problem with dissolving a stream

Hello

can any one help me with a python script to dissolve a stream using their stream order. when i use arcgis tool to dissolve the stream segment using their order,some of the higher order segments join together. example is like 2 segments of order 2 join together to form one segment of order 2.i normally use split tool to split.but i want to write a tool and i need to automate this procedure to continue with my work. thanks in advance