettempdir())"
/tmp/username
/tmp

有什么建议吗？

Answer 1

该目录是否存在？用户可写吗？如果没有，它将无法工作，Python 将回退到其他位置。可以看到代码here ，转载于此供引用:

def _get_default_tempdir():
    """Calculate the default directory to use for temporary files.
    This routine should be called exactly once.

    We determine whether or not a candidate temp dir is usable by
    trying to create and write to a file in that directory.  If this
    is successful, the test file is deleted.  To prevent denial of
    service, the name of the test file must be randomized."""

    namer = _RandomNameSequence()
    dirlist = _candidate_tempdir_list()
    flags = _text_openflags

    for dir in dirlist:
        if dir != _os.curdir:
            dir = _os.path.normcase(_os.path.abspath(dir))
        # Try only a few names per directory.
        for seq in xrange(100):
            name = namer.next()
            filename = _os.path.join(dir, name)
            try:
                fd = _os.open(filename, flags, 0o600)
                try:
                    try:
                        with _io.open(fd, 'wb', closefd=False) as fp:
                            fp.write(b'blat')
                    finally:
                        _os.close(fd)
                finally:
                    _os.unlink(filename)
                return dir
            except (OSError, IOError) as e:
                if e.args[0] == _errno.EEXIST:
                    continue
                if (_os.name == 'nt' and e.args[0] == _errno.EACCES and
                    _os.path.isdir(dir) and _os.access(dir, _os.W_OK)):
                    # On windows, when a directory with the chosen name already
                    # exists, EACCES error code is returned instead of EEXIST.
                    continue
                break # no point trying more names in this directory
    raise IOError, (_errno.ENOENT,
                    ("No usable temporary directory found in %s" % dirlist))