for singleShapefile in inputShapefiles:
    arcpy.SpatialJoin_analysis(studyarea, singleShapefile, arcpy.Polygon, 'JOIN_ONE_TO_ONE', 'KEEP_ALL', '', 'INTERSECT')

for singleShapefile in inputShapefiles:
    arcpy.SpatialJoin_analysis(studyarea, singleShapefile, 'in_memory/test', 'JOIN_ONE_TO_ONE', 'KEEP_ALL', '', 'INTERSECT')