def qgis_init(verbose=False):
''' qgis_init() - Initialize the QGIS application
Parameters
----------
verbose : bool, default=False
True = command-line output on
Returns
-------
qgs : QGIS instance object
'''
import qgis.core as qcore
import init_qgis_paths as init_qgis_paths
if verbose:
print(' Initializing QGIS')
app_path = init_qgis_paths()
qcore.QgsApplication.setPrefixPath(app_path, True) # Path to QGIS binary
# Create a reference to the QgsApplication, True = enables GUI (for applications)
qgs = qcore.QgsApplication([], True)
qgs.initQgis() # load providers
if verbose:
print(' QGIS Initialized')
return qgs
def make_qgis_project_file(path):
"""Create a QGIS project file with the correct stuff in it.
path: the desired path to .qgs project file, e.g.:
/luigi/data/qgreenland/qgreenland.qgs
Developed from examples:
https://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/intro.html#using-pyqgis-in-standalone-scripts
"""
# The qgis prefix path is two directories above the qgis executable.
# See:
# https://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/intro.html#using-pyqgis-in-standalone-scripts
qgis_path = subprocess.run(
['which', 'qgis'],
stdout=subprocess.PIPE).stdout.decode('utf-8').strip('\n')
qgis_prefix_path = os.path.abspath(os.path.join(qgis_path, '..', '..'))
# Boilerplate QGIS initialization code;
# - Suppresses "Application path not intialized" errors
# - Enables Qt support for fonts used in layer styles (labels)
qgs = qgc.QgsApplication([], False)
qgs.initQgis()
qgc.QgsApplication.setPrefixPath(qgis_prefix_path, True)
# Create a new project; initializes basic structure
project = qgc.QgsProject.instance()
project.write(path)
project_crs = qgc.QgsCoordinateReferenceSystem(CONFIG['project']['crs'])
project.setCrs(project_crs)
# Set the default extent. Eventually we may want to pull the extent directly
# from the configured 'map frame' layer.
view = project.viewSettings()
background_extent = CONFIG['project']['extents']['data']
extent = qgc.QgsReferencedRectangle(
qgc.QgsRectangle(*background_extent.values()), project_crs)
view.setDefaultViewExtent(extent)
_add_layers(project)
_add_decorations(project)
_set_groups_options(project)
_add_empty_groups(project)
# TODO: is it normal to write multiple times?
project.write()
# Release all file locks! If we don't do this, we won't be able to clean up
# layer source files after zipping the project.
project.clear()
def _setup_qgs_app() -> qgc.QgsApplication:
"""Set up QgsApplication.
This function should only be called once to instantiate a
QgsApplication. Once all pyqgis operations are complete, the QgsApplication
MUST be cleaned up with the QgsApplication instance's `exitQgis`
method. Failure to do so will result in a segmentation fault.
"""
qgis_prefix_path = _get_qgs_prefix_path()
# Boilerplate QGIS initialization code;
# - Suppresses "Application path not intialized" errors
# - Enables Qt support for fonts used in layer styles (labels)
qgs = qgc.QgsApplication([], False)
qgs.initQgis()
qgc.QgsApplication.setPrefixPath(str(qgis_prefix_path), True)
return qgs
def setUp(self):
self.app = core.QgsApplication([], True)
propertize(core)
Usage: run myproject.qgs /path/to/output
"""
if __name__ == "__main__":
import sys
import os
from qgis.PyQt.QtCore import QFileInfo
import qgis.core as Q
sys.path.append(os.path.dirname(__file__))
import main
qgs = Q.QgsApplication([], False)
qgs.initQgis()
project_path = sys.argv[1]
out_dir = sys.argv[2]
if not os.path.exists(project_path):
print project_path, 'not found'
sys.exit(1)
try:
os.mkdir(out_dir)
except OSError:
pass
print 'loading...'
import sys
import os
from qgis.core import QgsApplication
import qgis.core as qt
# Initialize QGIS
qt.QgsApplication.setPrefixPath("C:\\OSGeo4W64\\apps\\qgis", True)
qgs = qt.QgsApplication([], False)
qgs.initQgis()
# Add the path to processing
sys.path.append('C:\OSGeo4W64\apps\qgis\python\plugins')
# Import processing
import processing
def create_map(shp_file, csv_f):
assert os.path.exists(
shp_file
), "I could not locate the shape file. Was the path typed correctly?"
s = open(shp_file, 'r+')
print("Shape File Located")
# Add Georgia Map to Canvas
ga_map = qt.QgsVectorLayer(shp_file, "GA Map", "ogr")
qt.QgsProject.instance().addMapLayer(ga_map)
s.close()
csv_uri = csv_f + "?encoding=UTF-8&delimiter=,"
group_name="CHM 2011",
style_file="D:/Lb/Maps/QGIS_styles/CHM.qml")
# Get list of files
in_files = [f for f in os.listdir(a.RSDS_folder) if f.endswith(a.file_ext)]
if len(in_files) > 0:
# Get full file paths
in_paths = [os.path.join(a.RSDS_folder, f) for f in in_files]
# Get names of layers
in_names = [os.path.splitext(f)[0] for f in in_files]
# Launch QGIS application
qgs = qc.QgsApplication([], True)
qgs.initQgis()
# WARNING: This is to silence the ol 'Sum of Photometric type-related... (etc)' error
# Should be included with caution, since it can silence other errors
PushErrorHandler('CPLQuietErrorHandler')
# Create new project
project = qc.QgsProject()
# Read map
project.read(a.qgs_file)
# To access layers and groups at root
root = project.layerTreeRoot()
def _init_qgis():
qgs = qgc.QgsApplication([], False)
qgs.initQgis()
qgc.QgsApplication.setPrefixPath(_get_prefix_path(), True)
