Yosemite install OpenCV3

先声明一下，我参考的安装文章在 [这里] 。(http://www.pyimagesearch.com/2016/12/05/macos-install-opencv-3-and-python-3-5/)
我的环境与教程的环境有一些差别，在这之前我安装了Anaconda和Pycharm，所以在安装的时候曾担心会遇到一些冲突的问题，后来想了一下，先不管他了，试试再说。现在我记录一下安装的过程，是边安装边记录的，我也不知道能不能安装成功。

由于之前系统已经安装过homebrew了，所以就跳过安装的步骤，Step #2: Install Homebrew，执行了一下

brew update

 ~/ brew update
Updated 2 taps (homebrew/core, homebrew/science).
==> New Formulae
akamai                      glpk                        metis                       redis@3.2                   veclibfort
arpack                      goose                       octave                      scalapack
bash-snippets               homebrew/science/clips      openblas                    sccache
bento4                      homebrew/science/flexbar    qhull                       suite-sparse
ghc@8.0                     maven@3.0                   qrupdate                    transfig
==> Updated Formulae
afl-fuzz                           get-flash-videos                   libqalculate                       pyenv-virtualenv
afsctool                           getmail                            librdkafka                         pyinvoke
agda                               ghc                                librsvg                            pyqt
allure                             git-fresh                          libtiff ✔                          qscintilla2
amazon-ecs-cli                     gitlab-ci-multi-runner             libtorrent-rasterbar               rclone
ammonite-repl                      gjs                                linkerd                            reattach-to-user-namespace
angular-cli                        gnatsd                             log4cpp                            recoverjpeg
apache-arrow                       gnome-recipes                      logstash                           redis
app-engine-go-64                   gnu-chess                          lxc                                rethinkdb
arangodb                           gnupg                              macvim                             rocksdb
artifactory                        gnupg@1.4                          makensis                           rom-tools
ascii                              gofabric8                          mame                               rtags
assimp                             google-benchmark                   mariadb                            ruby-build
aws-sdk-cpp                        gradle                             memcached                          rust
bacula-fd                          grakn                              menhir                             sbt
bazel                              groonga                            meson                              scala
binutils                           gsoap                              metabase                           scalaenv
bmake                              gtk+3                              metricbeat                         scalariform
btfs                               harfbuzz                           miller                             scw
cabal-install                      haskell-stack                      mingw-w64                          s-libev
caddy                              haste-client                       mkvtoolnix                         sip
cargo-completion                   hdf5 ✔                             mobile-shell                       sjk
catimg                             heroku                             monax                              skinny
chakra                             highlight                          mpc                                snakemake
checkstyle                         homebrew/science/alembic           mpd                                snap-telemetry
chromedriver                       homebrew/science/ampl-mp           mpdas                              softhsm
closure-stylesheets                homebrew/science/bedops            mpg123                             sslyze
cmake                              homebrew/science/ceres-solver      mpv                                stella
cockroach                          homebrew/science/cgns              mspdebug                           supervisor
codec2                             homebrew/science/cmor              mypy                               suricata
conan                              homebrew/science/dynare            mysql                              swiftplate
consul                             homebrew/science/gmsh              mysql-cluster                      syncthing
convmv                             homebrew/science/htslib            mysql-connector-c                  sysdig
convox                             homebrew/science/ipopt             mysql-sandbox                      t1utils
corectl                            homebrew/science/libbigwig         mysql@5.5                          talloc
cromwell                           homebrew/science/littler           mysql@5.6                          tarsnap-gui
crowdin                            homebrew/science/mumps             nano                               tcl-tk
cryptol                            homebrew/science/nextflow          ncmpc                              tcpdump
cython                             homebrew/science/ome-common        ncmpcpp                            tee-clc
dbt                                homebrew/science/ome-files         netpbm                             telegraf
dbus                               homebrew/science/ome-xml           nnn                                teleport
dcos-cli                           homebrew/science/root6             node                               terragrunt
dependency-check                   homebrew/science/vcftools          node-build                         tfenv
dhall-json                         htmldoc                            node@4                             tika
diff-so-fancy                      httpflow                           node@6                             tippecanoe
diffoscope                         hydra                              nomad                              trafficserver
digdag                             hyperscan                          notmuch                            twoping
dmd                                imagemagick                        nsd                                typescript
docker-compose                     imagemagick@6                      nspr                               unrar
docker-compose-completion          influxdb                           nuxeo                              urh
dub                                influxdb@0.8                       ola                                v8@3.15
duck                               ircii                              openrtsp                           vim
elasticsearch                      jags                               opensc                             vimpc
elasticsearch@2.4                  jboss-forge                        openvdb                            vips
elixir                             jenkins                            orc                                voldemort
emscripten                         jenkins-lts                        orientdb                           vowpal-wabbit
encfs                              jfrog-cli-go                       osc                                webdis
etcd                               jhipster                           osm2pgsql                          webpack
etsh                               jmxtrans                           osquery                            whois
evince                             kibana                             osrm-backend                       wine
exploitdb                          kobalt                             oysttyer                           wiredtiger
fabio                              kompose                            packetbeat                         wireguard-tools
fibjs                              kops                               paket                              wireshark
filebeat                           kubernetes-cli                     parallel                           woboq_codebrowser
flake8                             kubernetes-helm                    passenger                          wpscan
flow                               languagetool                       pgbadger                           xapian
fluent-bit                         launch4j                           pgcli                              xsv
folly                              lean-cli                           pioneer                            yarn
format-udf                         libfreenect                        ponyc                              yle-dl
fstar                              libgcrypt                          pre-commit                         you-get
fzf                                libhttpseverywhere                 presto                             youtube-dl
gdk-pixbuf                         libmpdclient                       protobuf-swift                     zabbix
gearman                            libphonenumber                     psqlodbc                           zsh-completions
geos                               libpst                             pulseaudio
 ~/ vi ~/.bash_profile

