How to write an equivalent to MapBasic's CreateLine in pyQGIS?.md

From How to write an equivalent to MapBasic's CreateLine in pyQGIS

You can even use the original coordinates of the point shapefile

 

     # iterator, iterate over pairs of points in a list, a layer
    `def pair_points(iterable):
         iterator = iter(iterable)
         prev = None
         item = iterator.next() 
         for next in iterator:
             yield (item,next)
             prev = item
             item = next

      `# using the iterator 
      `for pt1,pt2 in pair_points(layer.getFeatures()):
           ptA = pt1.geometry().asPoint()
           ptB = pt2.geometry().asPoint()
           print ptA, ptB, 
           .....
           line = QgsGeometry.fromPolyline([QgsPoint(ptA), QgsPoint(ptB)])
           print line.asPolyline()
           .....

Example with one of my points layers

    (271927,155249) (272361,153856) line: [(271927,155249), (272361,153856)]
    (272361,153856) (272689,152802) line: [(272361,153856), (272689,152802)]
    ....