Python Dataset.get方法代码示例

# 需要导入模块: from pydicom.dataset import Dataset [as 别名]
# 或者: from pydicom.dataset.Dataset import get [as 别名]
    def testGetFromRaw(self):
        """Dataset: get(tag) returns same object as ds[tag] for raw element."""
        # This came from issue 88, where get(tag#) returned a RawDataElement,
        #     while get(name) converted to a true DataElement
        test_tag = 0x100010
        test_elem = RawDataElement(Tag(test_tag), "PN", 4, b"test", 0, True, True)
        ds = Dataset({Tag(test_tag): test_elem})
        by_get = ds.get(test_tag)
        by_item = ds[test_tag]

        msg = "Dataset.get() returned different objects for ds.get(tag) " "and ds[tag]:\nBy get():%r\nBy ds[tag]:%r\n"
        self.assertEqual(by_get, by_item, msg % (by_get, by_item))

# 需要导入模块: from pydicom.dataset import Dataset [as 别名]
# 或者: from pydicom.dataset.Dataset import get [as 别名]
def read_partial(fileobj, stop_when=None, defer_size=None, force=False):
    """Parse a DICOM file until a condition is met.

    Parameters
    ----------
    fileobj : a file-like object
        Note that the file will not close when the function returns.
    stop_when :
        Stop condition. See ``read_dataset`` for more info.
    defer_size : int, str, None, optional
        See ``read_file`` for parameter info.
    force : boolean
        See ``read_file`` for parameter info.

    Notes
    -----
    Use ``read_file`` unless you need to stop on some condition
    other than reaching pixel data.

    Returns
    -------
    FileDataset instance or DicomDir instance.

    See Also
    --------
    read_file
        More generic file reading function.
    """
    # Read preamble -- raise an exception if missing and force=False
    preamble = read_preamble(fileobj, force)
    file_meta_dataset = Dataset()
    # Assume a transfer syntax, correct it as necessary
    is_implicit_VR = True
    is_little_endian = True
    if preamble:
        file_meta_dataset = _read_file_meta_info(fileobj)
        transfer_syntax = file_meta_dataset.TransferSyntaxUID
        if transfer_syntax == pydicom.uid.ImplicitVRLittleEndian:
            pass
        elif transfer_syntax == pydicom.uid.ExplicitVRLittleEndian:
            is_implicit_VR = False
        elif transfer_syntax == pydicom.uid.ExplicitVRBigEndian:
            is_implicit_VR = False
            is_little_endian = False
        elif transfer_syntax == pydicom.uid.DeflatedExplicitVRLittleEndian:
            # See PS3.6-2008 A.5 (p 71)
            # when written, the entire dataset following
            #     the file metadata was prepared the normal way,
            #     then "deflate" compression applied.
            #  All that is needed here is to decompress and then
            #     use as normal in a file-like object
            zipped = fileobj.read()
            # -MAX_WBITS part is from comp.lang.python answer:
            # groups.google.com/group/comp.lang.python/msg/e95b3b38a71e6799
            unzipped = zlib.decompress(zipped, -zlib.MAX_WBITS)
            fileobj = BytesIO(unzipped)  # a file-like object
            is_implicit_VR = False
        else:
            # Any other syntax should be Explicit VR Little Endian,
            #   e.g. all Encapsulated (JPEG etc) are ExplVR-LE
            #        by Standard PS 3.5-2008 A.4 (p63)
            is_implicit_VR = False
    else:  # no header -- use the is_little_endian, implicit assumptions
        file_meta_dataset.TransferSyntaxUID = pydicom.uid.ImplicitVRLittleEndian

    try:
        dataset = read_dataset(fileobj, is_implicit_VR, is_little_endian,
                               stop_when=stop_when, defer_size=defer_size)
    except EOFError:
        pass  # error already logged in read_dataset

    class_uid = file_meta_dataset.get("MediaStorageSOPClassUID", None)
    if class_uid and class_uid == "Media Storage Directory Storage":
        return DicomDir(fileobj, dataset, preamble, file_meta_dataset,
                        is_implicit_VR, is_little_endian)
    else:
        return FileDataset(fileobj, dataset, preamble, file_meta_dataset,
                           is_implicit_VR, is_little_endian)

# 需要导入模块: from pydicom.dataset import Dataset [as 别名]
# 或者: from pydicom.dataset.Dataset import get [as 别名]
def read_partial(fileobj, stop_when=None, defer_size=None, force=False):
    """Parse a DICOM file until a condition is met.

