"""Temporary files.

This module provides generic, low- and high-level interfaces for

creating temporary files and directories. All of the interfaces

provided by this module can be used without fear of race conditions

except for 'mktemp'. 'mktemp' is subject to race conditions and

should not be used; it is provided for backward compatibility only.

The default path names are returned as str. If you supply bytes as

input, all return values will be in bytes. Ex:

>>> tempfile.mkstemp()

(4, '/tmp/tmptpu9nin8')

>>> tempfile.mkdtemp(suffix=b'')

b'/tmp/tmppbi8f0hy'

This module also provides some data items to the user:

TMP_MAX - maximum number of names that will be tried before

giving up.

tempdir - If this is set to a string before the first use of

any routine from this module, it will be considered as

another candidate location to store temporary files.

"""

__all__ = [

"NamedTemporaryFile", "TemporaryFile", # high level safe interfaces

"SpooledTemporaryFile", "TemporaryDirectory",

"mkstemp", "mkdtemp", # low level safe interfaces

"mktemp", # deprecated unsafe interface

"TMP_MAX", "gettempprefix", # constants

"tempdir", "gettempdir",

"gettempprefixb", "gettempdirb",

]

# Imports.

import functools as _functools

import warnings as _warnings

import io as _io

import os as _os

import shutil as _shutil

import errno as _errno

from random import Random as _Random

import sys as _sys

import weakref as _weakref

import _thread

_allocate_lock = _thread.allocate_lock

_text_openflags = _os.O_RDWR | _os.O_CREAT | _os.O_EXCL

if hasattr(_os, 'O_NOFOLLOW'):

_text_openflags |= _os.O_NOFOLLOW

_bin_openflags = _text_openflags

if hasattr(_os, 'O_BINARY'):

_bin_openflags |= _os.O_BINARY

if hasattr(_os, 'TMP_MAX'):

TMP_MAX = _os.TMP_MAX

else:

TMP_MAX = 10000

# This variable _was_ unused for legacy reasons, see issue 10354.

# But as of 3.5 we actually use it at runtime so changing it would

# have a possibly desirable side effect... But we do not want to support

# that as an API. It is undocumented on purpose. Do not depend on this.

template = "tmp"

# Internal routines.

_once_lock = _allocate_lock()

def _exists(fn):

try:

_os.lstat(fn)

except OSError:

return False

else:

return True

def _infer_return_type(*args):

"""Look at the type of all args and divine their implied return type."""

return_type = None

for arg in args:

if arg is None:

continue

if isinstance(arg, bytes):

if return_type is str:

raise TypeError("Can't mix bytes and non-bytes in "

"path components.")

return_type = bytes

else:

if return_type is bytes:

raise TypeError("Can't mix bytes and non-bytes in "

"path components.")

return_type = str

if return_type is None:

return str # tempfile APIs return a str by default.

return return_type

def _sanitize_params(prefix, suffix, dir):

"""Common parameter processing for most APIs in this module."""

output_type = _infer_return_type(prefix, suffix, dir)

if suffix is None:

suffix = output_type()

if prefix is None:

if output_type is str:

prefix = template

else:

prefix = _os.fsencode(template)

if dir is None:

if output_type is str:

dir = gettempdir()

else:

dir = gettempdirb()

return prefix, suffix, dir, output_type

class _RandomNameSequence:

"""An instance of _RandomNameSequence generates an endless

sequence of unpredictable strings which can safely be incorporated

into file names. Each string is eight characters long. Multiple

threads can safely use the same instance at the same time.

_RandomNameSequence is an iterator."""

characters = "abcdefghijklmnopqrstuvwxyz0123456789_"

@property

def rng(self):

cur_pid = _os.getpid()

if cur_pid != getattr(self, '_rng_pid', None):

self._rng = _Random()

self._rng_pid = cur_pid

return self._rng

def __iter__(self):

return self

def __next__(self):

c = self.characters

choose = self.rng.choice

letters = [choose(c) for dummy in range(8)]

return ''.join(letters)

def _candidate_tempdir_list():

"""Generate a list of candidate temporary directories which

_get_default_tempdir will try."""

dirlist = []

# First, try the environment.

for envname in 'TMPDIR', 'TEMP', 'TMP':

dirname = _os.getenv(envname)

if dirname: dirlist.append(dirname)

