In Arcgis IProximityOperator.QueryNearestPoint Method was available to get the nearest point. Similarly Is there any function available in pyQgis?
Thanks in Advance.
There is no ready-made solution, you need to program but it is a simple problem of analytical geometry (Nearest neighbor) and the solution was given by Paul Bourke in 1998 (Points, lines, and planes).
Several versions of his algorithm have been proposed in various languages including Python:
The script with shapely can be easily converted to PyQGIS
2) one solution with PyQGIS adapting the script of scw to PyQGIS;
You can use Spatialite  and its
You can try it in QGIS DB Manager connected to any Spatialite database:
Or use it in QGIS Python console: