示例#1
0
def open(fp,
         mode='r',
         driver=None,
         width=None,
         height=None,
         count=None,
         crs=None,
         transform=None,
         dtype=None,
         nodata=None,
         sharing=False,
         **kwargs):
    """Open a dataset for reading or writing.

    The dataset may be located in a local file, in a resource located by
    a URL, or contained within a stream of bytes.

    In read ('r') or read/write ('r+') mode, no keyword arguments are
    required: these attributes are supplied by the opened dataset.

    In write ('w' or 'w+') mode, the driver, width, height, count, and dtype
    keywords are strictly required.

    Parameters
    ----------
    fp : str, file object or pathlib.Path object
        A filename or URL, a file object opened in binary ('rb') mode,
        or a Path object.
    mode : str, optional
        'r' (read, the default), 'r+' (read/write), 'w' (write), or
        'w+' (write/read).
    driver : str, optional
        A short format driver name (e.g. "GTiff" or "JPEG") or a list of
        such names (see GDAL docs at
        http://www.gdal.org/formats_list.html). In 'w' or 'w+' modes
        a single name is required. In 'r' or 'r+' modes the driver can
        usually be omitted. Registered drivers will be tried
        sequentially until a match is found. When multiple drivers are
        available for a format such as JPEG2000, one of them can be
        selected by using this keyword argument.
    width : int, optional
        The number of columns of the raster dataset. Required in 'w' or
        'w+' modes, it is ignored in 'r' or 'r+' modes.
    height : int, optional
        The number of rows of the raster dataset. Required in 'w' or
        'w+' modes, it is ignored in 'r' or 'r+' modes.
    count : int, optional
        The count of dataset bands. Required in 'w' or 'w+' modes, it is
        ignored in 'r' or 'r+' modes.
    crs : str, dict, or CRS; optional
        The coordinate reference system. Required in 'w' or 'w+' modes,
        it is ignored in 'r' or 'r+' modes.
    transform : Affine instance, optional
        Affine transformation mapping the pixel space to geographic
        space. Required in 'w' or 'w+' modes, it is ignored in 'r' or
        'r+' modes.
    dtype : str or numpy dtype
        The data type for bands. For example: 'uint8' or
        ``rasterio.uint16``. Required in 'w' or 'w+' modes, it is
        ignored in 'r' or 'r+' modes.
    nodata : int, float, or nan; optional
        Defines the pixel value to be interpreted as not valid data.
        Required in 'w' or 'w+' modes, it is ignored in 'r' or 'r+'
        modes.
    sharing : bool; optional
        To reduce overhead and prevent programs from running out of file
        descriptors, rasterio maintains a pool of shared low level
        dataset handles. When `True` this function will use a shared
        handle if one is available. Multithreaded programs must avoid
        sharing and should set *sharing* to `False`.
    kwargs : optional
        These are passed to format drivers as directives for creating or
        interpreting datasets. For example: in 'w' or 'w+' modes
        a `tiled=True` keyword argument will direct the GeoTIFF format
        driver to create a tiled, rather than striped, TIFF.

    Returns
    -------
    A ``DatasetReader`` or ``DatasetWriter`` object.

    Examples
    --------

    To open a GeoTIFF for reading using standard driver discovery and
    no directives:

    >>> import rasterio
    >>> with rasterio.open('example.tif') as dataset:
    ...     print(dataset.profile)

    To open a JPEG2000 using only the JP2OpenJPEG driver:

    >>> with rasterio.open(
    ...         'example.jp2', driver='JP2OpenJPEG') as dataset:
    ...     print(dataset.profile)

    To create a new 8-band, 16-bit unsigned, tiled, and LZW-compressed
    GeoTIFF with a global extent and 0.5 degree resolution:

