import arcpy

workspaces = arcpy.ListWorkspaces("//nyx-galli/eGIS/Data/Raster/Imagery/Aerial/SGIC/2008_Mapcon/Block4*", "Folder")
datasets = arcpy.ListDatasets("D:/TestRasterMosaic/BW.gdb/Block_4*", "Mosaic")

for i in workspaces:
    workspaces2 = arcpy.ListWorkspaces("", "Folder")