This list of paths worked great.
I have installed Pro single-user as I do not have admin access to this machine so cannot edit the Python34 folder - so I solve the problem using the PYTHONPATH environment variable. I launch python here from its own batfile so I don't confuse my Desktop environment, which has a PYTHONPATH set up to access my Desktop 10x scripts.
py34.bat
:: start python 3.4 with ArcGIS Pro arcpy available
@echo off
set AGPHOME=C:\Users\cprice\AppData\Local\Programs\ArcGIS Pro
set PYTHONPATH=^
%AGPHOME%\bin;^
%AGPHOME%\Resources\ArcPy;^
%AGPHOME%\Resources\ArcToolBox\Scripts;^
%AGPHOME%\bin\Python\Lib\site-packages;^
C:\Python34\Lib\site-packages
C:\Python34\python.exe %1 %2 %3 %4 %5
This seems to work fine:
Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 10:45:13) [MSC v.1600 64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> import arcpy
>>> arcpy.GetInstallInfo()
{'Version': '1.0', 'InstallTime': '8:45:39', 'SPBuild': 'N/A', 'ProductName': 'ArcGISPro', 'BuildNumber': '1472', 'InstallType': 'N/A', 'InstallDate': '10/30/2014', 'SourceDir': 'F:\\EsriMedia\\ArcGISPro_PreRelease\\ArcGISPro\\', 'SPNumber': 'N/A', 'Installer': 'cprice', 'InstallDir': 'c:\\users\\cprice\\appdata\\local\\programs\\arcgis pro\\'}
>>>