教程接下来是添加brew的安装路径，以便的命令行输入brew后系统能够找到它，同样，我之前已经安装过了，所以就查看了一下安装路径。已经添加好了。

 ~/ which brew
/usr/local/bin/brew
 ~/ echo $PATH
/Users/zz/anaconda/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
 ~/

接下来教程是安装Python3，这个我之前也安装好了，是装Anaconda的时候装的，并且系统上有好几个Python，在/usr/bin目录下的是osx系统自带的，且为python2.x的版本，我的目标是装python3.x和opencv，所以那个肯定就不能用了。

 ~/ which python3
/Users/zz/anaconda/bin/python3
 ~/
 ~/ which python
/Users/zz/anaconda/bin/python
 ~/

 ~/ ls /usr/bin/pyth*
/usr/bin/python           /usr/bin/python2.6        /usr/bin/python2.7        /usr/bin/pythonw          /usr/bin/pythonw2.7
/usr/bin/python-config    /usr/bin/python2.6-config /usr/bin/python2.7-config /usr/bin/pythonw2.6
 ~/

在这一步，教程使用了brew 安装了python3，装在了/usr/local/bin/python3里面了。而具体我的本机的情况，python3的安装路径则为：

 ~/ which python3
/Users/zz/anaconda/bin/python3
 ~/

所以在后面配置的时候需要把教程中有关/usr/local/bin/python3的路径改成我的 /user/zz/anaconda/bin/python3 ，这是目前能够想到的。

继续。Step #4: Install Python virtual environments and NumPy 接下来是安装 virtual environments.

