Python os.stat() Examples

The following are 30 code examples of os.stat(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module os , or try the search function .
Example #1
Source File: test_tools.py    From delocate with BSD 2-Clause "Simplified" License 7 votes vote down vote up
def test_ensure_writable():
    # Test ensure writable decorator
    with InTemporaryDirectory():
        with open('test.bin', 'wt') as fobj:
            fobj.write('A line\n')
        # Set to user rw, else r
        os.chmod('test.bin', 0o644)
        st = os.stat('test.bin')
        @ensure_writable
        def foo(fname):
            pass
        foo('test.bin')
        assert_equal(os.stat('test.bin'), st)
        # No-one can write
        os.chmod('test.bin', 0o444)
        st = os.stat('test.bin')
        foo('test.bin')
        assert_equal(os.stat('test.bin'), st) 
Example #2
Source File: can_haz_image.py    From macops with Apache License 2.0 7 votes vote down vote up
def GetFileChecksum(self, filepath):
    """Generates checksum of given file.

    Args:
      filepath: String of filepath.

    Returns:
      f_hash: SHA1 hash for the file provided in filepath.
    """
    statinfo = os.stat(filepath)
    if statinfo.st_size/1048576 < 200:
      f_content = open(filepath, 'r').read()
      f_hash = hashlib.sha1(f_content).hexdigest()
      return f_hash
    else:
      cmd = ['shasum', filepath]
      (stdout, unused_sterr, unused_rc) = RunProcess(cmd)
      return stdout.split()[0] 
Example #3
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 6 votes vote down vote up
def stat(self, follow_symlinks=True):
            if follow_symlinks:
                if self._stat is None:
                    if self.is_symlink():
                        # It's a symlink, call link-following stat()
                        self._stat = stat(self.path)
                    else:
                        # Not a symlink, stat is same as lstat value
                        if self._lstat is None:
                            self._lstat = find_data_to_stat(self._find_data)
                        self._stat = self._lstat
                return self._stat
            else:
                if self._lstat is None:
                    # Lazily convert to stat object, because it's slow
                    # in Python, and often we only need is_dir() etc
                    self._lstat = find_data_to_stat(self._find_data)
                return self._lstat 
Example #4
Source File: runSysTrace.py    From InsightAgent with Apache License 2.0 6 votes vote down vote up
def updateFile(filepath, filename, newSession):
    global homepath
    file = os.path.join(homepath,filepath,filename)
    oldSession = "null"
    currentSession = "null"
    if (os.stat(file).st_size == 0):
        open(os.path.join(file), 'a+').writelines(newSession+"\n")
    else:
        lines = open(file).readlines()
        if len(lines) == 1:        
            currentSession = lines[0].rstrip('\n')
            lines.append(newSession+'\n')
            open(os.path.join(file), 'w+').writelines(lines[0:])
        else:
            lines.append(newSession+'\n')
            oldSession = lines[0].rstrip('\n')
            currentSession = lines[1].rstrip('\n')
            open(os.path.join(file), 'w+').writelines(lines[1:])
    return oldSession, currentSession 
Example #5
Source File: authority.py    From certidude with MIT License 6 votes vote down vote up
def get_revoked(serial):
    if isinstance(serial, str):
        serial = int(serial, 16)
    path = os.path.join(config.REVOKED_DIR, "%040x.pem" % serial)
    with open(path, "rb") as fh:
        buf = fh.read()
        header, _, der_bytes = pem.unarmor(buf)
        cert = x509.Certificate.load(der_bytes)
        try:
            reason = getxattr(path, "user.revocation.reason").decode("ascii")
        except IOError: # TODO: make sure it's not required
            reason = "key_compromise"
        return path, buf, cert, \
            cert["tbs_certificate"]["validity"]["not_before"].native.replace(tzinfo=None), \
            cert["tbs_certificate"]["validity"]["not_after"].native.replace(tzinfo=None), \
            datetime.utcfromtimestamp(os.stat(path).st_ctime), \
            reason 
Example #6
Source File: collectdReportMetrics.py    From InsightAgent with Apache License 2.0 6 votes vote down vote up
def remove_old_files(directory, filetype):
    now = datetime.datetime.now()
    now_time = now.time()
    # time between which each day the deletion is done
    if datetime.time(06, 30) <= now_time <= datetime.time(20, 35):
        # data directory path
        data_file_path = directory
        # data_file_path = os.path.join(homepath,datadir)
        now = time.time()
        for f in os.listdir(data_file_path):
            data_file = os.path.join(data_file_path, f)
            # check files older than 3 days
            if os.stat(data_file).st_mtime < now - 2 * 86400:
                # only delete csv files
                if filetype is None:
                    if os.path.isfile(data_file):
                        os.remove(data_file)
                else:
                    if str(filetype) in str(os.path.splitext(data_file)[1]):
                        # print data_file
                        if os.path.isfile(data_file):
                            os.remove(data_file) 
Example #7
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copystat_local_to_local_symlink_dont_follow_fail(tmpdir):
    test_dir = tmpdir.mkdir('test')
    src_filename = "%s\\source.txt" % test_dir
    dst_filename = "%s\\target.txt" % test_dir

