Mac builds Python2 PYTHON3 development environment

The latest version of the MacOS Sierra default Python environment is still 2.7.10, this article describes the use of brew installation python3.5 and simple configuration to create a PYTHON2,PYTHON3 coexistence development environment

Try the brew installation directly, prompting you to perform a brew link gdbm

Follow the prompts to execute the brew link gdbm, prompting for directory permissions issues

thatsitdemacbook-pro:~ thatsit$ Brew link gdbmlinking/usr/local/cellar/gdbm/1.12...error:could not symlink share/man/ MAN3/GDBM.3/USR/LOCAL/SHARE/MAN/MAN3 is not writable.thatsitdemacbook-pro:~ thatsit$

Try sudo to perform brew, prompting for root permission is no longer supported

Confirm Directory Permissions and adjust

thatsitdemacbook-pro:~ thatsit$ ll/usr/local/share/man/man3/total 240-rw-rw-r--1 root wheel 25111 1 cdt.3-rw-rw- r--1 root Wheel 27894 1 cgraph.3-rw-rw-r--1 root Wheel 1762 1 expr.3-rw-rw-r--1 root wheel 2103 1 12 20 gvc.3-rw-rw-r--1 root Wheel 2966 1 gvpr.3-rw-rw-r--1 root wheel 9628 1 pack.3-rw-rw-r--1 root wheel 5386 1 pathplan.3-rw-rw-r--1 root wheel 15026 1 tcldot.3tcl-rw-rw-r--1 root wheel 7109 1 Tksplin e.3tk-rw-rw-r--1 root wheel 8157 1 xdot.3thatsitdemacbook-pro:~ thatsit$ thatsitdemacbook-pro:~ thatsit$ sudo cho Wn-r thatsit/usr/local/share/man/man3/thatsitdemacbook-pro:~ thatsit$

Execute again, OK

thatsitdemacbook-pro:~ thatsit$ Brew Link gdbmlinking/usr/local/cellar/gdbm/1.12 ... Symlinks createdthatsitdemacbook-pro:~ thatsit$thatsitdemacbook-pro:~ thatsit$ Brew Install python3==> Installing dependencies for python3:xz==> installing Python3 dependency:xz==> downloading https:// homebrew.bintray.com/bottles/xz-5.2.2.el_capitan.bottle.tar.gz################################################ ######################## 100.0%==> pouring xz-5.2.2.el_capitan.bottle.tar.gzerror:the ' brew link ' step did not Complete Successfullythe formula built, but isn't symlinked into/usr/localcould not symlink lib/pkgconfig/liblzma.pc/usr /local/lib/pkgconfig is not writable. Can you try again using:brew link xz==> Summary?? /usr/local/cellar/xz/5.2.2:91 files, 1.4m==> installing python3==> downloading https://homebrew.bintray.com/ bottles/python3-3.5.2_3.el_capitan.bottle.tar.gz############################################################## ########## 100.0%j==> Pouring PythoN3-3.5.2_3.el_capitan.bottle.tar.gzerror:the ' Brew link ' step did not complete successfullythe formula built; symlinked into/usr/localcould not symlink lib/pkgconfig/python-3.5.pc/usr/local/lib/pkgconfig are not writable. You can try again using:brew link python3==> using the sandbox==>/usr/local/cellar/python3/3.5.2_3/bin/python3-s s etup.py--no-user-cfg Install--force--verbose--install-scripts=/usr/local/cellar/python3/3.5.2_3/bin-- Install-lib=/usr/local/lib/python3.5/site-packages--single-version-externally-managed--record=installed.txt== >/usr/local/cellar/python3/3.5.2_3/bin/python3-s setup.py--no-user-cfg Install--force--verbose-- Install-scripts=/usr/local/cellar/python3/3.5.2_3/bin--install-lib=/usr/local/lib/python3.5/site-packages-- Single-version-externally-managed--record=installed.txt==>/usr/local/cellar/python3/3.5.2_3/bin/python3-s setup.py--no-user-cfg Install--force--verbose--install-scripts=/usr/local/cellar/python3/3.5.2_3/bIn--install-lib=/usr/local/lib/python3.5/site-packages--single-version-externally-managed--record= Installed.txt==> Caveatspip, Setuptools, and wheel have been installed. To update thempip3 install--upgrade pip setuptools wheelyou can install Python packages WITHPIP3 Install <package>t Hey'll install into the site-package directory/usr/local/lib/python3.5/site-packagessee:https://github.com/ Homebrew/brew/blob/master/docs/homebrew-and-python.md.app bundles were installed. Run ' Brew Linkapps python3 ' to symlink these to/applications.==> Summary?? /usr/local/cellar/python3/3.5.2_3:3,498 files, 53.3mthatsitdemacbook-pro:~ thatsit$

Adding PYTHON3 Environment variables

thatsitdemacbook-pro:~ thatsit$ tail-1/etc/profileexport path=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/ local/cellar/python3/3.5.2_3/binthatsitdemacbook-pro:~ thatsit$

Test

Thatsitdemacbook-pro:bin thatsit$ Pythonpython 2.7.10 (default, OCT, 19:19:21) [GCC 4.2.1 Compatible Apple LLVM 7.0 .0 (clang-700.0.59.5)] on Darwintype ' help ', ' copyright ', ' credits ' or ' license ' for more information.>>> ^dthats Itdemacbook-pro:bin thatsit$ Python3python 3.5.2 (default, OCT, 05:05:28) [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (c lang-800.0.38)] on Darwintype ' help ', ' copyright ', ' credits ' or ' license ' for more information.>>> Thatsitdemacbook-pro:bin thatsit$

　　

Done

Mac builds Python2 PYTHON3 development environment