标题：[学习了解]树莓派(Raspberry PI)上的Python3.7.1，安装后用于矩阵学习及TensorF画Sin函数图，涉及到VNCServer的配置尤其是复制和开机启动相关的low安装入门
出处：向东博客 专注WEB应用 构架之美 --- 构架之美，在于尽态极妍 | 应用之美，在于药到病除
时间：Sat, 15 Dec 2018 14:53:40 +0000
作者：jackxiang
地址：http://jackxiang.com/post/9995/

内容：
sudo useradd -m -s /bin/bash xiangdong -g irdcops  #添加用户


sudo apt-get install build-essential tk-dev -y
sudo apt-get install libncurses5-dev libncursesw5-dev libreadline-dev -y
sudo apt-get install libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev -y
sudo apt-get install libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev -y
sudo apt autoremove -y


DownLoad：
https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
出现缺少库ModuleNotFoundError: No module named '_ctypes'，再次加上,关于在centos下安装python3.7.0以上版本时报错ModuleNotFoundError: No module named '_ctypes'的解决办法:

3.7版本需要一个新的包libffi-devel，安装此包之后再次进行编译安装即可。

#yum install libffi-devel -y
#make install
若在安装前移除了/usr/bin下python的文件链接依赖，此时yum无法正常使用，需要自己下载相关软件包安装，为节省读者时间，放上链接

#wget http://mirror.centos.org/centos/7/os/x86_64/Packages/libffi-devel-3.0.13-18.el7.x86_64.rpm
#rpm -ivh libffi-devel-3.0.13-18.el7.x86_64.rpm
安装完成后重新进行make install，结束后再次配置相关文件的软连接即可。
原文：https://blog.csdn.net/qq_36416904/article/details/79316972 


而Raspberry Pi读取的是libffi-dev ,如下：

sudo apt-get update -y
sudo apt-get upgrade -y
sudo apt-get dist-upgrade -y
sudo apt-get install build-essential python-dev python-setuptools python-pip python-smbus -y
sudo apt-get install libncursesw5-dev libgdbm-dev libc6-dev -y
sudo apt-get install zlib1g-dev libsqlite3-dev tk-dev -y
sudo apt-get install libssl-dev openssl -y
sudo apt-get install libffi-dev -y

来自：https://blog.csdn.net/wang725/article/details/79905612

./configure --prefix=/usr/local/python37 &&  make && make install 
Collecting pip
Installing collected packages: setuptools, pip
Successfully installed pip-10.0.1 setuptools-39.0.1
在新版本的树莓派上出现问题：
$ python
Python 3.7.0a3 (default, Jan 10 2018, 14:36:35)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.7/ssl.py", line 100, in <module>
    import _ssl             # if we can't import it, let the error propagate
ModuleNotFoundError: No module named '_ssl'
apt-get install libssl-dev openssl
修改python源码：
$ vi Modules/Setup
找到
# Socket module helper for socket(2)
#_socket socketmodule.c

# Socket module helper for SSL support; you must comment out the other
# socket line above, and possibly edit the SSL variable:
#SSL=/usr/local/ssl
#_ssl _ssl.c \
#       -DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
#       -L$(SSL)/lib -lssl -lcrypto
改為
# Socket module helper for socket(2)
_socket socketmodule.c

# Socket module helper for SSL support; you must comment out the other
# socket line above, and possibly edit the SSL variable:
#SSL=/usr/local/ssl
_ssl _ssl.c \
        -DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
        -L$(SSL)/lib -lssl -lcrypto
https://hk.saowen.com/a/0b0ad8c19b818139066b545032da2834cd5a1413d4dd86a3b43d715277d60309

#做软链接
#sudo cp /usr/bin/python /usr/bin/python2.7_bak #不用个性，系统自己也用python旧版本。
#sudo rm /usr/bin/python
sudo ln -s /usr/local/python37/bin/python3.7 /usr/bin/python3.7

#Pip用刚编译的最新的Pip3
#sudo mv /usr/bin/pip /usr/bin/pip2_bak  #不用个性，系统自己也用python旧版本。
sudo ln -s /usr/local/python37/bin/pip3 /usr/bin/pip3.7   #/usr/bin/pip3.7 -> /usr/local/python37/bin/pip3

问题：pip3 install simplejson出现：
subprocess.CalledProcessError: Command ‘(‘lsb_release’, ‘-a’)’ returned non-zero exit status 1.

