map-machine/osm_reader.py
Sergey Vartanov 113741c72a OSM reader.
2015-07-28 12:49:32 +03:00

95 lines
3 KiB
Python

"""
Reading OpenStreetMap data from XML file.
Author: Sergey Vartanov
"""
def parse_node_full(text):
"""
Parse full node parameters using regular expressions: id, visible, version,
etc. For faster parsing use parse_node().
"""
m = re.match('id="(.*)" visible="(.*)" version="(.*)" changeset="(.*)" timestamp="(.*)" user="(.*)" uid="(.*)" lat="(.*)" lon="(.*)"', text)
if m:
return {'id': m.group(1), 'visible': m.group(2), 'changeset': m.group(3), 'timestamp': m.group(4), 'user': m.group(5), 'uid': m.group(6), 'lat': m.group(7), 'lon': m.group(8)}
else:
print 'Error node'
def parse_node(text):
"""
Parse just identifier, latitude, and longitude from node parameters.
"""
id = text[4:text.find('"', 6)]
lat_index = text.find('lat')
lon_index = text.find('lon')
lat = text[lat_index + 5:text.find('"', lat_index + 7)]
lon = text[lon_index + 5:text.find('"', lon_index + 7)]
return {'id': id, 'lat': lat, 'lon': lon}
def parse_way_full(text):
m = re.match('id="(.*)" visible="(.*)" version="(.*)" changeset="(.*)" timestamp="(.*)" user="(.*)" uid="(.*)"', text)
if m:
return {'id': m.group(1), 'visible': m.group(2), 'changeset': m.group(3), 'timestamp': m.group(4), 'user': m.group(5), 'uid': m.group(6)}
else:
print 'Error way'
def parse_way(text):
id = text[4:text.find('"', 6)]
return {'id': id}
def parse_tag(text):
v_index = text.find('v="')
k = text[3:text.find('"', 4)]
v = text[v_index + 3:text.find('"', v_index + 4)]
return k, v
def get_max_min(nodes):
maximum = Geo(nodes[0]['lon'], nodes[0]['lat'])
minimum = Geo(nodes[0]['lon'], nodes[0]['lat'])
for node in nodes:
if node['lat'] > maximum.lat: maximum.lat = node['lat']
if node['lat'] < minimum.lat: minimum.lat = node['lat']
if node['lon'] > maximum.lon: maximum.lon = node['lon']
if node['lon'] < minimum.lon: minimum.lon = node['lon']
return minimum, maximum
def parse_osm_file(file_name, silent=False):
if not silent:
print 'Reading OSM file ' + file_name
start_time = datetime.datetime.now()
node_map = {}
way_map = {}
input_file = open(file_name)
line = input_file.readline()
while line != '':
if line[:6] == ' <node':
if line[-3] == '/':
node = parse_node(line[7:-3])
node_map[node['id']] = node
else:
element = parse_node(line[7:-2])
element['tags'] = {}
elif line == ' </node>':
node_map[node['id']] = element
elif line[:5] == ' <way':
if line[-3] == '/':
way = parse_node(line[7:-3])
node_map[node['id']] = node
else:
element = parse_way(line[6:-2])
element['tags'] = {}
element['nodes'] = []
elif line[:6] == ' <tag':
k, v = parse_tag(line[7:-3])
element['tags'][k] = v
elif line[:5] == ' <nd':
element['nodes'].append(line[11:-3])
line = input_file.readline()
input_file.close()
if not silent:
print 'File readed in ' + \
str(datetime.datetime.now() - start_time) + '.'
return node_map, way_map