Importowanie przetwarzania QGIS w autonomicznym skrypcie python?

Chcę napisać kilka samodzielnych skryptów korzystających z przybornika przetwarzania Qgis.

Przeczytałem kilka wątków (np. Tu i tutaj ), ale nie mogłem znaleźć działającego rozwiązania.

Korzystanie z Qgis 2.16.1 na Ubuntu Xenial 16.04 LTS

Sekcja importu mojego skryptu wygląda następująco:

# Python modules
import sys
import time
import os

# Qgis modules
from qgis.core import *
import qgis.utils
from PyQt4.QtCore import QFileInfo, QSettings

Czy ktoś wie, czego mi brakuje, aby móc zaimportować moduł przetwarzania?

Dzięki prostemu przetwarzaniu importu otrzymuję to:

Original exception was:
Traceback (most recent call last):
 File "/home/steph/Documents/Projets/20141227-CIM_Bishkek/Scripts/python/00-projets/20160811-AnalysesUAVs/20160811-UAVAnalyse.py", line 36, in <module>
import processing
 File "/usr/lib/python2.7/dist-packages/qgis/utils.py", line 607, in _import
mod = _builtin_import(name, globals, locals, fromlist, level)
ImportError: No module named processing

EDYCJA (po komentarzu Josepha)

Próbowałem tak:

# Python modules
import sys
import time
import os

# Qgis modules
from qgis.core import *
import qgis.utils
from PyQt4.QtGui import *
app = QApplication([])
QgsApplication.setPrefixPath("/usr", True)
QgsApplication.initQgis()
from PyQt4.QtCore import QFileInfo, QSettings
#from PyQt4.QtGui import *

# Prepare processing framework 
sys.path.append('/home/steph/.qgis2/python/plugins')
from processing.core.Processing import Processing
Processing.initialize()
from processing.tools import *

ale zachowanie jest dziwne: mój skrypt działa do końca bezbłędnie, ale wydaje się, że „przeskakuje” zadania, które ma wykonać :-) Innymi słowy, działa do końca, ale nic nie robi.

Przyznaję, że moje wyjaśnienie nie jest bardzo jasne ... Zbadam dalej, ale jeśli ktoś ma magiczne rozwiązanie (a nie obejście), aby zaimportować ten moduł, proszę!

EDYCJA 2: dodając cały mój skrypt. Przepraszam, jeśli to trochę długo ....

# -*- coding: cp1252 -*-
########################################################
## Name: Performs various analyses on UAV imagery using Qgis
## Source Name: UAVanalyse.py
## Version: Python 2.7
## Author: Stephane Henriod
## Usage: Performs a set of analyses on UAV imagery
## Date 11.08.2016
## Modified: 
########################################################


# Import required modules

# Python modules
import sys
import time
import os

# Qgis modules
from qgis.core import *
import qgis.utils
from PyQt4.QtCore import QFileInfo, QSettings

# Custom modules
from config_work import *
import display_msg as disp
import clean_time as cl

def make_raster_layer(raster, log_file):
    """Creates a raster layer from the path to a raster, if the path exists and if the raster is valid

    Param_in:
        raster (string) -- The path to the raster to be transformed into a layer
        log_file (string) -- The path to the log file to write in

    Param_out:
        list: 
            [0] = full path to the raster 
            [1] = raster layer

    """

    if os.path.exists(raster):
        fileName = raster
        fileInfo = QFileInfo(fileName)
        baseName = fileInfo.baseName()
        rlayer = QgsRasterLayer(fileName, baseName)
        if rlayer.isValid():
            return [raster, rlayer]
    else:
        return False

def study_raster(rlayer, log_file):
    """Returns properties of a raster, if this one exists and is valid

    Param_in:
        rlayer (bin) -- A raster layer
        log_file (string) -- The path to the log file to write in

    """

    infos = {}

    if rlayer:
        infos['a - Width'] = rlayer.width()
        infos['b - Height'] = rlayer.height()
        infos['c - Extent'] = rlayer.extent().toString()
        infos['d - # bands'] = rlayer.bandCount()
        infos['e - X resolution'] = rlayer.rasterUnitsPerPixelX()
        infos['f - Y resolution'] = rlayer.rasterUnitsPerPixelY()
        return infos
    else:
        return False


def project_raster(raster, to_crs, log_file):
    """Projects a raster into another crs

    Param_in:
        raster (string) -- The path to the raster to be transformed into a layer
        to_crs (string) -- The coordinate reference system to which the layer must be projected
        log_file (string) -- The path to the log file to write in

    """

    img_out_name = os.path.splitext(os.path.basename(raster))[0] + '_proj' + os.path.splitext(os.path.basename(raster))[1]
    img_out = os.path.join(output_folder, img_out_name)
    #processing.runalg("gdalwarp -overwrite -s_srs EPSG:32642 -t_srs " + to_crs + " " + rlayer[0] + " " + img_out)

    msg = img_out    
    disp.display_msg(log_file, msg, 'a')

    return img_out_name

if __name__ == "__main__":
    t_start_script = time.localtime()
    t_start_script_clean = time.strftime("%Y%m%d-%H%M", t_start_script)

