Changing CRS transformation using QGIS python code?

Question

I am generating some maps with the python standalone scripting in QGIS. When i load Polygon shapefile with the CH1903 / LV03 CRS ( EPSG-21781) and fetching SQL database table having WGS1984 CRS (EPSG-4326) sequence of Layers are as follows

1. Polygon Shapefile ( CH1903 / LV03 CRS -EPSG-21781)
2. SQL Database table (WGS1984 CRS -EPSG-4326)
3. Output Map units is in CH1903 / LV03 CRS -EPSG-21781 for Manually added layers
4. Output Map units is in WGS1984 CRS -EPSG-4326) for standalone script with same shapefile and same data.

Now my question is how to change CRS transformation in standalone script where i will get correct output in the form of CH1904 CRS after loading shapefile and point layer data from SQL database.

Answer 1

You may change the CRS of a layer using qgis reprojection algorithm qgis:reprojectlayer algorithm like this:

reproject=processing.runalg('qgis:reprojectlayer',layer,'EPSG:32630',None)

You're not obligated to save the output layer