Failed to locate python, requesting installation of command line developer tools

Notice: Beginning from the Xcode version 6.1, the Xcode Command Line Tools are automatically installed during Xcode installation.

Check whether the Xcode command line tools are installed on your Mac:

1. Start Xcode on the Mac.
2. Choose Preferences from the Xcode menu.
   
3. In the General window, click the Locations tab.
4. On the Location window, check that the Command Line Tools option shows the Xcode version (with which the Command Line Tools were installed). This means that the Xcode Command Line Tools are already installed and you do not need to install them.
   

If the Xcode Command Line Tools are not installed:

In this case the Command Line Tools option does not show the Xcode version. You can install the Xcode command-line tools in either of two ways:

1. Start Xcode on the Mac.
2. Choose Preferences from the Xcode menu.
3. In the General panel, click Downloads.
4. On the Downloads window, choose the Components tab.
5. Click the Install button next to Command Line Tools.
   
6. You are asked for your Apple Developer login during the install process.

1. On your Mac, to download the Xcode command line tools directly from the developer portal as a .dmg file, go to https://developer.apple.com/downloads/index.action.
2. You are asked for your Apple Developer login during the install process.
3. On the Downloads for Apple Developer list, select the Command Line Tools entry that you want.

See Also

• Working with a Mac and a PC
• Installing Xcode on a Mac
• FireMonkey Platform Prerequisites

The latest version of Mac OS X, High Sierra, comes with Python 2.7 out of the box.

You do not need to install or configure anything else to use Python 2. These instructions document the installation of Python 3.

The version of Python that ships with OS X is great for learning, but it’s not good for development. The version shipped with OS X may be out of date from the official current Python release, which is considered the stable production version.

Doing it Right¶

Let’s install a real version of Python.

Before installing Python, you’ll need to install GCC. GCC can be obtained by downloading XCode, the smaller Command Line Tools (must have an Apple account) or the even smaller OSX-GCC-Installer package.

Note

If you already have XCode installed, do not install OSX-GCC-Installer. In combination, the software can cause issues that are difficult to diagnose.

Note

If you perform a fresh install of XCode, you will also need to add the commandline tools by running xcode-select --install on the terminal.

While OS X comes with a large number of UNIX utilities, those familiar with Linux systems will notice one key component missing: a package manager. Homebrew fills this void.

To install Homebrew, open Terminal or your favorite OSX terminal emulator and run

$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

The script will explain what changes it will make and prompt you before the installation begins. Once you’ve installed Homebrew, insert the Homebrew directory at the top of your PATH environment variable. You can do this by adding the following line at the bottom of your ~/.profile file

export PATH=/usr/local/bin:/usr/local/sbin:$PATH

Now, we can install Python 3:

This will take a minute or two.

Pip¶

Homebrew installs pip pointing to the Homebrew’d Python 3 for you.

Working with Python 3¶

At this point, you have the system Python 2.7 available, potentially the Homebrew version of Python 2 installed, and the Homebrew version of Python 3 as well.

will launch the homebrew-installed Python 3 interpreter.

will launch the homebrew-installed Python 2 interpreter (if any).

will launch the homebrew-installed Python 3 interpreter.

If the Homebrew version of Python 2 is installed then pip2 will point to Python 2. If the Homebrew version of Python 3 is installed then pip will point to Python 3.

The rest of the guide will assume that python references Python 3.

# Do I have a Python 3 installed? $ python --version Python 3.6.4 # Success! # If you still see 2.7 ensure in PATH /usr/local/bin/ takes precedence over /usr/bin/

Pipenv & Virtual Environments¶

The next step is to install Pipenv, so you can install dependencies and manage virtual environments.

A Virtual Environment is a tool to keep the dependencies required by different projects in separate places, by creating virtual Python environments for them. It solves the “Project X depends on version 1.x but, Project Y needs 4.x” dilemma, and keeps your global site-packages directory clean and manageable.

For example, you can work on a project which requires Django 1.10 while also maintaining a project which requires Django 1.8.

So, onward! To the Pipenv & Virtual Environments docs!

This page is a remixed version of another guide, which is available under the same license.

How do I install command line tools?

How do I know if I have command line tools on my Mac?

How do I update my command line tools on Mac?

What is command line developer tools in Mac?