Ubuntu 16.04 安裝 Python 3.6 + OpenCV的虛擬環境

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1. Ubuntu 14.04/16.04安裝Python 3.6

方法一 本身編譯安裝：

# 安裝編譯必需的軟件包
sudo apt install build-essential checkinstall
sudo apt install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev

# 下載並解壓Python 3.6的源代碼
wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tar.xz
tar xvf Python-3.6.0.tar.xz

#編譯安裝
cd Python-3.6.0/
./configure
sudo make altinstall

 

make altinstall 命令會跳過建立symlink的步驟，所以/usr/bin/python仍然指向系統自帶的老版本python，不至於把Ubuntu系統搞崩潰。

方法二 使用PPA源進行安裝

這是一個省事兒的方法，適合懶人用。

sudo add-apt-repository ppa:jonathonf/python-3.6

sudo apt update

sudo apt install python3.6 python3.6-dev

2. 設置Python虛擬環境

Ubuntu系統默認的Python是2.7，爲了使多個Python版本共存，咱們使用virtualenv/virtualenvwrapper來管理不一樣的Python版本和相應的軟件包。
virtualenvwrapper是virtualenv的擴展，使得管理虛擬環境更加方便。

sudo pip install virtualenv virtualenvwrapper

配置 virtualenvwarpper

默認virtualenvwrapper安裝在/usr/local/bin下面，實際上須要運行virtualenvwrapper.sh文件才行；因此須要先進行配置一下：

建立虛擬環境管理目錄: mkdir $HOME/.virtualenvs
在~/.bashrc中添加行：

export VIRTUALENV_USE_DISTRIBUTE=1        #  老是使用 pip/distribute       export WORKON_HOME=$HOME/.virtualenvs   # 全部虛擬環境存儲的目錄             
if [ -e $HOME/.local/bin/virtualenvwrapper.sh ];then
   source $HOME/.local/bin/virtualenvwrapper.sh 
else if [ -e /usr/local/bin/virtualenvwrapper.sh ];then
         source /usr/local/bin/virtualenvwrapper.sh
    fi                      
fi                                                                                                                                                          
export PIP_VIRTUALENV_BASE=$WORKON_HOME                                     export PIP_RESPECT_VIRTUALENV=true

啓動 virtualenvwrapper: source ~/.bashrc  獲得以下輸出：

veelion@gtx:~/opencv$ source ~/.bashrc
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/premkproject
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/postmkproject
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/initialize
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/premkvirtualenv
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/postmkvirtualenv
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/prermvirtualenv
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/postrmvirtualenv
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/predeactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/postdeactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/preactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/postactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/get_env_details

使用方法

使用virtualenvwrapper —help 查看全部命令，經常使用的有：

• 建立基本環境：mkvirtualenv [環境名]
• 刪除環境：rmvirtualenv [環境名]
• 激活環境：workon [環境名]
• 退出環境：deactivate
• 列出全部環境：workon 或者 lsvirtualenv -b

建立Python3.6的虛擬環境

veelion@gtx:~$ mkvirtualenv -p python3.6 py3.6
Running virtualenv with interpreter /usr/bin/python3.6
Using base prefix '/usr'
New python executable in /home/veelion/.virtualenvs/py3.6/bin/python3.6
Also creating executable in /home/veelion/.virtualenvs/py3.6/bin/python
Installing setuptools, pip, wheel...done.
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/py3.6/bin/predeactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/py3.6/bin/postdeactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/py3.6/bin/preactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/py3.6/bin/postactivate
virtualenvwrapper.user_scripts creating /home/veelion/.virtualenvs/py3.6/bin/get_env_details

安裝numpy

workon py3.6
pip install numpy

2. 編譯安裝OpenCV 3.2

1. 安裝編譯依賴的軟件包

# 安裝讀寫不一樣圖片類型的庫:
sudo apt-get install libjpeg8-dev libtiff4-dev libjasper-dev libpng12-dev

# 安裝讀取視頻格式的庫:
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev

# 安裝GTK庫以使用OpenCV的GUI:
sudo apt-get install libgtk2.0-dev

# 安裝用來優化一些OpenCV內部函數的庫，好比矩陣操做:
sudo apt-get install libatlas-base-dev gfortran liblapacke-dev

2. 編譯OpenCV 
下載並解壓源碼：

wget https://github.com/opencv/opencv/archive/3.2.0.tar.gz -O opencv.tar.gz
wget https://github.com/opencv/opencv_contrib/archive/3.2.0.tar.gz -O opencv_contrib.tar.gz
tar zxf opencv.tar.gz
tar zxf opencv_contrib.tar.gz

編譯：

cd opencv-3.2.0
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_C_EXAMPLES=OFF \
    -D INSTALL_PYTHON_EXAMPLES=OFF \
-D WITH_IPP=OFF \
-DBUILD_opencv_dnn=OFF \
    -D OPENCV_EXTRA_MODULES_PATH=~/opencv/opencv_contrib-3.2.0/modules \
    -D BUILD_EXAMPLES=OFF ..

make -j4 # 編譯時間好長啊，這仍是四核一塊兒編譯呢

安裝

編譯沒有出錯的話，就能夠安裝了：

sudo make install
sudo ldconfig

以上命令會安裝OpenCV的python模塊到:

(py3.6) veelion@gtx:~/opencv/opencv-3.2.0/build$ ls /usr/local/lib/python3.6/site-packages/
cv2.cpython-36m-x86_64-linux-gnu.so

把以上.so文件連接到py3.6虛擬環境下：

(py3.6) veelion@gtx:~$ cd ~/.virtualenvs/py3.6/lib/python3.6/site-packages/
(py3.6) veelion@gtx:~/.virtualenvs/py3.6/lib/python3.6/site-packages$ ln -s /usr/local/lib/python3.6/site-packages/cv2.cpython-36m-x86_64-linux-gnu.so cv2.so

測試OpenCV的安裝

veelion@gtx:~$ workon py3.6
(py3.6) veelion@gtx:~$ python
Python 3.6.1 (default, Mar 22 2017, 10:05:53) 
[GCC 5.4.1 20170304] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>> cv2.__version__
'3.2.0'