# Failing that, try OS-specific locations.

if _os.name == 'nt':

dirlist.extend([ _os.path.expanduser(r'~\AppData\Local\Temp'),

_os.path.expandvars(r'%SYSTEMROOT%\Temp'),

r'c:\temp', r'c:\tmp', r'\temp', r'\tmp' ])

else:

dirlist.extend([ '/tmp', '/var/tmp', '/usr/tmp' ])

# As a last resort, the current directory.

try:

dirlist.append(_os.getcwd())

except (AttributeError, OSError):

dirlist.append(_os.curdir)

return dirlist

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()

for dir in dirlist:

if dir != _os.curdir:

dir = _os.path.abspath(dir)

# Try only a few names per directory.

for seq in range(100):

name = next(namer)

filename = _os.path.join(dir, name)

try:

fd = _os.open(filename, _bin_openflags, 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 FileExistsError:

pass

except PermissionError:

# This exception is thrown when a directory with the chosen name

# already exists on windows.

if (_os.name == 'nt' and _os.path.isdir(dir) and

_os.access(dir, _os.W_OK)):

continue

break # no point trying more names in this directory

except OSError:

break # no point trying more names in this directory

raise FileNotFoundError(_errno.ENOENT,

"No usable temporary directory found in %s" %

dirlist)

_name_sequence = None

def _get_candidate_names():

"""Common setup sequence for all user-callable interfaces."""

global _name_sequence

if _name_sequence is None:

_once_lock.acquire()

try:

if _name_sequence is None:

_name_sequence = _RandomNameSequence()

finally:

_once_lock.release()

return _name_sequence

def _mkstemp_inner(dir, pre, suf, flags, output_type):

"""Code common to mkstemp, TemporaryFile, and NamedTemporaryFile."""

names = _get_candidate_names()

if output_type is bytes:

names = map(_os.fsencode, names)

for seq in range(TMP_MAX):

name = next(names)

file = _os.path.join(dir, pre + name + suf)

_sys.audit("tempfile.mkstemp", file)

try:

fd = _os.open(file, flags, 0o600)

except FileExistsError:

continue # try again

except PermissionError:

# This exception is thrown when a directory with the chosen name

# already exists on windows.

if (_os.name == 'nt' and _os.path.isdir(dir) and

_os.access(dir, _os.W_OK)):

continue

else:

raise

return (fd, _os.path.abspath(file))

raise FileExistsError(_errno.EEXIST,

"No usable temporary file name found")

def _dont_follow_symlinks(func, path, *args):

# Pass follow_symlinks=False, unless not supported on this platform.

if func in _os.supports_follow_symlinks:

func(path, *args, follow_symlinks=False)

elif _os.name == 'nt' or not _os.path.islink(path):

func(path, *args)

def _resetperms(path):

try:

chflags = _os.chflags

except AttributeError:

pass

else:

_dont_follow_symlinks(chflags, path, 0)

_dont_follow_symlinks(_os.chmod, path, 0o700)

# User visible interfaces.

def gettempprefix():

"""The default prefix for temporary directories."""

return template

def gettempprefixb():

"""The default prefix for temporary directories as bytes."""

return _os.fsencode(gettempprefix())

tempdir = None

def gettempdir():

"""Accessor for tempfile.tempdir."""

global tempdir

if tempdir is None:

_once_lock.acquire()

try:

if tempdir is None:

tempdir = _get_default_tempdir()

finally:

_once_lock.release()

return tempdir

def gettempdirb():

"""A bytes version of tempfile.gettempdir()."""

return _os.fsencode(gettempdir())

def mkstemp(suffix=None, prefix=None, dir=None, text=False):

"""User-callable function to create and return a unique temporary

file. The return value is a pair (fd, name) where fd is the

file descriptor returned by os.open, and name is the filename.

If 'suffix' is not None, the file name will end with that suffix,

otherwise there will be no suffix.

If 'prefix' is not None, the file name will begin with that prefix,

otherwise a default prefix is used.

If 'dir' is not None, the file will be created in that directory,

otherwise a default directory is used.

If 'text' is specified and true, the file is opened in text

mode. Else (the default) the file is opened in binary mode.

If any of 'suffix', 'prefix' and 'dir' are not None, they must be the

same type. If they are bytes, the returned name will be bytes; str

otherwise.

The file is readable and writable only by the creating user ID.

If the operating system uses permission bits to indicate whether a

file is executable, the file is executable by no one. The file

descriptor is not inherited by children of this process.

Caller is responsible for deleting the file when done with it.

