Loading same layers every time

Question

I recently started using Qgis python console for Qgis development. My first task is to load the layer and print its attributes.I firstly load a point layer using code

mylr = QgsVectorLayer("/home/ali/Python Work/work for centerline/","pnt.shp", "ogr")
iter = mylr.getFeatures()
for feature in iter:

geom = feature.geometry()
print "Feature ID %d: " % feature.id()

if geom.type() == QGis.Point:
    x = geom.asPoint()
    print "Point: " + str(x)
elif geom.type() == QGis.Line:
    x = geom.asPolyline()
    print "Line: %d points" % len(x)
elif geom.type() == QGis.Polygon:
    x = geom.asPolygon()
    numPts = 0
    for ring in x:
    numPts += len(ring)
    print "Polygon: %d rings with %d points" % (len(x), numPts)
else:
    print "Unknown"    

attrs = feature.attributes()
print attrs

it printed the attributes of the layer pnt.shp.Then i changed the layer name

mylr = QgsVectorLayer("/home/ali/Python Work/work for centerline/","pgon.shp", "ogr")

all the following code was same.When i run the script it printed the attributes of the layer i loaded before pnt.shp. Every time i run my script it always print the attributes of pnt.shp and do not load the current layer Even if i change the veriables it always print the same layer attributes Please help me to solve this problem

Answer 1

As shown in: http://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/loadlayer.html#vector-layers

The second parameter of QqgVectorLayer() is the name of the layer to be shown in qgis. This should work:

QgsVectorLayer("/home/ali/Python Work/work for centerline/pnt.shp","pnt", "ogr")

QgsVectorLayer("/home/ali/Python Work/work for centerline/pgon.shp","pgon", "ogr")