    with open(src_filename, mode='w') as fd:
        fd.write(u"content")
    os.chmod(src_filename, stat.S_IREAD)

    with open(dst_filename, mode='w') as fd:
        fd.write(u"content")

    src_link = "%s\\source-link.txt" % test_dir
    dst_link = "%s\\target-link.txt" % test_dir

    os.symlink(src_filename, src_link)
    os.symlink(dst_filename, dst_link)

    expected = "follow_symlinks unavailable on this platform"
    with pytest.raises(NotImplementedError, match=re.escape(expected)):
        copystat(src_link, dst_link, follow_symlinks=False) 
Example #8
Source File: test_core.py    From cherrypy with BSD 3-Clause "New" or "Revised" License 6 votes vote down vote up
def setup_server():
        def break_header():
            # Add a header after finalize that is invalid
            cherrypy.serving.response.header_list.append((2, 3))
        cherrypy.tools.break_header = cherrypy.Tool(
            'on_end_resource', break_header)

        class Root:

            @cherrypy.expose
            def index(self):
                return 'hello'

            @cherrypy.config(**{'tools.break_header.on': True})
            def start_response_error(self):
                return 'salud!'

            @cherrypy.expose
            def stat(self, path):
                with cherrypy.HTTPError.handle(OSError, 404):
                    os.stat(path)

        root = Root()

        cherrypy.tree.mount(root) 
Example #9
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copystat_local_to_local(tmpdir):
    test_dir = tmpdir.mkdir("test")
    src_filename = "%s\\source.txt" % test_dir
    dst_filename = "%s\\target.txt" % test_dir

    with open(src_filename, mode='w') as fd:
        fd.write(u"content")
    os.chmod(src_filename, stat.S_IREAD)
    os.utime(src_filename, (1024, 1024))

    with open(dst_filename, mode='w') as fd:
        fd.write(u"content")

    copystat(src_filename, dst_filename)

    actual = os.stat(dst_filename)
    assert actual.st_atime == 1024
    assert actual.st_mtime == 1024
    assert stat.S_IMODE(actual.st_mode) & stat.S_IWRITE == 0 
Example #10
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copystat_remote_to_local(smb_share, tmpdir):
    test_dir = tmpdir.mkdir("test")
    src_filename = "%s\\source.txt" % smb_share
    dst_filename = "%s\\target.txt" % test_dir

    with open_file(src_filename, mode='w', file_attributes=FileAttributes.FILE_ATTRIBUTE_READONLY) as fd:
        fd.write(u"content")
    utime(src_filename, times=(1024, 1024))

    with open(dst_filename, mode='w') as fd:
        fd.write(u"content")

    copystat(src_filename, dst_filename)

    actual = os.stat(dst_filename)
    assert actual.st_atime == 1024
    assert actual.st_mtime == 1024
    assert stat.S_IMODE(actual.st_mode) & stat.S_IWRITE == 0 
Example #11
Source File: _util.py    From multibootusb with GNU General Public License v2.0 6 votes vote down vote up
def get_device_type(filename):
    """
    Get the device type of a device file.

    ``filename`` is a string containing the path of a device file.