"""

prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)

if text:

flags = _text_openflags

else:

flags = _bin_openflags

return _mkstemp_inner(dir, prefix, suffix, flags, output_type)

def mkdtemp(suffix=None, prefix=None, dir=None):

"""User-callable function to create and return a unique temporary

directory. The return value is the pathname of the directory.

Arguments are as for mkstemp, except that the 'text' argument is

not accepted.

The directory is readable, writable, and searchable only by the

creating user.

Caller is responsible for deleting the directory when done with it.

"""

prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)

names = _get_candidate_names()

if output_type is bytes:

names = map(_os.fsencode, names)

for seq in range(TMP_MAX):

name = next(names)

file = _os.path.join(dir, prefix + name + suffix)

_sys.audit("tempfile.mkdtemp", file)

try:

_os.mkdir(file, 0o700)

except FileExistsError:

continue # try again

except PermissionError:

# This exception is thrown when a directory with the chosen name

# already exists on windows.

if (_os.name == 'nt' and _os.path.isdir(dir) and

_os.access(dir, _os.W_OK)):

continue

else:

raise

return file

raise FileExistsError(_errno.EEXIST,

"No usable temporary directory name found")

def mktemp(suffix="", prefix=template, dir=None):

"""User-callable function to return a unique temporary file name. The

file is not created.

Arguments are similar to mkstemp, except that the 'text' argument is

not accepted, and suffix=None, prefix=None and bytes file names are not

supported.

THIS FUNCTION IS UNSAFE AND SHOULD NOT BE USED. The file name may

refer to a file that did not exist at some point, but by the time

you get around to creating it, someone else may have beaten you to

the punch.

"""

## from warnings import warn as _warn

## _warn("mktemp is a potential security risk to your program",

## RuntimeWarning, stacklevel=2)

if dir is None:

dir = gettempdir()

names = _get_candidate_names()

for seq in range(TMP_MAX):

name = next(names)

file = _os.path.join(dir, prefix + name + suffix)

if not _exists(file):

return file

raise FileExistsError(_errno.EEXIST,

"No usable temporary filename found")

class _TemporaryFileCloser:

"""A separate object allowing proper closing of a temporary file's

underlying file object, without adding a __del__ method to the

temporary file."""

file = None # Set here since __del__ checks it

close_called = False

def __init__(self, file, name, delete=True):

self.file = file

self.name = name

self.delete = delete

# NT provides delete-on-close as a primitive, so we don't need

# the wrapper to do anything special. We still use it so that

# file.name is useful (i.e. not "(fdopen)") with NamedTemporaryFile.

if _os.name != 'nt':

# Cache the unlinker so we don't get spurious errors at

# shutdown when the module-level "os" is None'd out. Note

# that this must be referenced as self.unlink, because the

# name TemporaryFileWrapper may also get None'd out before

# __del__ is called.

def close(self, unlink=_os.unlink):

if not self.close_called and self.file is not None:

self.close_called = True

try:

self.file.close()

finally:

if self.delete:

unlink(self.name)

# Need to ensure the file is deleted on __del__

def __del__(self):

self.close()

else:

def close(self):

if not self.close_called:

self.close_called = True

self.file.close()

class _TemporaryFileWrapper:

"""Temporary file wrapper

This class provides a wrapper around files opened for

temporary use. In particular, it seeks to automatically

remove the file when it is no longer needed.

"""

def __init__(self, file, name, delete=True):

self.file = file

self.name = name

self.delete = delete

self._closer = _TemporaryFileCloser(file, name, delete)

def __getattr__(self, name):

# Attribute lookups are delegated to the underlying file

# and cached for non-numeric results

# (i.e. methods are cached, closed and friends are not)

file = self.__dict__['file']

a = getattr(file, name)

if hasattr(a, '__call__'):

func = a

@_functools.wraps(func)

def func_wrapper(*args, **kwargs):

return func(*args, **kwargs)

# Avoid closing the file as long as the wrapper is alive,

# see issue #18879.

func_wrapper._closer = self._closer

a = func_wrapper

if not isinstance(a, int):

setattr(self, name, a)

return a

# The underlying __enter__ method returns the wrong object

# (self.file) so override it to return the wrapper

def __enter__(self):

self.file.__enter__()

return self

# Need to trap __exit__ as well to ensure the file gets

# deleted when used in a with statement

def __exit__(self, exc, value, tb):

result = self.file.__exit__(exc, value, tb)

self.close()

return result

def close(self):

"""

Close the temporary file, possibly deleting it.

