GeoDjango + PostGIS + DRF¶
david.kwast@scicrop.com¶
Technology Specialist @ https://SciCrop.com¶
https://davidkwast.github.io/slides/geodjango-postgis-drf¶
Dependências¶
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display.Code(filename='./Pipfile', language='toml')
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* Ubuntu 18.04
GDAL¶
a translator library for raster and vector geospatial data formats
Sistema Operacional¶
foo@bar:~$ apt install gdal-bin libgdal-dev
foo@bar:~$ gdalinfo --version
GDAL 2.2.3, released 2017/11/20
Pip(Env)¶
foo@bar:~$ pipenv install numpy
foo@bar:~$ export CPLUS_INCLUDE_PATH=/usr/include/gdal
foo@bar:~$ export C_INCLUDE_PATH=/usr/include/gdal
foo@bar:~$ pipenv install "gdal==2.2.3"
Python¶
from osgeo import gdal; gdal.UseExceptions() # type: ignore
from osgeo import ogr; ogr.UseExceptions() # type: ignore
PostgreSQL + PostGIS¶
Python¶
foo@bar:~$ pipenv install psycopg2-binary
SQL¶
CREATE EXTENSION POSTGIS;
- https://pypi.org/project/psycopg2-binary/
- The binary package is a practical choice for development and testing but in production it is advised to use the package built from sources.
- https://postgis.net/documentation/
foo@bar:~$ ls -l restgis/
total 16
drwxrwxr-x 3 kwast kwast 4096 mai 24 16:40 geoapi
-rw-rw-r-- 1 kwast kwast 0 mai 24 16:37 __init__.py
-rw-rw-r-- 1 kwast kwast 3091 mai 24 16:37 settings.py
-rw-rw-r-- 1 kwast kwast 749 mai 24 16:37 urls.py
-rw-rw-r-- 1 kwast kwast 391 mai 24 16:37 wsgi.py
foo@bar:~$ ls -l restgis/geoapi/
total 24
-rw-rw-r-- 1 kwast kwast 63 mai 24 16:40 admin.py
-rw-rw-r-- 1 kwast kwast 87 mai 24 16:40 apps.py
-rw-rw-r-- 1 kwast kwast 0 mai 24 16:40 __init__.py
drwxrwxr-x 2 kwast kwast 4096 mai 24 16:40 migrations
-rw-rw-r-- 1 kwast kwast 57 mai 24 16:40 models.py
-rw-rw-r-- 1 kwast kwast 60 mai 24 16:40 tests.py
-rw-rw-r-- 1 kwast kwast 63 mai 24 16:40 views.py
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settings.INSTALLED_APPS
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foo@bar:~$ python manage.py runserver
Watching for file changes with StatReloader
Performing system checks...
System check identified no issues (0 silenced).
May 25, 2019 - 02:29:36
Django version 2.2.1, using settings 'restgis.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
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HOST = 'http://127.0.0.1:8000'
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requests.get(f'{HOST}/api/test').json()
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display.Code(filename='./restgis/geoapi/api/test_api.py')
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display.Image(url=f'{URL_SLIDES}/img/shape_01.jpeg')
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shape_raw = requests.get(f'{URL_SLIDES}/shapes/shape_01.geojson').text
shape_raw
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shape = json.loads(shape_raw)
shape
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shape_geometry = shape['features'][0]['geometry']
shape_geometry
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Obter o centróide de um polígono¶
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requests.post(url=f'{HOST}/api/shape/centroid', json=shape_geometry).json()
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display.Code(filename='./restgis/geoapi/api/shape_centroid.py')
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display.Image(url=f'{URL_SLIDES}/img/satelite_01.jpeg')
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Cortar imagem de satélite¶
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%%time
response = requests.post(
url = f'{HOST}/api/shape/crop',
json = shape_geometry,
headers = {
'Accept': 'image/png',
}
)
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response.headers['Content-Type']
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In [16]:
response.content[:100]
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len(response.content)
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display.Image(data=response.content)
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./restgis/geoapi/api/shape_crop.py
from rest_framework.decorators import api_view
from rest_framework.response import Response
from django.conf import settings
import tempfile
import json
from pathlib import Path
import numpy as np
import rasterio
import rasterio.mask
from rasterio.vrt import WarpedVRT
# urls.py: path('api/shape/crop', shape_crop.view)
@api_view(['POST'])
def view(request):
...