 pip install virtualenv virtualenvwrapper

这个东西我的系统里确实没有，所以该实际的安装了。

 ~/ pip install virtualenv virtualenvwrapper
Collecting virtualenv
  Downloading virtualenv-15.1.0-py2.py3-none-any.whl (1.8MB)
    100% |████████████████████████████████| 1.8MB 132kB/s
Collecting virtualenvwrapper
  Downloading virtualenvwrapper-4.7.2.tar.gz (90kB)
    100% |████████████████████████████████| 92kB 73kB/s
Collecting virtualenv-clone (from virtualenvwrapper)
  Downloading virtualenv-clone-0.2.6.tar.gz
Collecting stevedore (from virtualenvwrapper)
  Downloading stevedore-1.25.0-py2.py3-none-any.whl
Collecting pbr!=2.1.0,>=2.0.0 (from stevedore->virtualenvwrapper)
  Downloading pbr-3.1.1-py2.py3-none-any.whl (99kB)
    100% |████████████████████████████████| 102kB 55kB/s
Requirement already satisfied: six>=1.9.0 in ./anaconda/lib/python3.6/site-packages (from stevedore->virtualenvwrapper)
Building wheels for collected packages: virtualenvwrapper, virtualenv-clone
  Running setup.py bdist_wheel for virtualenvwrapper ... done
  Stored in directory: /Users/zz/Library/Caches/pip/wheels/3e/7e/eb/31f2187dde819aa4f67ade0ac8401da47257f44c213f153ca2
  Running setup.py bdist_wheel for virtualenv-clone ... done
  Stored in directory: /Users/zz/Library/Caches/pip/wheels/24/51/ef/93120d304d240b4b6c2066454250a1626e04f73d34417b956d
Successfully built virtualenvwrapper virtualenv-clone
Installing collected packages: virtualenv, virtualenv-clone, pbr, stevedore, virtualenvwrapper
Successfully installed pbr-3.1.1 stevedore-1.25.0 virtualenv-15.1.0 virtualenv-clone-0.2.6 virtualenvwrapper-4.7.2
 ~/ ls /usr/local/bin/
2to3                  exrmakepreview        h5format_convert      mdb_copy              ppm2tiff              tiff2pdf
2to3-3.6              exrmaketiled          h5import              mdb_dump              pprof                 tiff2ps
VBoxAutostart         exrmultipart          h5jam                 mdb_load              pydoc3                tiff2rgba
VBoxBalloonCtrl       exrmultiview          h5ls                  mdb_stat              pydoc3.6              tiffcmp
VBoxBugReport         exrstdattr            h5mkgrp               ocs                   python3               tiffcp
VBoxDTrace            f2py                  h5perf_serial         opencv_annotation     python3-32            tiffcrop
VBoxHeadless          fax2ps                h5redeploy            opencv_createsamples  python3-config        tiffdither
VBoxManage            fax2tiff              h5repack              opencv_haartraining   python3.6             tiffdump
VBoxVRDP              gflags_completions.sh h5repart              opencv_performance    python3.6-32          tiffinfo
VirtualBox            gif2h5                h5stat                opencv_traincascade   python3.6-config      tiffmedian
brew                  h52gif                h5unjam               opencv_version        python3.6m            tiffset
cjpeg                 h5c++                 h5watch               opencv_visualisation  python3.6m-config     tiffsplit
cscope                h5cc                  idle3                 pal2rgb               pyvenv                vbox-img
ctags                 h5clear               idle3.6               pip3                  pyvenv-3.6            vboxwebsrv
djpeg                 h5copy                jpegtran              pip3.6                raw2tiff              wrjpgcom
easy_install-3.6      h5debug               leveldbutil           png-fix-itxt          rdjpgcom
exrenvmap             h5diff                libpng-config         pngfix                sandbox-pod
exrheader             h5dump                libpng16-config       pod                   tiff2bw
 ~/ virtualenv_prompt_info

还算顺利，直接就安装完了。
然后接下来，教程说

# Virtualenv/VirtualenvWrapper
source /usr/local/bin/virtualenvwrapper.sh

但是我看了一下，在我本地/usr/local/bin目录下根本就没有virtualenvwrapper.sh这个文件。慌了2秒钟，企图使用直接拼写看看系统能不能自动补全，结果只出来一个virtualenv_prompt_ifo，没有想要的virtualenvwrapper.sh，用find查找出来一堆Permission denied。又进了几个目录看了一下，也还是没有。

