使用Python将csv导入QGIS

Question

I am attempting to import a file into QGIS using a python script. I'm having a problem getting it to accept the CRS. Code so far

from PyQt4.QtGui import * from PyQt4.QtCore import * from qgis.core import * from qgis.utils import iface

----1 Set file name here

InFlnm='Input.CSV'

---2 Set pathname here

InDrPth='G:/test'

---3 Build the file name and path for uri

InFlPth="file:///"+InDrPth+InFlnm

---4 Set import Sting here note only need to set x and y others come for free!

uri = InFlPth+"?delimiter=%s&xField=%s&yField=%s" % (",","x","y")

---5 Load the points into a layer

bh = QgsVectorLayer(uri, InFlnm, "delimitedtext")

---6 Set the CRS (Not sure if this is working seems to?)

bh.setCrs(QgsCoordinateReferenceSystem(32365, QgsCoordinateReferenceSystem.EpsgCrsId)

---7 Display the layer in QGIS (Here I get a syntax error?)

QgsMapLayerRegistry.instance().addMapLayer(bh)

Now all the above works OK and QGIC prompts me for a CRS before executing the last line of the script to display the layer - as long as I comment-out step 6

However, if a attempt to set the CRS removing ### from step 6 I get a syntax error reporting on the last line that displays the points (Step 7). Note sure what the trick is here - I'm pretty new to Python but know my way around some other programming lagnuages

Answer 1

I found the answer to the final part of the problem at http://www.purplelinux.co.nz/ . I seems you need to suppress the form that prompts for the CRS. So the my script now looks like

#--- Load a csv file and set CRS
#---1 Reference library
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from qgis.core import *
from qgis.utils import iface

#---  2 Turn of the CRS dialog box
s = QSettings()
oldValidation = s.value( "/Projections/defaultBehaviour")
s.setValue( "/Projections/defaultBehaviour", "useGlobal" )

#--- 3 Set file name here
InFlnm='Test.csv'

#--- 4  Set pathname here
InDrPth='C:/_Work/PyQGIS/Test/'

#--- 5 Build file name an path for uri
InFlPth="file:///"+InDrPth+InFlnm

#---  6 Set import Sting here note only need to set x and y other come for free
uri = InFlPth+"?delimiter=%s&xField=%s&yField=%s" % (",","x","y")

#--- 7 Load point layer
bh = QgsVectorLayer(uri, InFlnm, "delimitedtext")

#--- 8 Confirm something is loaded and valid
bh.isValid()

#--- 9 Set CRS
bh.setCrs(QgsCoordinateReferenceSystem(32365, QgsCoordinateReferenceSystem.EpsgCrsId))

#--- 10 Display the layer into QGIS (but it asks for CRS before displaying_
QgsMapLayerRegistry.instance().addMapLayer(bh)

#--- 11 turn CRS dialog box back on again
s.setValue( "/Projections/defaultBehaviour", oldValidation )

The imported points now display but I'm getting an error stating that the CRS is not recognised so suspect step 9 above is not working. I will post again if I can crack this problem otherwise I may have to be happy with the CRS default perhaps.

Answer 2

Thanks for the import example, really helpful for a geocoder python script I want to output a csv from into qgis. To solve your problem, add the crs in your uri line:

uri = InFlPth+"?crs=epsg:32365&delimiter=%s&xField=%s&yField=%s" % (",","x","y")    

Answer 3

在你的-6行代码的末尾有一个括号。