    Return ``'char'`` if ``filename`` is a character device, or ``'block'`` if
    ``filename`` is a block device.  Raise :exc:`~exceptions.ValueError` if
    ``filename`` is no device file at all.  Raise
    :exc:`~exceptions.EnvironmentError` if ``filename`` does not exist or if
    its metadata was inaccessible.

    .. versionadded:: 0.15
    """
    mode = os.stat(filename).st_mode
    if stat.S_ISCHR(mode):
        return 'char'
    elif stat.S_ISBLK(mode):
        return 'block'
    else:
        raise ValueError('not a device file: {0!r}'.format(filename)) 
Example #12
Source File: httpResponse.py    From MicroWebSrv2 with MIT License 6 votes vote down vote up
def ReturnFile(self, filename, attachmentName=None) :
        if not isinstance(filename, str) or len(filename) == 0 :
            raise ValueError('"filename" must be a not empty string.')
        if attachmentName is not None and not isinstance(attachmentName, str) :
            raise ValueError('"attachmentName" must be a string or None.')
        try :
            size = stat(filename)[6]
        except :
            self.ReturnNotFound()
            return
        try :
            file = open(filename, 'rb')
        except :
            self.ReturnForbidden()
            return
        if attachmentName :
            cd = 'attachment; filename="%s"' % attachmentName.replace('"', "'")
            self.SetHeader('Content-Disposition', cd)
        if not self._contentType :
            self._contentType = self._mws2.GetMimeTypeFromFilename(filename)
        self._contentLength = size
        self.ReturnStream(200, file)

    # ------------------------------------------------------------------------ 
Example #13
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copystat_local_to_remote(smb_share, tmpdir):
    test_dir = tmpdir.mkdir("test")
    src_filename = "%s\\source.txt" % test_dir
    dst_filename = "%s\\target.txt" % smb_share

    with open(src_filename, mode='w') as fd:
        fd.write(u"content")
    os.chmod(src_filename, stat.S_IREAD)
    os.utime(src_filename, (1024, 1024))

    with open_file(dst_filename, mode='w') as fd:
        fd.write(u"content")

    copystat(src_filename, dst_filename)

    actual = smbclient_stat(dst_filename)
    assert actual.st_atime == 1024
    assert actual.st_mtime == 1024
    assert actual.st_file_attributes & FileAttributes.FILE_ATTRIBUTE_READONLY == FileAttributes.FILE_ATTRIBUTE_READONLY 
Example #14
Source File: download_and_convert_cifar10.py    From DOTA_models with Apache License 2.0 6 votes vote down vote up
def _download_and_uncompress_dataset(dataset_dir):
  """Downloads cifar10 and uncompresses it locally.

  Args:
    dataset_dir: The directory where the temporary files are stored.
  """
  filename = _DATA_URL.split('/')[-1]
  filepath = os.path.join(dataset_dir, filename)

  if not os.path.exists(filepath):
    def _progress(count, block_size, total_size):
      sys.stdout.write('\r>> Downloading %s %.1f%%' % (
          filename, float(count * block_size) / float(total_size) * 100.0))
      sys.stdout.flush()
    filepath, _ = urllib.request.urlretrieve(_DATA_URL, filepath, _progress)
    print()
    statinfo = os.stat(filepath)
    print('Successfully downloaded', filename, statinfo.st_size, 'bytes.')
    tarfile.open(filepath, 'r:gz').extractall(dataset_dir) 
Example #15
Source File: dataset_utils.py    From DOTA_models with Apache License 2.0 6 votes vote down vote up
def download_and_uncompress_tarball(tarball_url, dataset_dir):
  """Downloads the `tarball_url` and uncompresses it locally.

  Args:
    tarball_url: The URL of a tarball file.
    dataset_dir: The directory where the temporary files are stored.
  """
  filename = tarball_url.split('/')[-1]
  filepath = os.path.join(dataset_dir, filename)

  def _progress(count, block_size, total_size):
    sys.stdout.write('\r>> Downloading %s %.1f%%' % (
        filename, float(count * block_size) / float(total_size) * 100.0))
    sys.stdout.flush()
  filepath, _ = urllib.request.urlretrieve(tarball_url, filepath, _progress)
  print()
  statinfo = os.stat(filepath)
  print('Successfully downloaded', filename, statinfo.st_size, 'bytes.')
  tarfile.open(filepath, 'r:gz').extractall(dataset_dir) 
Example #16
Source File: generator_utils.py    From fine-lm with MIT License 6 votes vote down vote up
def gunzip_file(gz_path, new_path):
  """Unzips from gz_path into new_path.