...
input_geojson = json.loads(request.body)
tci_rasterio = rasterio.open(settings.DEMO_IMAGE_SATELITE_FS_PATH)
tci_rasterio_dataset = WarpedVRT(tci_rasterio, crs='EPSG:4326')
tci_array, tci_affine = rasterio.mask.mask(
tci_rasterio_dataset,
[input_geojson],
indexes = None,
crop = True,
all_touched = False,
invert = False,
nodata = 0, #np.nan,
filled = True,
pad = False,
)
tci_x_size, tci_y_size = tci_array.shape[2], tci_array.shape[1] # Z,Y,X
...
...
with tempfile.TemporaryDirectory() as tmpdirname:
tci_image_path = Path(tmpdirname).joinpath('tci.png')
with rasterio.open(
tci_image_path, 'w', driver='PNG',
dtype = 'uint8', count = 4,
width = tci_x_size, height = tci_y_size,
transform = tci_affine
) as tci_rast_fd:
tci_rast_fd.write(tci_array[0], 1)
tci_rast_fd.write(tci_array[1], 2)
tci_rast_fd.write(tci_array[2], 3)
tci_rast_fd.write(
np.asarray(
np.where(tci_array[0] > 0, 255, 0),
dtype = np.uint8
),
4
)
with open(tci_image_path ,'rb') as fd:
payload = fd.read()
return Response(payload, content_type='image/png')
Models¶
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display.Code(filename='./restgis/geoapi/models.py')
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foo@bar:~$ python manage.py makemigrations
Migrations for 'geoapi':
restgis/geoapi/migrations/0001_initial.py
- Create model Point
- Create model Polygon
foo@bar:~$ python manage.py migrate
Operations to perform:
Apply all migrations: auth, contenttypes, geoapi
Running migrations:
Applying contenttypes.0001_initial... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0001_initial... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying geoapi.0001_initial... OK
--
-- Create model Point
--
CREATE TABLE "geoapi_point" (
"id" serial NOT NULL PRIMARY KEY,
"name" varchar(100) NOT NULL UNIQUE,
"geometry" geometry(POINT,4326) NOT NULL
);
--
-- Create model Polygon
--
CREATE TABLE "geoapi_polygon" (
"id" serial NOT NULL PRIMARY KEY,
"name" varchar(100) NOT NULL UNIQUE,
"geometry" geometry(POLYGON,4326) NOT NULL
);
--
--
CREATE INDEX "geoapi_point_name_c7d56075_like" ON "geoapi_point" ("name" varchar_pattern_ops);
CREATE INDEX "geoapi_point_geometry_id" ON "geoapi_point"USING GIST ("geometry");
CREATE INDEX "geoapi_polygon_name_d010f373_like" ON "geoapi_polygon" ("name" varchar_pattern_ops);
CREATE INDEX "geoapi_polygon_geometry_id" ON "geoapi_polygon"USING GIST ("geometry");
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from restgis.geoapi import models
from django.contrib.gis import geos
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models.Point.objects.all().delete()
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models.Polygon.objects.all().delete()
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centroid_dict = requests.post(url=f'{HOST}/api/shape/centroid', json=shape_geometry).json()
centroid_dict
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centroid_obj = models.Point.objects.create(
name = 'centroid',
geometry = geos.Point(centroid_dict['coordinates']),
)
centroid_obj
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centroid_obj.name, centroid_obj.geometry
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centroid_obj.geometry.x
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centroid_obj.geometry.y
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shape_geometry
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polygon_obj = models.Polygon.objects.create(
name = 'shape',
geometry = geos.Polygon(shape_geometry['coordinates'][0]),
)
polygon_obj
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polygon_obj.geometry
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polygon_obj.geometry.area
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qs = models.Polygon.objects.filter(
geometry__contains=centroid_obj.geometry
)
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print(qs.query)
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qs[0].name
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display.Image(url=f'{URL_SLIDES}/img/sql_01.png')
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