"""

self._closer.close()

# iter() doesn't use __getattr__ to find the __iter__ method

def __iter__(self):

# Don't return iter(self.file), but yield from it to avoid closing

# file as long as it's being used as iterator (see issue #23700). We

# can't use 'yield from' here because iter(file) returns the file

# object itself, which has a close method, and thus the file would get

# closed when the generator is finalized, due to PEP380 semantics.

for line in self.file:

yield line

def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None,

newline=None, suffix=None, prefix=None,

dir=None, delete=True, *, errors=None):

"""Create and return a temporary file.

Arguments:

'prefix', 'suffix', 'dir' -- as for mkstemp.

'mode' -- the mode argument to io.open (default "w+b").

'buffering' -- the buffer size argument to io.open (default -1).

'encoding' -- the encoding argument to io.open (default None)

'newline' -- the newline argument to io.open (default None)

'delete' -- whether the file is deleted on close (default True).

'errors' -- the errors argument to io.open (default None)

The file is created as mkstemp() would do it.

Returns an object with a file-like interface; the name of the file

is accessible as its 'name' attribute. The file will be automatically

deleted when it is closed unless the 'delete' argument is set to False.

"""

prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)

flags = _bin_openflags

# Setting O_TEMPORARY in the flags causes the OS to delete

# the file when it is closed. This is only supported by Windows.

if _os.name == 'nt' and delete:

flags |= _os.O_TEMPORARY

(fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type)

try:

file = _io.open(fd, mode, buffering=buffering,

newline=newline, encoding=encoding, errors=errors)

return _TemporaryFileWrapper(file, name, delete)

except BaseException:

_os.unlink(name)

_os.close(fd)

raise

if _os.name != 'posix' or _sys.platform == 'cygwin':

# On non-POSIX and Cygwin systems, assume that we cannot unlink a file

# while it is open.

TemporaryFile = NamedTemporaryFile

else:

# Is the O_TMPFILE flag available and does it work?

# The flag is set to False if os.open(dir, os.O_TMPFILE) raises an

# IsADirectoryError exception

_O_TMPFILE_WORKS = hasattr(_os, 'O_TMPFILE')

def TemporaryFile(mode='w+b', buffering=-1, encoding=None,

newline=None, suffix=None, prefix=None,

dir=None, *, errors=None):

"""Create and return a temporary file.

Arguments:

'prefix', 'suffix', 'dir' -- as for mkstemp.

'mode' -- the mode argument to io.open (default "w+b").

'buffering' -- the buffer size argument to io.open (default -1).

'encoding' -- the encoding argument to io.open (default None)

'newline' -- the newline argument to io.open (default None)

'errors' -- the errors argument to io.open (default None)

The file is created as mkstemp() would do it.

Returns an object with a file-like interface. The file has no

name, and will cease to exist when it is closed.

"""

global _O_TMPFILE_WORKS

prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)

flags = _bin_openflags

if _O_TMPFILE_WORKS:

try:

flags2 = (flags | _os.O_TMPFILE) & ~_os.O_CREAT

fd = _os.open(dir, flags2, 0o600)

except IsADirectoryError:

# Linux kernel older than 3.11 ignores the O_TMPFILE flag:

# O_TMPFILE is read as O_DIRECTORY. Trying to open a directory

# with O_RDWR|O_DIRECTORY fails with IsADirectoryError, a

# directory cannot be open to write. Set flag to False to not

# try again.

_O_TMPFILE_WORKS = False

except OSError:

# The filesystem of the directory does not support O_TMPFILE.

# For example, OSError(95, 'Operation not supported').

#

# On Linux kernel older than 3.11, trying to open a regular

# file (or a symbolic link to a regular file) with O_TMPFILE

# fails with NotADirectoryError, because O_TMPFILE is read as

# O_DIRECTORY.

pass

else:

try:

return _io.open(fd, mode, buffering=buffering,

newline=newline, encoding=encoding,

errors=errors)

except:

_os.close(fd)

raise

# Fallback to _mkstemp_inner().

(fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type)

try:

_os.unlink(name)

return _io.open(fd, mode, buffering=buffering,

newline=newline, encoding=encoding, errors=errors)

except:

_os.close(fd)

raise

class SpooledTemporaryFile:

"""Temporary file wrapper, specialized to switch from BytesIO

or StringIO to a real file when it exceeds a certain size or

when a fileno is needed.