    >>> from rasterio.transform import from_origin
    >>> with rasterio.open(
    ...         'example.tif', 'w', driver='GTiff', dtype='uint16',
    ...         width=720, height=360, count=8, crs='EPSG:4326',
    ...         transform=from_origin(-180.0, 90.0, 0.5, 0.5),
    ...         nodata=0, tiled=True, compress='lzw') as dataset:
    ...     dataset.write(...)
    """

    if not isinstance(fp, string_types):
        if not (hasattr(fp, 'read') or hasattr(fp, 'write')
                or isinstance(fp, Path)):
            raise TypeError("invalid path or file: {0!r}".format(fp))
    if mode and not isinstance(mode, string_types):
        raise TypeError("invalid mode: {0!r}".format(mode))
    if driver and not isinstance(driver, string_types):
        raise TypeError("invalid driver: {0!r}".format(driver))
    if dtype and not check_dtype(dtype):
        raise TypeError("invalid dtype: {0!r}".format(dtype))
    if nodata is not None:
        nodata = float(nodata)
    if transform:
        transform = guard_transform(transform)

    # Check driver/mode blacklist.
    if driver and is_blacklisted(driver, mode):
        raise RasterioIOError("Blacklisted: file cannot be opened by "
                              "driver '{0}' in '{1}' mode".format(
                                  driver, mode))

    # Special case for file object argument.
    if mode == 'r' and hasattr(fp, 'read'):

        @contextmanager
        def fp_reader(fp):
            memfile = MemoryFile(fp.read())
            dataset = memfile.open(driver=driver, sharing=sharing)
            try:
                yield dataset
            finally:
                dataset.close()
                memfile.close()

        return fp_reader(fp)

    elif mode in ('w', 'w+') and hasattr(fp, 'write'):

        @contextmanager
        def fp_writer(fp):
            memfile = MemoryFile()
            dataset = memfile.open(driver=driver,
                                   width=width,
                                   height=height,
                                   count=count,
                                   crs=crs,
                                   transform=transform,
                                   dtype=dtype,
                                   nodata=nodata,
                                   sharing=sharing,
                                   **kwargs)
            try:
                yield dataset
            finally:
                dataset.close()
                memfile.seek(0)
                fp.write(memfile.read())
                memfile.close()

        return fp_writer(fp)

    else:
        # If a pathlib.Path instance is given, convert it to a string path.
        if isinstance(fp, Path):
            fp = str(fp)

        # The 'normal' filename or URL path.
        path = parse_path(fp)

        # Create dataset instances and pass the given env, which will
        # be taken over by the dataset's context manager if it is not
        # None.
        if mode == 'r':
            s = DatasetReader(path, driver=driver, sharing=sharing, **kwargs)
        elif mode == "r+":
            s = get_writer_for_path(path, driver=driver)(path,
                                                         mode,
                                                         driver=driver,
                                                         sharing=sharing,
                                                         **kwargs)
        elif mode.startswith("w"):
            if not driver:
                driver = driver_from_extension(path)
            writer = get_writer_for_driver(driver)
            if writer is not None:
                s = writer(path,
                           mode,
                           driver=driver,
                           width=width,
                           height=height,
                           count=count,
                           crs=crs,
                           transform=transform,
                           dtype=dtype,
                           nodata=nodata,
                           sharing=sharing,
                           **kwargs)
            else:
                raise DriverCapabilityError(
                    "Writer does not exist for driver: %s" % str(driver))
        else:
            raise DriverCapabilityError(
                "mode must be one of 'r', 'r+', or 'w', not %s" % mode)
        return s
示例#2
0
def open(fp, mode='r', driver=None, width=None, height=None, count=None,
         crs=None, transform=None, dtype=None, nodata=None, sharing=False,
         **kwargs):
    """Open a dataset for reading or writing.

    The dataset may be located in a local file, in a resource located by
    a URL, or contained within a stream of bytes.

    In read ('r') or read/write ('r+') mode, no keyword arguments are
    required: these attributes are supplied by the opened dataset.