  Args:
    gz_path: path to the zipped file.
    new_path: path to where the file will be unzipped.
  """
  if tf.gfile.Exists(new_path):
    tf.logging.info("File %s already exists, skipping unpacking" % new_path)
    return
  tf.logging.info("Unpacking %s to %s" % (gz_path, new_path))
  # We may be unpacking into a newly created directory, add write mode.
  mode = stat.S_IRWXU or stat.S_IXGRP or stat.S_IRGRP or stat.S_IROTH
  os.chmod(os.path.dirname(new_path), mode)
  with gzip.open(gz_path, "rb") as gz_file:
    with tf.gfile.GFile(new_path, mode="wb") as new_file:
      for line in gz_file:
        new_file.write(line) 
Example #17
Source File: cifar10.py    From DOTA_models with Apache License 2.0 6 votes vote down vote up
def maybe_download_and_extract():
  """Download and extract the tarball from Alex's website."""
  dest_directory = FLAGS.data_dir
  if not os.path.exists(dest_directory):
    os.makedirs(dest_directory)
  filename = DATA_URL.split('/')[-1]
  filepath = os.path.join(dest_directory, filename)
  if not os.path.exists(filepath):
    def _progress(count, block_size, total_size):
      sys.stdout.write('\r>> Downloading %s %.1f%%' % (filename,
          float(count * block_size) / float(total_size) * 100.0))
      sys.stdout.flush()
    filepath, _ = urllib.request.urlretrieve(DATA_URL, filepath, _progress)
    print()
    statinfo = os.stat(filepath)
    print('Successfully downloaded', filename, statinfo.st_size, 'bytes.')
  extracted_dir_path = os.path.join(dest_directory, 'cifar-10-batches-bin')
  if not os.path.exists(extracted_dir_path):
    tarfile.open(filepath, 'r:gz').extractall(dest_directory) 
Example #18
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copymode_remote_to_local(smb_share, tmpdir):
    test_dir = tmpdir.mkdir("test")
    src_filename = "%s\\source.txt" % smb_share
    dst_filename = "%s\\target.txt" % test_dir

    with open_file(src_filename, mode='w', file_attributes=FileAttributes.FILE_ATTRIBUTE_READONLY) as fd:
        fd.write(u"content")

    with open(dst_filename, mode='w') as fd:
        fd.write(u"content")

    copymode(src_filename, dst_filename)

    actual = os.stat(dst_filename).st_mode
    assert stat.S_IMODE(actual) & stat.S_IWRITE == 0

    remove(src_filename)
    with open_file(src_filename, mode='w') as fd:
        fd.write(u"content")

    copymode(src_filename, dst_filename)

    actual = os.stat(dst_filename).st_mode
    assert stat.S_IMODE(actual) & stat.S_IWRITE == stat.S_IWRITE 
Example #19
Source File: shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def copymode(src, dst, follow_symlinks=True, **kwargs):
    """
    Copy the permission bits from src to dst. The file contents, owner, and group are unaffected. Due to the
    limitations of Windows, this function only sets/unsets the dst's FILE_ATTRIBUTE_READ_ONLY flag based on what src's
    attribute is set to.

    If follow_symlinks is 'False', and both src and dst are symbolic links, copymode() will attempt to modify the mode
    of dst itself (rather than the file it points to).

    This function supports src and dst being either a local or UNC path. A relative path will be resolved based on the
    current working directory.