 ~/ virtualenv_prompt_info
 ~/ find / -name virtualenvwrapper.sh
find: /.DocumentRevisions-V100: Permission denied
find: /.fseventsd: Permission denied
find: /.Spotlight-V100: Permission denied
find: /.Trashes: Permission denied
find: /dev/fd/3: Not a directory
find: /dev/fd/4: Not a directory
find: /Library/Application Support/Apple/ParentalControls/Users: Permission denied
find: /Library/Application Support/ApplePushService: Permission denied
find: /Library/Application Support/com.apple.TCC: Permission denied
find: /Library/Caches/com.apple.iconservices.store: Permission denied
find: /Library/Caches/com.apple.Spotlight/schema.501.plist: Permission denied
find: /Library/Caches/com.apple.Spotlight/schema.89.plist: Permission denied
find: /Library/Caches/com.apple.Spotlight: Permission denied
find: /private/etc/cups/certs: Permission denied
find: /private/var/agentx: Permission denied
find: /private/var/at/tabs: Permission denied
find: /private/var/at/tmp: Permission denied
find: /private/var/audit: Permission denied
find: /private/var/backups: Permission denied
find: /private/var/db/caches/opendirectory: Permission denied
find: /private/var/db/ConfigurationProfiles/Setup: Permission denied
find: /private/var/db/ConfigurationProfiles/Store: Permission denied
find: /private/var/db/dhcpclient: Permission denied
find: /private/var/db/dslocal/nodes/Default: Permission denied
find: /private/var/db/geod: Permission denied
find: /private/var/db/locationd: Permission denied
find: /private/var/db/lockdown: Permission denied
find: /private/var/db/nsurlsessiond: Permission denied
find: /private/var/db/securityagent: Permission denied
find: /private/var/db/Spotlight: Permission denied
find: /private/var/db/sudo: Permission denied
find: /private/var/db/TokenCache: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/0/com.apple.revisiond.temp: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/0/com.apple.Spotlight: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n000003000000r/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n000003800000t/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n000006w00001q/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n000006w00001q/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000084000021/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000084000021/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000b400002s/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000b400002s/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000bh00002w/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000bh00002w/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000c4000031/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000c4000031/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000s0000068/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000s0000068/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000s800006_/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000s800006_/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000sm00006d/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000sm00006d/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000t800006k/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000th00006m/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000th00006m/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000tm00006n/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000vr00006y/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000vr00006y/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000xc00007b/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000xc00007b/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000y000007h/C: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000y000007h/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000y400007j/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000y800007k/T: Permission denied
find: /private/var/folders/zz/zyxvpxvq6csfxvn_n00000yc00007l/T: Permission denied
find: /private/var/jabberd: Permission denied
find: /private/var/lib/postfix: Permission denied
find: /private/var/log/com.apple.revisiond: Permission denied
find: /private/var/log/watchdogd/log: Permission denied
find: /private/var/log/watchdogd: Permission denied
find: /private/var/root: Permission denied
find: /private/var/run/mds: Permission denied
find: /private/var/spool/cups: Permission denied
find: /private/var/spool/fax: Permission denied
find: /private/var/spool/mqueue: Permission denied
find: /private/var/spool/postfix/active: Permission denied
find: /private/var/spool/postfix/bounce: Permission denied
find: /private/var/spool/postfix/corrupt: Permission denied
find: /private/var/spool/postfix/defer: Permission denied
find: /private/var/spool/postfix/deferred: Permission denied
find: /private/var/spool/postfix/flush: Permission denied
find: /private/var/spool/postfix/hold: Permission denied
find: /private/var/spool/postfix/incoming: Permission denied
find: /private/var/spool/postfix/maildrop: Permission denied
find: /private/var/spool/postfix/private: Permission denied
find: /private/var/spool/postfix/public: Permission denied
find: /private/var/spool/postfix/saved: Permission denied
find: /private/var/spool/postfix/trace: Permission denied
find: /System/Library/Caches/com.apple.coresymbolicationd: Permission denied
find: /System/Library/DirectoryServices/DefaultLocalDB/Default: Permission denied
find: /System/Library/User Template: Permission denied
/Users/zz/anaconda/bin/virtualenvwrapper.sh
find: /usr/sbin/authserver: Permission denied
find: /Volumes/PyCharm/.Trashes: Permission denied
 ~/ ls /Library/Frameworks/Python.framework/Versions/3.6/bin/
2to3              idle3             pip3.6            python3           python3.6         python3.6m        pyvenv-3.6
2to3-3.6          idle3.6           pydoc3            python3-32        python3.6-32      python3.6m-config
easy_install-3.6  pip3              pydoc3.6          python3-config    python3.6-config  pyvenv
 ~/ ls /Library/Frameworks/Python.framework/Versions/3.6/bin/ -al
ls: -al: No such file or directory
/Library/Frameworks/Python.framework/Versions/3.6/bin/:
2to3              idle3             pip3.6            python3           python3.6         python3.6m        pyvenv-3.6
2to3-3.6          idle3.6           pydoc3            python3-32        python3.6-32      python3.6m-config
easy_install-3.6  pip3              pydoc3.6          python3-config    python3.6-config  pyvenv
 ~/ ls -al /Library/Frameworks/Python.framework/Versions/3.6/bin/
total 272
drwxrwxr-x  21 root  admin    714 Feb  9 08:09 .
drwxrwxr-x  10 root  admin    340 Feb  9 08:09 ..
lrwxr-xr-x   1 root  admin      8 Feb  9 08:09 2to3 -> 2to3-3.6
-rwxrwxr-x   1 root  admin    140 Dec 23  2016 2to3-3.6
-rwxrwxr-x   1 root  admin    281 Feb  9 08:09 easy_install-3.6
lrwxr-xr-x   1 root  admin      7 Feb  9 08:09 idle3 -> idle3.6
-rwxrwxr-x   1 root  admin    138 Dec 23  2016 idle3.6
-rwxrwxr-x   1 root  admin    253 Feb  9 08:09 pip3
-rwxrwxr-x   1 root  admin    253 Feb  9 08:09 pip3.6
lrwxr-xr-x   1 root  admin      8 Feb  9 08:09 pydoc3 -> pydoc3.6
-rwxrwxr-x   1 root  admin    123 Dec 23  2016 pydoc3.6
lrwxr-xr-x   1 root  admin      9 Feb  9 08:09 python3 -> python3.6
lrwxr-xr-x   1 root  admin     12 Feb  9 08:09 python3-32 -> python3.6-32
lrwxr-xr-x   1 root  admin     16 Feb  9 08:09 python3-config -> python3.6-config
-rwxrwxr-x   2 root  admin  25920 Dec 23  2016 python3.6
-rwxrwxr-x   1 root  admin  13568 Dec 23  2016 python3.6-32
lrwxr-xr-x   1 root  admin     17 Feb  9 08:09 python3.6-config -> python3.6m-config
-rwxrwxr-x   2 root  admin  25920 Dec 23  2016 python3.6m
-rwxrwxr-x   1 root  admin   2081 Dec 23  2016 python3.6m-config
lrwxr-xr-x   1 root  admin     10 Feb  9 08:09 pyvenv -> pyvenv-3.6
-rwxrwxr-x   1 root  admin    480 Dec 23  2016 pyvenv-3.6
 ~/ ls /usr/local/bin

