+General library to get driver names and extensions for all supported
+Author: Dan Clewley (dac)
+License restrictions: None known. Uses GDAL (MIT/X license)
+Known issues: Some drivers must be used with creation options to get the desired
+output. For example .bil and .bsq both use the ENVI driver but must use creation
+options to specify the interleave.
+* GDALDrivers().get_driver_from_ext - Get GDAL driver from extension
+* GDALDrivers().get_ext_from_driver - Get extension from GDAL driver name
+* GDALDrivers().get_creation_options_from_ext - Get GDAL creation options from extension
+* GDALDrivers().get_creation_options_from_driver - Get GDAL creation options driver name
+#: List of Non-GDAL extensions (mostly for ENVI)
+NON_GDAL_DRIVER_FROM_EXT = {'bil' : 'ENVI',
+#: Preferred creation options for GDAL
+GDAL_CREATION_OPTIONS = {'bil' : ['INTERLEAVE=BIL'],
+ 'bsq' : ['INTERLEAVE=BSQ'],
+ 'tif' : ['COMPRESS=LZW']}
+class GDALDrivers(object):
+ Class to get GDAL drivers or
+ Gets list of all available GDAL drivers and adds some
+ additional extensions for existing drives (e.g., for ENVI)
+ import get_gdal_drivers
+ get_gdal_drivers.GDALDrivers().get_driver_from_ext('.tif')
+ get_gdal_drivers.GDALDrivers().get_ext_from_driver('GTiff')
+ # Set up two empty dictionaries
+ # One uses the extension as the key and one the driver
+ self.gdal_ext_from_driver = {}
+ self.gdal_driver_from_ext = {}
+ # Go through all drivers registered to GDAL
+ for driver_num in range(gdal.GetDriverCount()):
+ driver = gdal.GetDriver(driver_num)
+ driver_ext = driver.GetMetadata()['DMD_EXTENSION']
+ # For ENVI use BSQ (will get this if we don't pass in creation options)
+ if driver.ShortName == 'ENVI':
+ # If there is no extension, use the driver name in lower case
+ driver_ext = driver.ShortName.lower()
+ self.gdal_ext_from_driver[driver.ShortName] = driver_ext
+ self.gdal_driver_from_ext[driver_ext] = driver.ShortName
+ # If they don't have an extension specified - skip
+ self.gdal_driver_from_ext.update(NON_GDAL_DRIVER_FROM_EXT)
+ def get_driver_from_ext(self, file_ext):
+ Get GDAL driver short name from file
+ :param file_ext: File extension (e.g., .bil)
+ # Remove '.' if there is one before the extension.
+ file_ext = file_ext.lstrip('.')
+ return self.gdal_driver_from_ext[file_ext]
+ raise KeyError('The driver for file extension {} could not be found'.format(file_ext))
+ def get_ext_from_driver(self, driver_name):
+ Get file extension from GDAL short
+ :param driver_name: Driver Name (e.g., GTiff)
+ return '.' + self.gdal_ext_from_driver[driver_name]
+ raise KeyError('The extension for driver {} could not be found'.format(driver_name))
+ def get_creation_options_from_ext(self, file_ext):
+ Get preferred GDAL creation options from file
+ :param file_ext: File extension (e.g., .bil)
+ # Remove '.' if there is one before the extension.
+ file_ext = file_ext.lstrip('.')
+ return GDAL_CREATION_OPTIONS[file_ext]
+ # If there are no creation options defined return an empty list
+ def get_creation_options_from_driver(self, driver_name):
+ Get preferred GDAL creation options from file
+ :param driver_name: Driver Name (e.g., GTiff)
+ file_ext = self.get_ext_from_driver(driver_name)
+ file_ext = file_ext.lstrip('.')
+ return GDAL_CREATION_OPTIONS[file_ext]
+ # If there are no creation options defined return an empty list
+ def get_all_gdal_extensions(self):
+ Get all available GDAL extensions
+ return self.gdal_driver_from_ext.keys()
+ def get_all_gdal_drivers(self):
+ Get all available GDAL drivers
+ return self.gdal_ext_from_driver.keys()
+ def zip_to_gdal_path(self, filepath):
+ Takes in a zip filepath and if the zip contains files
+ matching an extension known to GDAL, prepend '/viszip' to the path
+ so that they can be opened using GDAL without extraction.
+ Known issues - only returns the first matching file not all valid files
+ if zipfile.is_zipfile(filepath):
+ zip_file = zipfile.ZipFile(filepath)
+ for file_within_zip in zip_file.filelist:
+ file_ext = os.path.splitext(file_within_zip.filename)[-1].lstrip(".")
+ if file_ext in self.get_all_gdal_extensions():
+ filepath = "/vsizip/{0}/{1}".format(filepath,
+ file_within_zip.filename)
