opencoil-paracity/website/historical/geojson-csv/geojson2csv.py

57 lines
2.0 KiB
Python
Executable File

import json
import csv
import argparse
import sys
import os
def main(args):
fp = args['infile']
geojson_data = json.load(fp)
if geojson_data['type'] == 'FeatureCollection':
parse_feature_collection(geojson_data['features'], args['outfile'])
else:
print("Can currently only parse FeatureCollections, but I found ", geojson_data['type'], " instead")
def parse_feature_collection(features, outfile):
# Each feature from the feature collection is a Type: Feature, a bunch of properties, and geometry.
# We want to flatten those out
# create the csv writer object
csvwriter = csv.writer(outfile, lineterminator=os.linesep)
count = 0
# We'd like to save the first header we see, to maintain the exact same ordering, in case
# some features change their order (we can't rely on it!)
header = []
for feature in features:
if count == 0:
header = list(feature['properties'].keys())
# We're going to assume the feature is just a point for this stage
header.extend(['lng','lat'])
csvwriter.writerow(header)
count += 1
csvwriter.writerow(feature_to_row(feature, feature['properties'].keys()))
outfile.close()
def feature_to_row(feature, header):
l = []
for k in header:
l.append(feature['properties'][k])
if feature['geometry']['type'] != 'Point':
raise RuntimeError("Expecting point type, but got ", feature['geometry']['type'])
coords = feature['geometry']['coordinates']
assert(len(coords)==2)
l.extend(coords)
return l
if __name__ == "__main__":
parser = argparse.ArgumentParser(prog="geojson2csv.py",
description='Convert simple GeoJSONs to CSVs')
parser.add_argument('infile', nargs='?', type=argparse.FileType('r'), default = sys.stdin)
parser.add_argument('outfile', nargs='?', type=argparse.FileType('w'), default = sys.stdout)
pargs = parser.parse_args()
main(vars(pargs))