Python3系と2系の切り替え方

Question

###前提・実現したいこと
Python3系と2系の切り替え方がわからず、３系に変更できません。
以下の参考記事1を見ながら進めています。
参考記事１

###発生している問題・エラーメッセージ
HomeBrewのインストールでもエラーが起こっているので、これも原因かもしれません

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/share/doc/homebrew
/usr/local/share/man/man1/brew.1
/usr/local/share/zsh/site-functions/_brew
/usr/local/etc/bash_completion.d/brew
/usr/local/Homebrew
==> The following new directories will be created:
/usr/local/Frameworks
/usr/local/sbin

Press RETURN to continue or any other key to abort
==> /usr/bin/sudo /bin/mkdir -p /usr/local/Frameworks /usr/local/sbin
Password:
==> /usr/bin/sudo /bin/chmod g+rwx /usr/local/Frameworks /usr/local/sbin
==> /usr/bin/sudo /bin/chmod 755 /usr/local/share/zsh /usr/local/share/zsh/site-functions
==> /usr/bin/sudo /usr/sbin/chown yamatonao /usr/local/Frameworks /usr/local/sbin
==> /usr/bin/sudo /usr/bin/chgrp admin /usr/local/Frameworks /usr/local/sbin
==> /usr/bin/sudo /bin/mkdir -p /Library/Caches/Homebrew
==> /usr/bin/sudo /bin/chmod g+rwx /Library/Caches/Homebrew
==> /usr/bin/sudo /usr/sbin/chown yamatonao /Library/Caches/Homebrew
==> Downloading and installing Homebrew...
remote: Counting objects: 45, done.
remote: Compressing objects: 100% (15/15), done.
remote: Total 45 (delta 36), reused 39 (delta 30), pack-reused 0
Unpacking objects: 100% (45/45), done.
From https://github.com/Homebrew/brew
   1ff628e2..7f1d5903  master     -> origin/master
HEAD is now at 7f1d5903 Merge pull request #3465 from sjackman/vcs-requirement
Updated 1 tap (homebrew/core).
==> Cleaning up /Library/Caches/Homebrew...
==> Migrating /Library/Caches/Homebrew to /Users/yamatonao/Library/Caches/Homebrew...
==> Deleting /Library/Caches/Homebrew...
==> New Formulae
clingo                            mrboom                            raylib
==> Updated Formulae
aspcud              geth                midnight-commander  shfmt               urh
azure-cli@1         huexpress           mpd                 sile                youtube-dl
blink1              jhipster            nghttp2             sslyze
checkstyle          ldc                 sbt                 termius
exim                librealsense        sceptre             tgui
fail2ban            little-cms2         sdl2_mixer          tidy-html5
==> Deleted Formulae
clasp                                               gringo
Error: Could not link:
/usr/local/etc/bash_completion.d/brew

Please delete these paths and run `brew update`.
Error: Could not link:
/usr/local/share/zsh/site-functions/_brew

Please delete these paths and run `brew update`.
Error: Could not link:
/usr/local/share/man/man1/brew.1

Please delete these paths and run `brew update`.
Error: Could not link:
/usr/local/share/doc/homebrew

Please delete these paths and run `brew update`.
==> Installation successful!

==> Homebrew has enabled anonymous aggregate user behaviour analytics.
Read the analytics documentation (and how to opt-out) here:
  https://docs.brew.sh/Analytics.html

==> Next steps:
- Run `brew help` to get started
- Further documentation: 
    https://docs.brew.sh

3.5.0をpyenvでインストールしようとした時に発生する問題

$pyenv install 3.5.0
Downloading Python-3.5.0.tar.xz...
-> https://www.python.org/ftp/python/3.5.0/Python-3.5.0.tar.xz
Installing Python-3.5.0...
ERROR: The Python ssl extension was not compiled. Missing the OpenSSL lib?

Please consult to the Wiki page to fix the problem.
https://github.com/pyenv/pyenv/wiki/Common-build-problems


BUILD FAILED (OS X 10.13.1 using python-build 20160602)

Inspect or clean up the working tree at /var/folders/v9/08xd0ck5243g91k5xz5cy0br0000gn/T/python-build.20171127102654.36065
Results logged to /var/folders/v9/08xd0ck5243g91k5xz5cy0br0000gn/T/python-build.20171127102654.36065.log

Last 10 log lines:
(cd /Users/yamatonao/.pyenv/versions/3.5.0/share/man/man1; ln -s python3.5.1 python3.1)
if test "xupgrade" != "xno"  ; then \
		case upgrade in \
			upgrade) ensurepip="--upgrade" ;; \
			install|*) ensurepip="" ;; \
		esac; \
		 ./python.exe -E -m ensurepip \
			$ensurepip --root=/ ; \
	fi
Ignoring ensurepip failure: pip 7.1.2 requires SSL/TLS
yamatonao-no-MacBook-Air:~ yamatonao$ python --version
Python 2.7.14
yamatonao-no-MacBook-Air:~ yamatonao$ easy_install pip
Searching for pip
Best match: pip 9.0.1
Adding pip 9.0.1 to easy-install.pth file
Installing pip script to /Library/Frameworks/Python.framework/Versions/2.7/bin
Installing pip3.5 script to /Library/Frameworks/Python.framework/Versions/2.7/bin
Installing pip3 script to /Library/Frameworks/Python.framework/Versions/2.7/bin

Using /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
Processing dependencies for pip
Finished processing dependencies for pip

###該当のソースコード
現在のPythonのバージョンです

$ python --version
Python 2.7.14

Answer 1

MacでHomebrewが入っているという前提でいいのですよね。

brew install openssl
env CPPFLAGS="-I/usr/local/opt/openssl/include" LDFLAGS="-L/usr/local/opt/openssl/lib" pyenv install 3.5.0

このようにしてみてください。

(追記)

env CPPFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib" pyenv install 3.5.0

だと失敗しますね。必要なファイルは/usr/local/opt/opensslにしかないようです。

brew install opensslすると

For compilers to find this software you may need to set:
    LDFLAGS:  -L/usr/local/opt/openssl/lib
    CPPFLAGS: -I/usr/local/opt/openssl/include

といわれるので素直に従えばいいということですね。

Comments

[退会済みユーザー]

ご回答いただきましてありがとうございました。

Answer 2

opensslパッケージが不足しているためにコンパイルに失敗しているものと思われます。
上記パッケージを導入して再度実行されるといかがでしょうか。
コマンドは下記になるかと思います。

brew install openssl

Comments

[退会済みユーザー]

ご回答いただきましてありがとうございました。