MacOS – way to limit OS X when searching for apps

While there are obviously differences in the different versions of Python, there are also differences between the "system" Python and those you install via Python.org, MacPorts, Homebrew, etc. All of these "additional" versions can coexist quite happily with the system versions in /System/Library/Frameworks/Python.framework/Versions - I have 2.3, 2.5.6, 2.6.7, and 2.7.2 on my 10.8.4 iMac which originally came with Lion installed. /usr/bin/python is 2.7.2.

Basically, there is no good reason to get rid of any of the system Pythons (they only take up ~200MB), and some very good reasons to not get rid of them. They are included for a reason, and there are various system utilities and programs that depend on them. You could get strange, unexplained behavior if you remove them, and vital stuff may not work, as Python scripts and libraries are behind some major system tools. Python has been designed to have multiple versions living happily side-by-side, so if your system is set up properly (which I generally trust the Apple engineers to have done), there won't be any conflicts as hypothesized by another answer.

If you want to change which version of Python runs by default when you type python into the Terminal prompt, then change your $PATH environment variable to point toward your installation of choice, do not unlink or change /usr/bin/python. For example, I use MacPorts, so /opt/local/bin is ahead of /usr/bin in my $PATH, so I never run the "system" version 2.7.2. You can then start your scripts with

#!/usr/bin/env python

and it will search your path for the correct binary.

You should have no problems at all using MacPorts point to your version of choice. One thing I would suggest, though, is to keep /opt/local/bin/python pointing to the latest version of Python 2 (2.7.5, currently), and use /opt/local/bin/python3 point to 3.3.2. Yes, you have to remember to add the 3 on the end of the command, but several months back I tried setting python to Py3, and occasionally would get weird errors from some programs expecting Py2 to be there.

Hopefully this helps answer your actual question, please let me know if you need anything else.

I have installed Windows 8.1 Pro via Boot Camp on my MacBook Pro Retina 15-inch mid-2015, with OS X Yosemite 10.10.4 and Boot Camp Assistant version 5.1.4. I can prove that this version of Boot Camp is no longer creating hybrid GPT/MBR partition scheme to install Windows 8 x64 on Intel-based Macs, and Windows is directly booted in EFI mode. Here are what I have tried:

1. Running Ubuntu on its installation flash drive, I ran sudo disk -l /dev/sda to check my local Mac SSD; results: MBR: protective, BSD: not present, APM: not present, GPT: present Found valid GPT with protective MBR; using GPT Therefore Windows is not booting from and running on a disk with hybrid GPT/MBR scheme.
2. In Windows, C:\Windows\panther\setupact.log has one entry: Callback_BootEnvironmentDetect: Detected boot environment: EFI How to tell if windows 7 installer boot in EFI or BIOS?

Therefore theoretically Boot Camp is not needed to install Windows 7/8 x64, which support booting from GPT disks on UEFI(that is EFI 2.x)-based systems. But still it's better to use Boot Camp to create the Windows Installation flash drive and download drivers for Windows. The guide: How to install Windows 8.1 on Mac without Boot Camp To sum it up:

1. Partition your disk as you wish in Disk Utility in OS X; just format your desired Windows OS and data partitions as FAT32.
2. Since Retina MacBook Pros do not come with a SuperDrive, you need to create a Windows Installation flash drive from the ISO file. Please do this in Boot Camp Assistant. I have tried run dd command on Mac's Terminal to copy the ISO, but the created flash drive is not bootable on UEFI Macs: the Apple boot manager simply does not recognize the flash disk.
3. Plug in the flash drive, restart the computer and hold option to open Apple boot manager. You will see a yellow drive called "EFI Boot", which is the Windows Installation. Continue the installation as normal, and format your Windows OS partition as NTFS when asked.
4. Whenever the computer restarts, you need to hold option key and select "Windows" drive on your local SSD to continue installation. Finally go into the system and drivers from Boot Camp will automatically install.

You should keep a Time Machine backup before these operations. Even if things really mess up, you can just create a OS X Yosemite installation flash drive, re-format the SSD to one partition and re-install OS X. How to make a bootable OS X 10.10 Yosemite install driveThe newest version of Recovery HD partition will automatically come back. This worked successfully when I wrongly operated the disk in Ubuntu.

Hope this works!