    In write ('w' or 'w+') mode, the driver, width, height, count, and dtype
    keywords are strictly required.

    Parameters
    ----------
    fp : str, file object, PathLike object, FilePath, or MemoryFile
        A filename or URL, a file object opened in binary ('rb') mode, a
        Path object, or one of the rasterio classes that provides the
        dataset-opening interface (has an open method that returns a
        dataset).
    mode : str, optional
        'r' (read, the default), 'r+' (read/write), 'w' (write), or
        'w+' (write/read).
    driver : str, optional
        A short format driver name (e.g. "GTiff" or "JPEG") or a list of
        such names (see GDAL docs at
        https://gdal.org/drivers/raster/index.html). In 'w' or 'w+' modes
        a single name is required. In 'r' or 'r+' modes the driver can
        usually be omitted. Registered drivers will be tried
        sequentially until a match is found. When multiple drivers are
        available for a format such as JPEG2000, one of them can be
        selected by using this keyword argument.
    width : int, optional
        The number of columns of the raster dataset. Required in 'w' or
        'w+' modes, it is ignored in 'r' or 'r+' modes.
    height : int, optional
        The number of rows of the raster dataset. Required in 'w' or
        'w+' modes, it is ignored in 'r' or 'r+' modes.
    count : int, optional
        The count of dataset bands. Required in 'w' or 'w+' modes, it is
        ignored in 'r' or 'r+' modes.
    crs : str, dict, or CRS; optional
        The coordinate reference system. Required in 'w' or 'w+' modes,
        it is ignored in 'r' or 'r+' modes.
    transform : Affine instance, optional
        Affine transformation mapping the pixel space to geographic
        space. Required in 'w' or 'w+' modes, it is ignored in 'r' or
        'r+' modes.
    dtype : str or numpy dtype
        The data type for bands. For example: 'uint8' or
        ``rasterio.uint16``. Required in 'w' or 'w+' modes, it is
        ignored in 'r' or 'r+' modes.
    nodata : int, float, or nan; optional
        Defines the pixel value to be interpreted as not valid data.
        Required in 'w' or 'w+' modes, it is ignored in 'r' or 'r+'
        modes.
    sharing : bool; optional
        To reduce overhead and prevent programs from running out of file
        descriptors, rasterio maintains a pool of shared low level
        dataset handles. When `True` this function will use a shared
        handle if one is available. Multithreaded programs must avoid
        sharing and should set *sharing* to `False`.
    kwargs : optional
        These are passed to format drivers as directives for creating or
        interpreting datasets. For example: in 'w' or 'w+' modes
        a `tiled=True` keyword argument will direct the GeoTIFF format
        driver to create a tiled, rather than striped, TIFF.

    Returns
    -------
    A ``DatasetReader`` or ``DatasetWriter`` object.

    Examples
    --------

    To open a GeoTIFF for reading using standard driver discovery and
    no directives:

    >>> import rasterio
    >>> with rasterio.open('example.tif') as dataset:
    ...     print(dataset.profile)

    To open a JPEG2000 using only the JP2OpenJPEG driver:

    >>> with rasterio.open(
    ...         'example.jp2', driver='JP2OpenJPEG') as dataset:
    ...     print(dataset.profile)

    To create a new 8-band, 16-bit unsigned, tiled, and LZW-compressed
    GeoTIFF with a global extent and 0.5 degree resolution:

    >>> from rasterio.transform import from_origin
    >>> with rasterio.open(
    ...         'example.tif', 'w', driver='GTiff', dtype='uint16',
    ...         width=720, height=360, count=8, crs='EPSG:4326',
    ...         transform=from_origin(-180.0, 90.0, 0.5, 0.5),
    ...         nodata=0, tiled=True, compress='lzw') as dataset:
    ...     dataset.write(...)
    """

    if not isinstance(fp, str):
        if not (
            hasattr(fp, "read")
            or hasattr(fp, "write")
            or isinstance(fp, (os.PathLike, MemoryFile, FilePath))
        ):
            raise TypeError("invalid path or file: {0!r}".format(fp))
    if mode and not isinstance(mode, str):
        raise TypeError("invalid mode: {0!r}".format(mode))
    if driver and not isinstance(driver, str):
        raise TypeError("invalid driver: {0!r}".format(driver))
    if dtype and not check_dtype(dtype):
        raise TypeError("invalid dtype: {0!r}".format(dtype))
    if nodata is not None:
        nodata = float(nodata)
    if transform:
        transform = guard_transform(transform)

