arcpy_delimiters.py

"""
    First, this was written back when I wrote Python a bit more like C - I know it needs some work! But for setting delimiters,
    you can do the following:
    
    my_dataset = data_file(r"path_to_data")
    my_dataset.delim_open  # gives you the opening delimeter
    my_dataset.delim_close  # gives you the closing delimeter
"""

import logging

delims_open = {'mdb': "[", "sqlite": "\"", 'gdb': "\"", 'shp': "\"", 'in_memory': ""}  # a dictionary of field delimiters for use in sql statements.
delims_close = {'mdb': "]", "sqlite": "\"", 'gdb': "\"", 'shp': "\"", 'in_memory': ""}  # in one type of field or another. These two are just extension based lookups

processing_log = logging.getLogger("processing_log")

class geospatial_object:

	def setup_object(self):
		'''like __init__ but won't be overridden by subclasses'''

		if 'setup_run' in self.__dict__:  # check if we have this key in a safe way
			if self.setup_run is True:  # have we already run this function
				return  # don't run it again

		self.setup_run = True
		self.gdb = None
		self.temp_folder = None
		self.temp_gdb = None

	def check_temp(self):
		self.setup_object()

		if not self.temp_folder or not self.temp_gdb:
			try:
				self.temp_folder = tempfile.mkdtemp()
				temp_gdb = os.path.join(self.temp_folder,"join_temp.gdb")
				if arcpy.Exists(temp_gdb):
					self.temp_gdb = temp_gdb
				else: # doesn't exist
					if 'log' in sys.modules:
						processing_log.info("Creating %s" % temp_gdb)
					arcpy.CreateFileGDB_management(self.temp_folder,"join_temp.gdb")
					self.temp_gdb = temp_gdb
			except:
				return False
		return True

	def get_temp_folder(self):
		self.setup_object()

		if self.check_temp():
			return self.temp_folder
		else:
			raise IOError("Couldn't create temp folder")

	def get_temp_gdb(self):
		self.setup_object()

		if self.check_temp():
			return self.temp_gdb
		else:
			raise IOError("Couldn't create temp gdb or folder")
			

class data_file(geospatial_object):
	def __init__(self,filename = None):
		self.data_location = filename
		self.delim_open = None
		self.delim_close = None

	def set_delimiters(self):

		processing_log.info("Setting delimiters",)

		try:
			fc_info = arcpy.ParseTableName(self.data_location)
			database, owner, featureclass = fc_info.split(",")
		except:
			processing_log.error("Failed to assess data format")
			return False

		processing_log.info("Type from ParseTableName = %s" % featureclass)

		if re.match(" mdb",featureclass) is not None or re.search("\.mdb",featureclass) is not None:
			self.delim_open = delims_open['mdb']
			self.delim_close = delims_close['mdb']
		elif re.match(" gdb",featureclass) is not None or re.search("\.gdb",featureclass) is not None:
			self.delim_open = delims_open['gdb']
			self.delim_close = delims_close['gdb']
		elif re.match(" shp",featureclass) is not None or re.search("\.shp",featureclass) is not None:
			self.delim_open = delims_open['shp']
			self.delim_close = delims_close['shp']
		elif re.match(" sqlite", featureclass) is not None or re.search("\.db", featureclass) is not None or re.search("\.sqlite", featureclass) is not None:
			self.delim_open = delims_open['sqlite']
			self.delim_close = delims_close['sqlite']
		elif re.match(" in_memory",featureclass) is not None or re.search("in_memory",featureclass) is not None: # dbmses use no delimeters. This is just a guess at how to detect if an fc is in one since I don't have access yet.
			self.delim_open = delims_open['in_memory']
			self.delim_close = delims_close['in_memory']
		elif re.match(" sde",featureclass) is not None:  # dbmses use no delimeters. This is just a guess at how to detect if an fc is in one since I don't have access yet.
			self.delim_open = ""
			self.delim_close = ""
		else:
			processing_log.warning("No field delimiters for this type of data. We can select features in gdbs, mdbs, shps, in_memory, and possibly sde files (untested)")
			return False

		return True