Thank you for the explanation and the picture. I think I now have a much better understanding of your needs. I've created another version of the script. Unfortunately I'm a little short on time and don't have time to test it. If you could let me know what errors pop up, we can fix the script as needed.
import arcpy
arcpy.env.overwriteOutput = True
#set feature classes:
inFC=r'C:\Path\To\Poly.shp'
tempGrid=r'C:\Path\To\tempGrid.shp' #just a temporary file
outFC=r'C:\Path\To\grid.shp' #final grid
#set number of desired cells:
x=100
#set ID field in the input feature class:
idField="ParentID" #set to a field you can use to identify with original record each grid was part of *MUST BE UNIQUE
#get shape field
shapeName = arcpy.Describe(inFC).shapeFieldName
#delete tempGrid if exists:
if arcpy.Exists(tempGrid):
arcpy.Delete_management(tempGrid)
#delete outFC if exists:
if arcpy.Exists(outFC):
arcpy.Delete_management(outFC)
#Create output FC (the where statement will select 0 records
arcpy.Select_analysis(inFC, outFC, '"'+idField+'" <> "'+idField+'"') #change double quotes "" to [] if using geodatabases
rows=arcpy.da.SearchCursor(idField,shapeName)
for row in rows:
where='"'+idField+'" = \''+row.getValue(idField)+'\'' #change double quotes "" to [] if using geodatabases
#Use this line if your idField is a number: where='"'+idField+'" = '+str(row.getValue(idField)) #change double quotes "" to [] if using geodatabases
arcpy.MakeFeatureLayer_management(inFC, "master_lyr",where)
feat = row.getValue(shapeName)
#set default grid variables:
extent = feat.extent
origin_coord=str(extent.XMin)+" "+str(extent.YMin)
oppositeCoorner=str(extent.XMax)+" "+str(extent.YMax)
y_axis_coord=str(extent.XMin)+" "+str(extent.YMin+10)
number_rows=number_columns=0
geometryType = 'POLYGON'
#set starting cellSize and increment:
cellSize=max(float(extent.width),float(extent.height))
inc=cellSize
countOutFC=0.0 #needed to start while loop
#Find an appropriate cell size:
while countOutFC!=x:
if cellSize==inc:
inc=inc/2.0
continue
cell_width=cell_height=cellSize
arcpy.CreateFishnet_management(tempGrid,origin_coord,y_axis_coord,cell_width,cell_height,number_rows,number_columns,oppositeCoorner,"LABELS","#",geometryType)
arcpy.MakeFeatureLayer_management(tempGrid, "temp_lyr")
arcpy.SelectLayerByLocation_management("temp_lyr", "INTERSECT", "master_lyr")
countOutFC=float(arcpy.GetCount_management("temp_lyr").getOutput(0))
print "Cell size: "+str(cellSize)+" Count: "+str(countOutFC)
if countOutFC>x:
print "Overshot..."
cellSize=prevCellSize
inc=inc/2.0
else:
prevCellSize=cellSize
cellSize-=inc
cellSize=prevCellSize
print '\nFound an appropriate cell size: '+str(cellSize)
#Find a simplified cell size:
print "\nTrying to simplify..."
for i in range(len(str(cellSize))):
simpCellSize=round(cellSize,i)
if simpCellSize==0:
continue
cell_width=cell_height=simpCellSize
arcpy.CreateFishnet_management(tempGrid,origin_coord,y_axis_coord,cell_width,cell_height,number_rows,number_columns,oppositeCoorner,"LABELS","#",geometryType)
arcpy.MakeFeatureLayer_management(tempGrid, "temp_lyr")
arcpy.SelectLayerByLocation_management("temp_lyr", "INTERSECT", "master_lyr")
countOutFC=float(arcpy.GetCount_management("temp_lyr").getOutput(0))
print "Cell size: "+str(simpCellSize)+" Count: "+str(countOutFC)
if countOutFC==x:
break
if simpCellSize==cellSize:
print "Could not easily find a simplified cell size."
#rerun for last good cellsize (not simplified):
cell_width=cell_height=cellSize
arcpy.CreateFishnet_management(tempGrid,origin_coord,y_axis_coord,cell_width,cell_height,number_rows,number_columns,oppositeCoorner,"LABELS","#",geometryType)
arcpy.MakeFeatureLayer_management(tempGrid, "temp_lyr")
arcpy.SelectLayerByLocation_management("temp_lyr", "INTERSECT", "master_lyr")
else:
print "A simplified cell size: "+str(simpCellSize)
arcpy.Append_management("master_lyr",outFC)
del rows
print "Done!!!"
