Python script to find lat,lng within a geofence circle for csv posts exported from picodash.com

picodash_export_geofence.py

#!/usr/bin/python

import sys
import csv
from math import sin, cos, sqrt, atan2, radians

try:
	filename = sys.argv[1]
	geofence = sys.argv[2]
	lat = geofence.split(',')[0]
	lng = geofence.split(',')[1]
	radius = geofence.split(',')[2]
except:
	print "\nERROR: Please specify filename and geofence(lat,lng,radius)\n"	
	print "Usage:"
	print " $ picodash_export_geofence.py data.csv 45,-122,5000\n"
	print "- First param should be the csv file path"
	print "- Second param should be the geofence (lat,lng,radius)\n"	
	sys.exit(0)

new_data=[]
# open csv file to check geofence
with open(filename, 'r') as csvfile:
	csv_reader = csv.reader(csvfile)
	# iterate on all rows in csv
	for row_index,row in enumerate(csv_reader):
		# find the lat,lng column index
		if row_index == 0:
			LAT_COL_NUM = None
			LNG_COL_NUM = None
			for col_index,col in enumerate(row):
				if col == "lat":
					LAT_COL_NUM = col_index
				elif col == "lng":
					LNG_COL_NUM = col_index
			new_data.append(row)
			continue
		# check if lat,lng is within geofence
		post_lat = row[LAT_COL_NUM]
		post_lng = row[LNG_COL_NUM]
		if post_lat != '' and post_lng != '':

			R = 6373.0
			lat1 = radians(float(post_lat))
			lon1 = radians(float(post_lng))
			lat2 = radians(float(lat))
			lon2 = radians(float(lng))
			within = float(radius)
			dlon = lon2 - lon1
			dlat = lat2 - lat1
			a = sin(dlat / 2)**2 + cos(lat1) * cos(lat2) * sin(dlon / 2)**2
			c = 2 * atan2(sqrt(a), sqrt(1 - a))
			distance = R * c * 1000
			inside = "YES"
			if distance > within:
				inside = "NO"
			else:
				new_data.append(row)	
			print "Post #"+str(row_index)+ ": " +str(inside)+ " (" +str(distance) + ")"
		else:
			print "Post #"+str(row_index)+ ": NA"

new_filename = filename.replace('.csv','_geofence.csv')
with open(new_filename, 'w') as csvfile:
	csv_writer = csv.writer(csvfile, lineterminator='\n')	
	csv_writer.writerows(new_data)
	print "Updated CSV with location column: " + new_filename

This is a Python script to filter data within a geofence for posts exported from picodash.com

You have to specify the csv_filename and geofence (lat,lng,radius). The script will create a new csv with "_geofence" appended to filename.

Usage:
/usr/bin/python picodash_export_geofence.py <csv_filename> <lat,lng,radius>

Example:
/usr/bin/python picodash_export_geofence.py data.csv 45.23,-122.23,5000

where is the csv file of geofencing data?