"""

_rolled = False

def __init__(self, max_size=0, mode='w+b', buffering=-1,

encoding=None, newline=None,

suffix=None, prefix=None, dir=None, *, errors=None):

if 'b' in mode:

self._file = _io.BytesIO()

else:

self._file = _io.TextIOWrapper(_io.BytesIO(),

encoding=encoding, errors=errors,

newline=newline)

self._max_size = max_size

self._rolled = False

self._TemporaryFileArgs = {'mode': mode, 'buffering': buffering,

'suffix': suffix, 'prefix': prefix,

'encoding': encoding, 'newline': newline,

'dir': dir, 'errors': errors}

def _check(self, file):

if self._rolled: return

max_size = self._max_size

if max_size and file.tell() > max_size:

self.rollover()

def rollover(self):

if self._rolled: return

file = self._file

newfile = self._file = TemporaryFile(**self._TemporaryFileArgs)

del self._TemporaryFileArgs

pos = file.tell()

if hasattr(newfile, 'buffer'):

newfile.buffer.write(file.detach().getvalue())

else:

newfile.write(file.getvalue())

newfile.seek(pos, 0)

self._rolled = True

# The method caching trick from NamedTemporaryFile

# won't work here, because _file may change from a

# BytesIO/StringIO instance to a real file. So we list

# all the methods directly.

# Context management protocol

def __enter__(self):

if self._file.closed:

raise ValueError("Cannot enter context with closed file")

return self

def __exit__(self, exc, value, tb):

self._file.close()

# file protocol

def __iter__(self):

return self._file.__iter__()

def close(self):

self._file.close()

@property

def closed(self):

return self._file.closed

@property

def encoding(self):

return self._file.encoding

@property

def errors(self):

return self._file.errors

def fileno(self):

self.rollover()

return self._file.fileno()

def flush(self):

self._file.flush()

def isatty(self):

return self._file.isatty()

@property

def mode(self):

try:

return self._file.mode

except AttributeError:

return self._TemporaryFileArgs['mode']

@property

def name(self):

try:

return self._file.name

except AttributeError:

return None

@property

def newlines(self):

return self._file.newlines

def read(self, *args):

return self._file.read(*args)

def readline(self, *args):

return self._file.readline(*args)

def readlines(self, *args):

return self._file.readlines(*args)

def seek(self, *args):

return self._file.seek(*args)

@property

def softspace(self):

return self._file.softspace

def tell(self):

return self._file.tell()

def truncate(self, size=None):

if size is None:

self._file.truncate()

else:

if size > self._max_size:

self.rollover()

self._file.truncate(size)

def write(self, s):

file = self._file

rv = file.write(s)

self._check(file)

return rv

def writelines(self, iterable):

file = self._file

rv = file.writelines(iterable)

self._check(file)

return rv

class TemporaryDirectory(object):

"""Create and return a temporary directory. This has the same

behavior as mkdtemp but can be used as a context manager. For

example:

with TemporaryDirectory() as tmpdir:

...

Upon exiting the context, the directory and everything contained

in it are removed.

"""

def __init__(self, suffix=None, prefix=None, dir=None):

self.name = mkdtemp(suffix, prefix, dir)

self._finalizer = _weakref.finalize(

self, self._cleanup, self.name,

warn_message="Implicitly cleaning up {!r}".format(self))

@classmethod

def _rmtree(cls, name):

def onerror(func, path, exc_info):

if issubclass(exc_info[0], PermissionError):

try:

if path != name:

_resetperms(_os.path.dirname(path))

_resetperms(path)

try:

_os.unlink(path)

# PermissionError is raised on FreeBSD for directories

except (IsADirectoryError, PermissionError):

cls._rmtree(path)

except FileNotFoundError:

pass

elif issubclass(exc_info[0], FileNotFoundError):

pass

else:

raise

_shutil.rmtree(name, onerror=onerror)

@classmethod

def _cleanup(cls, name, warn_message):

cls._rmtree(name)

_warnings.warn(warn_message, ResourceWarning)

def __repr__(self):

return "<{} {!r}>".format(self.__class__.__name__, self.name)

def __enter__(self):

return self.name

def __exit__(self, exc, value, tb):

self.cleanup()

def cleanup(self):

if self._finalizer.detach():

self._rmtree(self.name)