I have ArcGIS 10.2 installed on my machine. When ArcGIS was installed, python 2.7.3(32 bits) was also installed. I need python 2.7.5 64bits for some gdal functions. So I installed python 2.7.5 64bits stand alone. Now there are two python installed with two python shells. One (2.7.3 32bits) can be started from Start---->All Programs--->Python27--->IDLE(GUI). The other(2.7.5 64bits) is from Start---->All Programs--->ArcGIS--->Python27--->IDLE(GUI).
Till now I have my work done in python2.7.5 64bits. Now I want to integrate a model I built in Modelbuilder ArcGIS 10.2. I export this model to python script so that I can see the code behind. I need to import ArcPy module to use ArcPy functions. I tried several ways but no good luck. Is there any way that I can import arcpy module in this python shell (2.7.5 64bits, not the one installed with ArcGIS)? Should I install arcpy package first, like what I did for other module? But I didn't see where to download it. Thank you!
Solved：Thanks to all the folks here! Finally it is resolved. So I followed the link given by @PolyGeo and asked our IT staff to download the package and installed for me. Now my python (came with ArcGIS) is 2.7.5 64bit. I also uninstalled the stand alone python. Re-install all the modules.