Don't worry, that what the forum is all about... to help one another.
Have a look at the code below. The majority is placed inside a function "MergePolygonsOnDate". The main function (lines 13 - 23) contains the logic for looping through your featureclasses. It will create a list of all the featureclasses in you workspace. Based on the input name it will create the new output names. On line 23 for each featureclass the "MergePolygonsOnDate" is called. I haven't tested the code, so if you run into problems, just post it and I'll have a look.
#-------------------------------------------------------------------------------
# Name: MergePolygonsOnDate_v3.py
# Purpose: Merge polygons on date range
#
# Author: xbakker
#
# Created: 19/08/2014
#-------------------------------------------------------------------------------
import arcpy, os
from datetime import datetime, timedelta
def main():
# specify the workspace
ws = r"C:\Users\PaulBritten\Desktop\tenure\All reserves"
arcpy.env.workspace = ws
arcpy.env.overwriteOutput = True
lst_fc = arcpy.ListFeatureClasses()
for fc in lst_fc:
name, ext = os.path.splitext(fc)
fc_out = "{0}_merged{1}".format(name, ext)
MergePolygonsOnDate(os.path.join(ws, fc), os.path.join(ws, fc_out))
def MergePolygonsOnDate(fc, fc_out):
# change settings
fld_start = "DateFrom" # create date field and fill it with content of StartDate
fld_end = "DateTo" # create date field and fill it with content of EndDate
fld_name = "Name"
fld_outname = "OutputName" # output name
len_outname = 75
# create empty output shapefile
ws_path, fc_out_name = os.path.split(fc_out)
arcpy.CreateFeatureclass_management(ws_path, fc_out_name,
"POLYGON", fc, "SAME_AS_TEMPLATE", "SAME_AS_TEMPLATE", fc)
# add string field
arcpy.AddField_management(fc_out, fld_outname, "TEXT", "", "", len_outname)
flds = ("SHAPE@", fld_start, fld_end, fld_name)
flds_out = ("SHAPE@", fld_start, fld_name, fld_outname)
# create a unique list of dates from start date
lst_dates = list(set([row[0] for row in arcpy.da.SearchCursor(fc, (fld_start))]))
lst_dates.sort()
# insert cursor to store features to new featureclass
with arcpy.da.InsertCursor(fc_out, (flds_out)) as curs_out:
# loop through list of unique dates
for date in lst_dates:
# create an expression
expression = "{0} <= date '{2}' AND {1} >= date '{2}'".format(
arcpy.AddFieldDelimiters(fc, fld_start),
arcpy.AddFieldDelimiters(fc, fld_end), date)
i = 0
# create the searchcursor with the expression
with arcpy.da.SearchCursor(fc, flds, where_clause=expression) as curs:
for row in curs:
pol = row[0]
name = row[3] # take name of first polygon
if i == 0:
# first polygon is just the polygon"
polygon = pol
else:
# next polygons are added with union
polygon = polygon.union(pol)
i += 1
# insert the feature into the output featureclass
datefrom = date
i_date = lst_dates.index(date)
if i_date + 1 > len(lst_dates) - 1:
dateto = ""
outname = "{0} {1} - {2}".format(name, datefrom.strftime('%Y/%m/%d'), dateto)
else:
dateto = lst_dates[i_date + 1] - timedelta(days=1)
outname = "{0} {1} - {2}".format(name, datefrom.strftime('%Y/%m/%d'), dateto.strftime('%Y/%m/%d'))
curs_out.insertRow((polygon, row[1], name, outname))
if __name__ == '__main__':
main()
