我按照这里的说明分三步做到了这一点:这都是从这里直接获取的:http://ipython.readthedocs.io/en/stable/install/kernel_install.html。我目前正在运行Python 2。已安装Anaconda 4.2.13。

1)首先安装最新版本的python:

conda create -n python3 python=3 ipykernel

2)下一步激活python3

activate python3

3)安装内核:

python -m ipykernel install --user

如果你已经安装了python3，想要安装python2，请切换上面的python2和python3。当你打开一个新的笔记本时，你现在可以在python2或python3之间进行选择。

在另一个上面安装最常用的一个(我的例子是3.3)。这将迫使IDLE使用您想要的那个。

或者(来自python3.3 README):

安装多个版本

On Unix and Mac systems if you intend to install multiple versions of Python using the same installation prefix (--prefix argument to the configure script) you must take care that your primary python executable is not overwritten by the installation of a different version. All files and directories installed using "make altinstall" contain the major and minor version and can thus live side-by-side. "make install" also creates ${prefix}/bin/python3 which refers to ${prefix}/bin/pythonX.Y. If you intend to install multiple versions using the same prefix you must decide which version (if any) is your "primary" version. Install that version using "make install". Install all other versions using "make altinstall".

例如，如果你想安装Python 2.6, 2.7和3.3，其中2.7是 主版本，您将在2.7构建目录中执行“make install” 而其他的则是“make altinstall”。

我在windows中有多个版本。 我只是改变了我不是默认版本的exe名称。

Python.exe——> python26.exe python .exe——> pythonw26.exe

至于软件包安装程序，大多数exe安装程序也允许您选择python安装程序来添加软件包。 对于手动安装，检查——prefix选项来定义包应该安装在哪里:

http://docs.python.org/install/index.html#alternate-installation-windows-the-prefix-scheme

只有在Python IDE中运行代码才有效

我的windows操作系统上同时安装了Python 2.7和Python 3.3。如果我试图启动一个文件，它通常会在python 2.7 IDE上打开。我如何解决这个问题，是当我选择在python 3.3上运行我的代码时，我打开python 3.3 IDLE(python GUI)，选择文件，用IDLE打开我的文件并保存它。然后，当我运行我的代码时，它运行到我当前打开它的IDLE。反之亦然。

Windows版本有Python启动器，请参阅3.4节。Windows Python启动器

I just had to install them. Then I used the free (and portable) soft at http://defaultprogramseditor.com/ under "File type settings"/"Context menu"/search:"py", chose .py file and added an 'open' command for the 2 IDLE by copying the existant command named 'open with IDLE, changing names to IDLE 3.4.1/2.7.8, and remplacing the files numbers of their respective versions in the program path. Now I have just to right click the .py file and chose which IDLE I want to use. Can do the same with direct interpreters if you prefer.