    :param src: The src file or directory to copy the read only flag from.
    :param dst: The dst file or directory to copy the read only flag to.
    :param follow_symlinks: Whether to copy the read only flag on the symlink or the target of the symlink.
    :param kwargs: Common arguments used to build the SMB Session for any UNC paths.
    """
    src_mode = stat.S_IMODE(_get_file_stat(src, follow_symlinks, **kwargs).st_mode)

    norm_dst = ntpath.normpath(dst)
    if norm_dst.startswith('\\\\'):
        read_only = not (src_mode & stat.S_IWRITE == stat.S_IWRITE and src_mode & stat.S_IREAD == stat.S_IREAD)
        _set_file_basic_info(dst, follow_symlinks, read_only=read_only, **kwargs)
    else:
        _local_chmod(dst, src_mode, follow_symlinks) 
Example #20
Source File: usb.py    From multibootusb with GNU General Public License v2.0 6 votes vote down vote up
def is_block(usb_disk):
    """
    Function to detect if the USB is block device
    :param usb_disk: USB disk path
    :return: True is devie is block device else False
    """
    import stat
    if platform.system() == 'Linux':
        if len(usb_disk) != 9:
            return False
    elif platform.system() == 'Windows':
        if len(usb_disk) != 2:
            return False
        else:
            return True
    try:
        mode = os.stat(usb_disk).st_mode
        gen.log(mode)
        gen.log(stat.S_ISBLK(mode))
    except:
        return False

    return stat.S_ISBLK(mode) 
Example #21
Source File: tools.py    From delocate with BSD 2-Clause "Simplified" License 6 votes vote down vote up
def ensure_permissions(mode_flags=stat.S_IWUSR):
    """decorator to ensure a filename has given permissions.

    If changed, original permissions are restored after the decorated
    modification.
    """

    def decorator(f):
        def modify(filename, *args, **kwargs):
            m = chmod_perms(filename) if exists(filename) else mode_flags
            if not m & mode_flags:
                os.chmod(filename, m | mode_flags)
            try:
                return f(filename, *args, **kwargs)
            finally:
                # restore original permissions
                if not m & mode_flags:
                    os.chmod(filename, m)
        return modify

    return decorator


# Open filename, checking for read permission 
Example #22
Source File: test_smbclient_shutil.py    From smbprotocol with MIT License 6 votes vote down vote up
def test_copymode_local_to_local_symlink_dont_follow(tmpdir):
    test_dir = tmpdir.mkdir('test')
    src_filename = "%s\\source.txt" % test_dir
    dst_filename = "%s\\target.txt" % test_dir

    with open(src_filename, mode='w') as fd:
        fd.write(u"content")
    os.chmod(src_filename, stat.S_IREAD)

    with open(dst_filename, mode='w') as fd:
        fd.write(u"content")

    src_link = "%s\\source-link.txt" % test_dir
    dst_link = "%s\\target-link.txt" % test_dir

    os.symlink(src_filename, src_link)
    os.symlink(dst_filename, dst_link)

    expected = "chmod: follow_symlinks unavailable on this platform"
    with pytest.raises(NotImplementedError, match=re.escape(expected)):
        copymode(src_link, dst_link, follow_symlinks=False) 
Example #23
Source File: ingest_cub200.py    From ArtGAN with BSD 3-Clause "New" or "Revised" License 5 votes vote down vote up
def transform_and_save(img_path, target_size, output_filename, skip=False):
    """
    Takes an image and
    optionally transforms it and then writes it out to output_filename
    """
    if skip and os.path.exists(output_filename):
        return
    img = Image.open(img_path)
    width, height = img.size

