Scripting (Python) Feature Class content into Shapefiles following an UTM data structure

Question

Consider a Feature Class and two of its fields are "UTM_grid" and the "OID".

Scripting with python 2.7 for ArcGIS 10.3.

"UTM_grid" field contains the geographic info (e.g. B1SD40B) and was broken down into "UTM_block" + "UTM_sheet" (B1 + SD40B) and then using a dictionary and list structure UTM_block-->UTM_sheet-->OID was organized with this syntax:

{ 'UTM_block_1' : { 'UTM_sheet_A' : [ oid_1 , oid_2 ] }, { UTM_sheet_2 : [ oid_3 , oid_4, oid_5 ] } }

We need to create shapefiles with features (identified by the object value - oid) based on the follow data structure (OIDs will be organized regarding an UTM/location based structure):

• UTM_block_* will be a folder
• UTM-sheet_* its subfolder.
• List of objects (OIDs) will populate the shapefile.

Note: Features Classes to export are in a SDE geodatabase. We read/list the FCs in that GDB and for each FC we need to process the export of its features by UTM block-sheet into shapefiles. Looking at the fields "UTM_grid" and "ObjectID" we check while sheet ( utm_grid[1] ) = "foo", read the corresponding OID, and put the Feature into a Shapefile inside the (sub)folder (which has the associated sheet name). The same logic could be used to organize sheets inside the block folders.

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Another point we have to deal with is that the shapefile should only have some fields of the original Feature Class:

We have used fieldmappings and arcpy.FeatureClassToFeatureClass_conversion() to create a non-UTM-organized shapefile from a Feature Class with the fields that we need.

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Now the problem is how to process the feature export to get UTM-organized shapefiles! How can we manage it?

Bellow is what we have now inside a function:

with arcpy.da.SearchCursor(feature_class, ['UTM_grid' , 'OBJECTID']) as cursor:
    dic = dict()
    for row in cursor:
        UTM_sheet_value = row[0]
        oid_value = row[1]

        try:
            b_s_split = UTM_sheet_value.split('_') # split of block & sheet

        except Exception, e:
            pass
            print(UTM_sheet_value)
            print(e)

        else:
            dic.setdefault( b_s_split[0], {} ).setdefault( b_s_split[1], [] ).append( oid_value )

            # create folders & subfolders (blocks & sheets) in a directory
            dir_path = os.path.dirname("E:\\")
            dirs = [ [b_s_split[0]] , [b_s_split[1]] ]

            for item in itertools.product(*dirs):
                if not os.path.isdir(os.path.join(dir_path, *item)):
                    os.makedirs(os.path.join(dir_path, *item))

Answer 1

You could try something like this:

import os
import arcpy



arcpy.env.overwriteOutput = 1

output_folder = r"full_path_to_folder"

fc = r"full_path_to_feature_class"

fields = ["OID@","SHAPE@","UTM_GRID"] #modify as required

template_fc = r"full_path_to_template_schema" #with fields you want to keep - they should also be in the field list above

fc_data = dict([(row[0],(row[1],row[2])) for row in arcpy.da.SearchCursor(fc,fields)]) # read data from feature class, objectid as key, shape and utm_grid as value list

utm_dict = {}

for k,v in fc_data.iteritems():
    block_sheet = v[1].split("_")
    utm_dict.setdefault(block_sheet[0],{}).setdefault(block_sheet[1],[]).append(k)


for block, sheets in utm_dict.iteritems():

    sheet_folders = [os.path.join(output_folder,block,sheet_key) for sheet_key in sheets.keys()]#create folders for each block, with sheets as subfolders
    for sf in sheet_folders:
        if not os.path.exists(sf):
            os.makedirs(sf)

        sheet_id = os.path.basename(sf)
        sheet_shapefile = os.path.join(sf,"{0}.shp".format(sheet_id))

        if arcpy.Exists(sheet_shapefile):
            arcpy.Delete_management(sheet_shapefile)
        arcpy.CreateFeatureclass_management(sf,sheet_id,"POLYGON",template_fc)

        sheet_cursor = arcpy.da.InsertCursor(sheet_shapefile, fields)
        sheet_rows = [(i,fc_data[i][0],fc_data[i][1]) for i in sheets[sheet_id]]
        for sr in sheet_rows:
            sheet_cursor.insertRow(sr)

        del sheet_cursor

Answer 2

Solution:

fd_temp_path = "\\path\\to\\dataset"
shp_dir = "\\path\\to\\shp_dir"
if not os.path.exists(shp_dir):
    os.makedirs(shp_dir)
# list FC in dataset "TEMP" in a SDE
fc = arcpy.ListFeatureClasses(feature_dataset="TEMP")

for fc in sorted(fc_mapped):
    fc_mapped_path = os.path.join(fd_temp_path, fc)
    basename = fc_mapped_path.rsplit('.', 1)[-1]

    # FOL_250K/UTM values 
    utm_field = "FOL_250K"
    sql_prefix = "DISTINCT {}".format(utm_field)
    sql_suffix = None
    distinct_utm = [ i[0] for i in arcpy.da.SearchCursor(fc_mapped_path, utm_field, sql_clause=(sql_prefix, sql_suffix) ) ]

    # folders & export by utm values  
    for utm in distinct_utm:
        if utm[0] is None:
            print("FOL_250K empty")
            pass
        else:
            delim = "_"
            utm_parse = utm.split(delim, 1)
            print("utm_parse: ")
            print(utm_parse)

            if len(utm_parse) == 2:
                block, sheet = utm_parse  
                sheet_path = os.path.join(shp_dir, block, sheet)  
                if not os.path.exists(sheet_path):  
                    os.makedirs(sheet_path)
                arcpy.FeatureClassToFeatureClass_conversion(  
                    fc_mapped_path,  ## in_features  
                    sheet_path,  ## out_path  
                    "{}_{}_{}".format(block, sheet, basename),  ## out_name  
                    "FOL_250K = '{}'".format(utm)  ## where_clause  
                )
            else:
                raise ValueError("Parse {} was not possible with {}".format(utm, delim))