2to3                  exrmakepreview        h5format_convert      mdb_copy              ppm2tiff              tiff2pdf
2to3-3.6              exrmaketiled          h5import              mdb_dump              pprof                 tiff2ps
VBoxAutostart         exrmultipart          h5jam                 mdb_load              pydoc3                tiff2rgba
VBoxBalloonCtrl       exrmultiview          h5ls                  mdb_stat              pydoc3.6              tiffcmp
VBoxBugReport         exrstdattr            h5mkgrp               ocs                   python3               tiffcp
VBoxDTrace            f2py                  h5perf_serial         opencv_annotation     python3-32            tiffcrop
VBoxHeadless          fax2ps                h5redeploy            opencv_createsamples  python3-config        tiffdither
VBoxManage            fax2tiff              h5repack              opencv_haartraining   python3.6             tiffdump
VBoxVRDP              gflags_completions.sh h5repart              opencv_performance    python3.6-32          tiffinfo
VirtualBox            gif2h5                h5stat                opencv_traincascade   python3.6-config      tiffmedian
brew                  h52gif                h5unjam               opencv_version        python3.6m            tiffset
cjpeg                 h5c++                 h5watch               opencv_visualisation  python3.6m-config     tiffsplit
cscope                h5cc                  idle3                 pal2rgb               pyvenv                vbox-img
ctags                 h5clear               idle3.6               pip3                  pyvenv-3.6            vboxwebsrv
djpeg                 h5copy                jpegtran              pip3.6                raw2tiff              wrjpgcom
easy_install-3.6      h5debug               leveldbutil           png-fix-itxt          rdjpgcom
exrenvmap             h5diff                libpng-config         pngfix                sandbox-pod
exrheader             h5dump                libpng16-config       pod                   tiff2bw

这时想起来，还有个which，赶紧试试。终于找到了，原来它就在/user/zz/anaconda/bin/里面，看来都安装到anaconda的目录了。按照教程也把它的路径添加到~/.bash_profile，以便在以后打开终端的时候自动加载它。同时，先用source更新一下本终端。