    # Take the smaller image dimension down to target_size
    # while retaining aspect_ration. Otherwise leave it alone
    if width < height:
        if width > target_size:
            scale_factor = float(target_size) / width
            width = target_size
            height = int(height*scale_factor)
    else:
        if height > target_size:
            scale_factor = float(target_size) / height
            height = target_size
            width = int(width*scale_factor)
    if img.size[0] != width or img.size[1] != height:
        img = img.resize((width, height), resample=Image.LANCZOS)
        img.save(output_filename, quality=100)
    else:
        # Avoid recompression by saving file out directly without transformation
        shutil.copy(img_path, output_filename)
    assert (os.stat(output_filename).st_size > 0), "{} has size 0".format(output_filename) 
Example #24
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 5 votes vote down vote up
def is_file(self, follow_symlinks=True):
        try:
            st = self.stat(follow_symlinks=follow_symlinks)
        except OSError as e:
            if e.errno != ENOENT:
                raise
            return False  # Path doesn't exist or is a broken symlink
        return st.st_mode & 0o170000 == S_IFREG 
Example #25
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 5 votes vote down vote up
def is_symlink(self):
        try:
            st = self.stat(follow_symlinks=False)
        except OSError as e:
            if e.errno != ENOENT:
                raise
            return False  # Path doesn't exist or is a broken symlink
        return st.st_mode & 0o170000 == S_IFLNK 
Example #26
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 5 votes vote down vote up
def stat(self, follow_symlinks=True):
        if follow_symlinks:
            if self._stat is None:
                self._stat = stat(self.path)
            return self._stat
        else:
            if self._lstat is None:
                self._lstat = lstat(self.path)
            return self._lstat 
Example #27
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 5 votes vote down vote up
def is_file(self, follow_symlinks=True):
                if follow_symlinks and self.is_symlink():
                    try:
                        st = self.stat()
                    except OSError as e:
                        if e.errno != ENOENT:
                            raise
                        return False
                else:
                    st = self._lstat
                return st.st_mode & 0o170000 == S_IFREG 
Example #28
Source File: scandir.py    From ANGRYsearch with GNU General Public License v2.0 5 votes vote down vote up
def is_dir(self, follow_symlinks=True):
        try:
            st = self.stat(follow_symlinks=follow_symlinks)
        except OSError as e:
            if e.errno != ENOENT:
                raise
            return False  # Path doesn't exist or is a broken symlink
        return st.st_mode & 0o170000 == S_IFDIR 
Example #29
Source File: generator_utils.py    From fine-lm with MIT License 5 votes vote down vote up
def maybe_download(directory, filename, uri):
  """Download filename from uri unless it's already in directory.

  Copies a remote file to local if that local file does not already exist.  If
  the local file pre-exists this function call, it does not check that the local
  file is a copy of the remote.

  Remote filenames can be filepaths, any URI readable by tensorflow.gfile, or a
  URL.

  Args:
    directory: path to the directory that will be used.
    filename: name of the file to download to (do nothing if it already exists).
    uri: URI to copy (or download) from.

  Returns:
    The path to the downloaded file.
  """
  tf.gfile.MakeDirs(directory)
  filepath = os.path.join(directory, filename)
  if tf.gfile.Exists(filepath):
    tf.logging.info("Not downloading, file already found: %s" % filepath)
    return filepath

  tf.logging.info("Downloading %s to %s" % (uri, filepath))
  try:
    tf.gfile.Copy(uri, filepath)
  except tf.errors.UnimplementedError:
    if uri.startswith("http"):
      inprogress_filepath = filepath + ".incomplete"
      inprogress_filepath, _ = urllib.urlretrieve(
          uri, inprogress_filepath, reporthook=download_report_hook)
      # Print newline to clear the carriage return from the download progress
      print()
      tf.gfile.Rename(inprogress_filepath, filepath)
    else:
      raise ValueError("Unrecognized URI: " + filepath)
  statinfo = os.stat(filepath)
  tf.logging.info("Successfully downloaded %s, %s bytes." %
                  (filename, statinfo.st_size))
  return filepath 
Example #30
Source File: ingest_flower102.py    From ArtGAN with BSD 3-Clause "New" or "Revised" License 5 votes vote down vote up
def transform_and_save(img_path, target_size, output_filename, skip=False):
    """
    Takes an image and
    optionally transforms it and then writes it out to output_filename
    """
    if skip and os.path.exists(output_filename):
        return
    img = Image.open(img_path)
    width, height = img.size

    # Take the smaller image dimension down to target_size
    # while retaining aspect_ration. Otherwise leave it alone
    if width < height:
        if width > target_size:
            scale_factor = float(target_size) / width
            width = target_size
            height = int(height*scale_factor)
    else:
        if height > target_size:
            scale_factor = float(target_size) / height
            height = target_size
            width = int(width*scale_factor)
    if img.size[0] != width or img.size[1] != height:
        img = img.resize((width, height), resample=Image.LANCZOS)
        img.save(output_filename, quality=100)
    else:
        # Avoid recompression by saving file out directly without transformation
        shutil.copy(img_path, output_filename)
    assert (os.stat(output_filename).st_size > 0), "{} has size 0".format(output_filename)