    # Check driver/mode blacklist.
    if driver and is_blacklisted(driver, mode):
        raise RasterioIOError(
            "Blacklisted: file cannot be opened by "
            "driver '{0}' in '{1}' mode".format(driver, mode))

    # If the fp argument is a file-like object and can be adapted by
    # rasterio's FilePath we do so. Otherwise, we use a MemoryFile to
    # hold fp's contents and store that in an ExitStack attached to the
    # dataset object that we will return. When a dataset's close method
    # is called, this ExitStack will be unwound and the MemoryFile's
    # storage will be cleaned up.
    if mode == 'r' and hasattr(fp, 'read'):
        if have_vsi_plugin:
            return FilePath(fp).open(driver=driver, sharing=sharing, **kwargs)
        else:
            memfile = MemoryFile(fp.read())
            dataset = memfile.open(driver=driver, sharing=sharing, **kwargs)
            dataset._env.enter_context(memfile)
            return dataset

    elif mode in ('w', 'w+') and hasattr(fp, 'write'):
        memfile = MemoryFile()
        dataset = memfile.open(
            driver=driver,
            width=width,
            height=height,
            count=count,
            crs=crs,
            transform=transform,
            dtype=dtype,
            nodata=nodata,
            sharing=sharing,
            **kwargs
        )
        dataset._env.enter_context(memfile)

        # For the writing case we push an extra callback onto the
        # ExitStack. It ensures that the MemoryFile's contents are
        # copied to the open file object.
        def func(*args, **kwds):
            memfile.seek(0)
            fp.write(memfile.read())

        dataset._env.callback(func)
        return dataset

    # TODO: test for a shared base class or abstract type.
    elif isinstance(fp, (FilePath, MemoryFile)):
        if mode.startswith("r"):
            dataset = fp.open(driver=driver, sharing=sharing, **kwargs)

        # Note: FilePath does not support writing and an exception will
        # result from this.
        elif mode.startswith("w"):
            dataset = fp.open(
                driver=driver,
                width=width,
                height=height,
                count=count,
                crs=crs,
                transform=transform,
                dtype=dtype,
                nodata=nodata,
                sharing=sharing,
                **kwargs
            )
        return dataset

    # At this point, the fp argument is a string or path-like object
    # which can be converted to a string.
    else:
        raw_dataset_path = os.fspath(fp)
        path = _parse_path(raw_dataset_path)

        if mode == "r":
            dataset = DatasetReader(path, driver=driver, sharing=sharing, **kwargs)
        elif mode == "r+":
            dataset = get_writer_for_path(path, driver=driver)(
                path, mode, driver=driver, sharing=sharing, **kwargs
            )
        elif mode.startswith("w"):
            if not driver:
                driver = driver_from_extension(path)
            writer = get_writer_for_driver(driver)
            if writer is not None:
                dataset = writer(
                    path,
                    mode,
                    driver=driver,
                    width=width,
                    height=height,
                    count=count,
                    crs=crs,
                    transform=transform,
                    dtype=dtype,
                    nodata=nodata,
                    sharing=sharing,
                    **kwargs
                )
            else:
                raise DriverCapabilityError(
                    "Writer does not exist for driver: %s" % str(driver)
                )
        else:
            raise DriverCapabilityError(
                "mode must be one of 'r', 'r+', or 'w', not %s" % mode)

        return dataset