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Bugfixed and cleaned up _as_geojson method
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Lukas Müller committed Sep 10, 2019
1 parent f0c4560 commit 5fabd38
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Showing 4 changed files with 34 additions and 111 deletions.
1 change: 1 addition & 0 deletions Pipfile
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Expand Up @@ -7,6 +7,7 @@ name = "pypi"
geojson = ">=1.3.1"
requests = ">=2.20.0"
nose = ">=1.3.7"
shapely = ">=1.6.4"

[dev-packages]

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141 changes: 31 additions & 110 deletions overpass/api.py
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Expand Up @@ -8,7 +8,7 @@
import csv
import geojson
import logging
import code
from shapely.geometry import Polygon, Point
from io import StringIO
from .errors import (
OverpassSyntaxError,
Expand Down Expand Up @@ -193,117 +193,38 @@ def _as_geojson(self, elements):
for elem in elements:
elem_type = elem.get("type")
elem_tags = elem.get("tags")
if elem_type and elem_type == "node":
elem_geom = elem.get("geometry", [])
if elem_type == "node":
# Create Point geometry
geometry = geojson.Point((elem.get("lon"), elem.get("lat")))
elif elem_type and elem_type == "way":
points = []
geom = elem.get("geometry")
if geom:
for coords in elem.get("geometry"):
points.append((coords["lon"], coords["lat"]))
geometry = geojson.LineString(points)
elif elem_type and elem_type == "relation":
# initialize result lists
elif elem_type == "way":
# Create LineString geometry
geometry = geojson.LineString([(coords["lon"], coords["lat"]) for coords in elem_geom])
elif elem_type == "relation":
# Initialize polygon list
polygons = []
poly = []
points = []
# conditions
prev = "inner"
not_first = False

for pos in range(len(elem["members"])):
mem = elem['members'][pos]

# check whether the coordinates of the next member need to be reversed
# also sometimes the next member may not actually connect to the previous member, so if necessary,
# find a matching member
if points:
dist_start = (points[-1][0] - mem["geometry"][0]["lon"]) ** 2 + (
points[-1][1] - mem["geometry"][0]["lat"]) ** 2
dist_end = (points[-1][0] - mem["geometry"][-1]["lon"]) ** 2 + (
points[-1][1] - mem["geometry"][-1]["lat"]) ** 2
if dist_start == 0:
pass # don't need to do anything
elif dist_end == 0:
# flip the next member - it is entered in the wrong direction
mem["geometry"] = list(reversed(mem["geometry"]))
else:
# try flipping the previous member
dist_flipped_start = (points[0][0] - mem["geometry"][0]["lon"]) ** 2 + (
points[0][1] - mem["geometry"][0]["lat"]) ** 2
dist_flipped_end = (points[0][0] - mem["geometry"][-1]["lon"]) ** 2 + (
points[0][1] - mem["geometry"][-1]["lat"]) ** 2
if dist_flipped_start == 0:
# just flip the start
points = list(reversed(points))
elif dist_flipped_end == 0:
# both need to be flipped
points = list(reversed(points))
mem["geometry"] = list(reversed(mem["geometry"]))
else:
# no matches -- look for a new match
point_found = False
for i in range(pos + 1, len(elem['members'])):
if not point_found:
new_pt = elem['members'][i]
dist_start = (new_pt['geometry'][0]['lon'] - points[-1][0]) ** 2 + (
new_pt['geometry'][0]['lat'] - points[-1][1]) ** 2
dist_end = (new_pt['geometry'][-1]['lon'] - points[-1][0]) ** 2 + (
new_pt['geometry'][-1]['lat'] - points[-1][1]) ** 2

if dist_start == 0 or dist_end == 0:
point_found = True
# swap the order of the members -- we have found the one we want
elem['members'][pos], elem['members'][i] = elem['members'][i], \
elem['members'][pos]
# save this new point as mem
mem = elem['members'][pos]

if dist_end == 0:
mem['geometry'] = list(reversed(mem['geometry']))

# address outer values
if mem['role'] == 'outer':
if prev == "inner":
# start new outer polygon
points = []

if points == [] and not_first:
# append the previous poly to the polygon list
polygons.append(poly)
poly = []

for coords in mem["geometry"]:
try:
points.append([coords["lon"], coords["lat"]])
except:
code.interact(local=locals())

if points[-1] == points[0]:
# finish the outer polygon if it has met the start
poly.append(points)
points = []
# update condition
prev = "outer"

# address inner points
if mem['role'] == "inner":
for coords in mem["geometry"]:
points.append([coords["lon"], coords["lat"]])

# check if the inner is complete
if points[-1] == points[0]:
poly.append(points)
points = []
# update condition
prev = "inner"

not_first = True

# add in the final poly
polygons.append(poly)

if polygons != [[]]:
# First obtain the outer polygons
for member in elem.get("members", []):
if member["role"] == "outer":
points = [(coords["lon"], coords["lat"]) for coords in member.get('geometry', [])]
# Check that the outer polygon is complete
if points and points[-1] == points[0]:
polygons.append([points])
# Then get the inner polygons
for member in elem.get("members", []):
if member["role"] == "inner":
points = [(coords["lon"], coords["lat"]) for coords in member.get('geometry', [])]
# Check that the inner polygon is complete
if points and points[-1] == points[0]:
# We need to check to which outer polygon the inner polygon belongs
point = Point(points[0])
for poly in polygons:
polygon = Polygon(poly[0])
if polygon.contains(point):
poly.append(points)
break
# Finally create MultiPolygon geometry
if polygons:
geometry = geojson.MultiPolygon(polygons)
else:
continue
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1 change: 1 addition & 0 deletions requirements.txt
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Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
geojson>=1.3.1
requests>=2.8.1
nose>=1.3.7
shapely>=1.6.4
2 changes: 1 addition & 1 deletion setup.py
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Expand Up @@ -22,6 +22,6 @@
"Topic :: Scientific/Engineering :: GIS",
"Topic :: Utilities",
],
install_requires=["requests>=2.3.0", "geojson>=1.0.9"],
install_requires=["requests>=2.3.0", "geojson>=1.0.9", "shapely>=1.6.4"],
extras_require={"test": ["pytest"]},
)

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