    Parameters
    ----------
    fileobj : a file-like object
        Note that the file will not close when the function returns.
    stop_when :
        Stop condition. See ``read_dataset`` for more info.
    defer_size : int, str, None, optional
        See ``read_file`` for parameter info.
    force : boolean
        See ``read_file`` for parameter info.

    Notes
    -----
    Use ``read_file`` unless you need to stop on some condition
    other than reaching pixel data.

    Returns
    -------
    FileDataset instance or DicomDir instance.

    See Also
    --------
    read_file
        More generic file reading function.
    """
    # Read preamble -- raise an exception if missing and force=False
    preamble = read_preamble(fileobj, force)
    file_meta_dataset = Dataset()
    # Assume a transfer syntax, correct it as necessary
    is_implicit_VR = True
    is_little_endian = True
    if preamble:
        file_meta_dataset = _read_file_meta_info(fileobj)
        transfer_syntax = file_meta_dataset.get("TransferSyntaxUID")
        if transfer_syntax is None:  # issue 258
            # Assume and set ImplicitVRLittleEndian transfer syntax
            file_meta_dataset.TransferSyntaxUID = \
                pydicom.uid.ImplicitVRLittleEndian
        elif transfer_syntax == pydicom.uid.ImplicitVRLittleEndian:
            pass
        elif transfer_syntax == pydicom.uid.ExplicitVRLittleEndian:
            is_implicit_VR = False
        elif transfer_syntax == pydicom.uid.ExplicitVRBigEndian:
            is_implicit_VR = False
            is_little_endian = False
        elif transfer_syntax == pydicom.uid.DeflatedExplicitVRLittleEndian:
            # See PS3.6-2008 A.5 (p 71)
            # when written, the entire dataset following
            #     the file metadata was prepared the normal way,
            #     then "deflate" compression applied.
            #  All that is needed here is to decompress and then
            #     use as normal in a file-like object
            zipped = fileobj.read()
            # -MAX_WBITS part is from comp.lang.python answer:
            # groups.google.com/group/comp.lang.python/msg/e95b3b38a71e6799
            unzipped = zlib.decompress(zipped, -zlib.MAX_WBITS)
            fileobj = BytesIO(unzipped)  # a file-like object
            is_implicit_VR = False
        else:
            # Any other syntax should be Explicit VR Little Endian,
            #   e.g. all Encapsulated (JPEG etc) are ExplVR-LE
            #        by Standard PS 3.5-2008 A.4 (p63)
            is_implicit_VR = False
    else:  # no header -- use the is_little_endian, implicit assumptions
        file_meta_dataset.TransferSyntaxUID = pydicom.uid.ImplicitVRLittleEndian
        endian_chr = "<"
        element_struct = Struct(endian_chr + "HH2sH")
        # Try reading first 8 bytes
        group, elem, VR, length = element_struct.unpack(fileobj.read(8))
        # Rewind file object
        fileobj.seek(0)
        # If the VR is a valid VR, assume Explicit VR transfer systax
        from pydicom.values import converters
        if not in_py2:
            VR = VR.decode(default_encoding)
        if VR in converters.keys():
            is_implicit_VR = False
            # Determine if group in low numbered range (Little vs Big Endian)
            if group == 0:  # got (0,0) group length. Not helpful.
                # XX could use similar to http://www.dclunie.com/medical-image-faq/html/part2.html code example
                msg = ("Not able to guess transfer syntax when first item "
                       "is group length")
                raise NotImplementedError(msg)
            if group < 2000:
                file_meta_dataset.TransferSyntaxUID = pydicom.uid.ExplicitVRLittleEndian
            else:
                file_meta_dataset.TransferSyntaxUID = pydicom.uid.ExplicitVRBigEndian
                is_little_endian = False

    try:
        dataset = read_dataset(fileobj, is_implicit_VR, is_little_endian,
                               stop_when=stop_when, defer_size=defer_size)
    except EOFError:
        pass  # error already logged in read_dataset

    class_uid = file_meta_dataset.get("MediaStorageSOPClassUID", None)
    if class_uid and class_uid == "Media Storage Directory Storage":
#.........这里部分代码省略.........