    # Checking the folders
    if not os.path.exists(input_folder_path):
        os.makedirs(input_folder_path)
    if not os.path.exists(temp_folder_path):
        os.makedirs(temp_folder_path)
    if not os.path.exists(output_folder_path):
        os.makedirs(output_folder_path)

    # Creating the output and temp folders
    output_folder = os.path.join(output_folder_path, t_start_script_clean + '-UAVanalyse')
    temp_folder = os.path.join(temp_folder_path, t_start_script_clean + '-UAVanalyse')

    if not os.path.exists(output_folder):
        os.makedirs(output_folder)
    if not os.path.exists(temp_folder):
        os.makedirs(temp_folder)

    # Creating the log file
    log_file_name = t_start_script_clean + '-UAVanalyse.log'
    log_file = os.path.join(output_folder, log_file_name)

    # Heading of the log file
    msg = "Performs a set of analyses on UAV imagery" + os.linesep
    msg += "Input folder: " + input_folder_path
    msg += "\n RGB image: " + img_rgb_name
    msg += "\n NIR image: " + img_nir_name
    msg += "\n RGBIR image: " + img_rgbir_name
    msg += "\n DSM file: " + img_dsm_name
    disp.display_msg(log_file, msg, 'w')

    #msg = "Script started on " + cl.clean_time(t_start_script)
    #disp.display_msg(log_file, msg, 'a')


    # Initialize Qgis (source: http://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/intro.html)
    msg = 'Initialize Qgis'
    disp.display_msg(log_file, msg, 'a')
    # supply path to qgis install location
    QgsApplication.setPrefixPath("/usr", True)

    # create a reference to the QgsApplication, setting the
    # second argument to False disables the GUI
    qgs = QgsApplication([], False)

    # load providers
    qgs.initQgis()


    # Write your code here to load some layers, use processing algorithms, etc.

    # Make raster layers
    rlayer_rgb = make_raster_layer(img_rgb, log_file)
    rlayer_nir = make_raster_layer(img_nir, log_file)
    rlayer_rgbir = make_raster_layer(img_rgbir, log_file)
    rlayer_dsm = make_raster_layer(img_dsm, log_file)

    all_valid_layers = []
    if rlayer_rgb: all_valid_layers.append(rlayer_rgb)
    if rlayer_nir: all_valid_layers.append(rlayer_nir)
    if rlayer_rgbir: all_valid_layers.append(rlayer_rgbir)
    if rlayer_dsm: all_valid_layers.append(rlayer_dsm)




    # (I) Infos about the layers
    msg = os.linesep + frm_separator + os.linesep + '(I) Infos about the layers' + os.linesep + frm_separator + os.linesep
    disp.display_msg(log_file, msg, 'a')

    i = 1
    for layer in all_valid_layers:
        infos = study_raster(layer[1], log_file)
        msg = '\n (' + str(i) + ') ' + layer[0] + os.linesep
        for item in sorted(infos):
            msg += '\n ' + str(item) + ': ' + str(infos[item]) + os.linesep

        i+=1
        disp.display_msg(log_file, msg, 'a')

    msg = 'List of valid layers:' + os.linesep
    for layer in all_valid_layers:
        msg += layer[0]+ os.linesep
    disp.display_msg(log_file, msg, 'a')


    # (II) Projects the layers into the national coordinate system or any desired system
    msg = os.linesep + frm_separator + os.linesep + '(II) Projecting of the layers' + os.linesep + frm_separator + os.linesep
    disp.display_msg(log_file, msg, 'a')

    i = 1
    for layer in all_valid_layers:
        project_raster(layer[0], to_crs, log_file)




    # When script is complete, call exitQgis() to remove the provider and
    # layer registries from memory
    qgs.exitQgis()
    msg = 'Qgis has been closed'
    disp.display_msg(log_file, msg, 'a')

    #raw_input("Press Enter to continue...")

Linux QGIS 2.18.1

Po otrzymaniu tego kodu uruchom Przetwarzanie z niezależnego skryptu:

#!/usr/bin/env python
import qgis
from qgis.core import *
import sys

app = QgsApplication([],True, None)
app.setPrefixPath("/usr", True)
app.initQgis()
sys.path.append('/usr/share/qgis/python/plugins')
from processing.core.Processing import Processing
Processing.initialize()
from processing.tools import *

print Processing.getAlgorithm("qgis:creategrid")

Udało mi się to uruchomić, dziękuję @Joseph za wskazówki:

# Import required modules

# Python modules
import sys
import time
import datetime
import os
from getpass import getuser

# Qgis modules and environment
from qgis.core import *
import qgis.utils
from PyQt4.QtCore import QFileInfo, QSettings

from PyQt4.QtGui import QApplication
app = QApplication([])

QgsApplication.setPrefixPath("/usr", True)
QgsApplication.initQgis()

# Prepare processing framework
sys.path.append('/home/' + getuser() + '/.qgis2/python/plugins')
from processing.core.Processing import Processing

Processing.initialize()

I mogę to przetestować

print Processing.getAlgorithm("qgis:creategrid")

Wydaje mi się, że mój problem wynika z faktu, że zaimportowałem moduły na początku skryptu, a następnie próbowałem utworzyć obkekty Qgi z funkcji. Myślę, że byłoby to również możliwe, ale prawdopodobnie moje umiejętności w Pythonie są wadliwe.

Teraz spróbuję ustawić moduł przetwarzania :-)