 ~/ which virtualenvwrapper.sh
/Users/zz/anaconda/bin/virtualenvwrapper.sh
 ~/ vi ~/.bash_profile
 ~/ source ~/.bash_profile
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/premkproject
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/postmkproject
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/initialize
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/premkvirtualenv
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/postmkvirtualenv
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/prermvirtualenv
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/postrmvirtualenv
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/predeactivate
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/postdeactivate
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/preactivate
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/postactivate
virtualenvwrapper.user_scripts creating /Users/zz/.virtualenvs/get_env_details
 ~/ ls .virtualenvs
get_env_details  postactivate     postmkproject    postrmvirtualenv predeactivate    premkvirtualenv
initialize       postdeactivate   postmkvirtualenv preactivate      premkproject     prermvirtualenv
 ~/ ls -al .virtualenvs
total 96
drwxr-xr-x  14 zz  staff   476 Jul 29 16:53 .
drwxr-xr-x+ 47 zz  staff  1598 Jul 29 16:53 ..
-rwxr-xr-x   1 zz  staff   134 Jul 29 16:53 get_env_details
-rw-r--r--   1 zz  staff    95 Jul 29 16:53 initialize
-rw-r--r--   1 zz  staff    72 Jul 29 16:53 postactivate
-rw-r--r--   1 zz  staff    74 Jul 29 16:53 postdeactivate
-rwxr-xr-x   1 zz  staff    65 Jul 29 16:53 postmkproject
-rw-r--r--   1 zz  staff    72 Jul 29 16:53 postmkvirtualenv
-rwxr-xr-x   1 zz  staff   109 Jul 29 16:53 postrmvirtualenv
-rwxr-xr-x   1 zz  staff    98 Jul 29 16:53 preactivate
-rw-r--r--   1 zz  staff    75 Jul 29 16:53 predeactivate
-rwxr-xr-x   1 zz  staff    90 Jul 29 16:53 premkproject
-rwxr-xr-x   1 zz  staff   129 Jul 29 16:53 premkvirtualenv
-rwxr-xr-x   1 zz  staff   110 Jul 29 16:53 prermvirtualenv
 ~/

接着跟着教程走。
Create your Python 3 virtual environment

$ mkvirtualenv cv -p python3

我本地执行结果：

 ~/ $ mkvirtualenv cv -p python3
zsh: command not found: $
 ~/ mkvirtualenv cv -p python3
zsh: command not found: mkvirtualenv
 ~/ brew install mkvirtualenv
Updating Homebrew...
Error: No available formula with the name "mkvirtualenv"
==> Searching for a previously deleted formula...
Warning: homebrew/core is shallow clone. To get complete history run:
  git -C "$(brew --repo homebrew/core)" fetch --unshallow

Error: No previously deleted formula found.
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
Error: No formulae found in taps.

很明显，又一次装B失败。系统没有找到mkvirtualenv，由于想都没想就用brew 尝试安装它，直到提示安装失败才回过味来，是不是它是在刚才安装 virtualenv virtualenvwrapper 时装上的东西，但是为什么提示找不到呢，赶紧又source ~/.bash_profile，终于可以执行了。回想了一下为什么要source一下才行，不是应该系统自动初始化的吗？难道是我这几天没有关机，导致没有初始化console的关系？先不管了。本以为会大功告成，结果出来了错误。

 ~/ source ~/.bash_profile
 ~/ mkvirtualenv cv -p python3
Running virtualenv with interpreter /Users/zz/anaconda/bin/python3
Using base prefix '/Users/zz/anaconda'
New python executable in /Users/zz/.virtualenvs/cv/bin/python3
Also creating executable in /Users/zz/.virtualenvs/cv/bin/python
dyld: Library not loaded: @rpath/libpython3.6m.dylib
  Referenced from: /Users/zz/.virtualenvs/cv/bin/python3
  Reason: image not found
ERROR: The executable /Users/zz/.virtualenvs/cv/bin/python3 is not functioning
ERROR: It thinks sys.prefix is '/Users/zz/.virtualenvs' (should be '/Users/zz/.virtualenvs/cv')
ERROR: virtualenv is not compatible with this system or executable
 ~/

说实话，直到此时，我才查了一下：

virtualenv 是一个可以在同一计算机中隔离多个python版本的工具。有时，两个不同的项目可能需要不同版本的python，如 python2.6.6 / python3.0 ，但是如果都装到一起，经常会导致问题。所以需要一个工具能够将这两种或几种不同版本的环境隔离开来，需要哪个版本就切换到哪个版本做为默认版本。virtualenv 既是满足这个需求的工具。它能够用于创建独立的Python环境，多个Python相互独立，互不影响，能够：

在没有权限的情况下安装新套件
不同应用可以使用不同的套件版本
套件升级不影响其他应用

作者：乾九二
链接：http://www.jianshu.com/p/44ab75fbaef2
來源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。