How can I convert Ordnance Survey six-digit codes to the latlng bounding box of the related 1km grid square?
For example, NH0325: according to Wikipedia this means a 1km square whose south-west corner is 3 km east and 25 km north from the south-west corner of square NH.
Could anyone point me at some code for converting this code to its 1km grid square, ideally in Python?
I already have Paul Agapow's OSGB library - I think this returns the south-west corner of the grid square, in OSGB36 coordinates. I could potentially use this to find the north-east corner, but I don't know how.
I'm displaying the results on an WGS84 map, so it would be better to have the results in WGS84, if possible.
This is all far beyond my knowledge of map projections. Any suggestions very much appreciated.