解决方法
find / -name lsb_release
rm -rf /usr/bin/lsb_release
于是就好了：
/usr/local/python37/bin/pip3  install simplejson
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting simplejson
  Downloading https://files.pythonhosted.org/packages/e3/24/c35fb1c1c315fc0fffe61ea00d3f88e85469004713dab488dee4f35b0aff/simplejson-3.16.0.tar.gz (81kB)
    100% |████████████████████████████████| 81kB 73kB/s 
Successfully installed simplejson-3.16.0
You are using pip version 10.0.1, however version 18.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
pip install --upgrade pip
root@raspberrypi:/usr/local/src/Python-3.7.1# pip install --upgrade pip 
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting pip
  Downloading https://files.pythonhosted.org/packages/c2/d7/90f34cb0d83a6c5631cf71dfe64cc1054598c843a92b400e55675cc2ac37/pip-18.1-py2.py3-none-any.whl (1.3MB)
    100% |████████████████████████████████| 1.3MB 50kB/s 
Installing collected packages: pip
  Found existing installation: pip 10.0.1
    Uninstalling pip-10.0.1:
      Successfully uninstalled pip-10.0.1
Successfully installed pip-18.1
原文：https://blog.csdn.net/itdabaotu/article/details/83142918 


编译Python3.7.1教程：https://blog.csdn.net/RambleMY/article/details/82109788

安装numpy:
如果成功安装好了pip，安装numpy及其他任何Python包都非常方便了
　　运行pip install numpy
　　pip会先自动下载与我们Python版本对应的numpy-xxx.whl文件，然后安装

矩阵计算：

root@raspberrypi:/usr/local/src/Python-3.7.1# pip install numpy
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting numpy
  Downloading https://files.pythonhosted.org/packages/2d/80/1809de155bad674b494248bcfca0e49eb4c5d8bee58f26fe7a0dd45029e2/numpy-1.15.4.zip (4.5MB)
    100% |████████████████████████████████| 4.5MB 119kB/s 
Installing collected packages: numpy
  Running setup.py install for numpy ... done
Successfully installed numpy-1.15.4

>>> x = np.array([1.0, 2.0, 3.0])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'np' is not defined

>>> import numpy as np
>>> x = np.array([1.0, 2.0, 3.0])
>>> print(x)
[1. 2. 3.]
>>> type(x)
<class 'numpy.ndarray'>
>>> x = np.array([1.0, 2.0, 3.0])
>>> y = np.array([2.0, 4.0, 6.0])
>>> x + y
array([3., 6., 9.])
>>> x - y
array([-1., -2., -3.])
>>> x * y
array([ 2.,  8., 18.])
>>> print(x)
[1. 2. 3.]
>>> print(y)
[2. 4. 6.]
>>> print(x+y)
[3. 6. 9.]
>>> x / 2.0
array([0.5, 1. , 1.5])
>>> A = np.array([[1, 2], [3, 4]])   
>>> print(A)
[[1 2]
 [3 4]]
>>> A.shape
(2, 2)
>>> A.dtype
dtype('int32')
>>> B = np.array([[3, 0],[0, 6]])
>>> A + B
array([[ 4,  2],
       [ 3, 10]])
>>> A * B
array([[ 3,  0],
       [ 0, 24]])
>>> print(A)
[[1 2]
 [3 4]]
>>> A * 10
array([[10, 20],
       [30, 40]])
广播：
>>> A = np.array([[1,2],[3,4]])
>>> B = np.array([10,20])
>>> A*B
array([[10, 40],
       [30, 80]])

循环：
>>> X = np.array([[51,55],[14,19],[0,4]])
>>> for row in X:
...     print(row)
... 
[51 55]
[14 19]
[0 4]

#将X转为一维数组
>>> X = X.flatten()
>>> print (X)
[51 55 14 19  0  4]

#从X里抽取大于15的元素
>>> X > 15
array([ True,  True, False,  True, False, False])
>>> X[X>15]
array([51, 55, 19])





画曲线：
sudo su -
pip3 install matplotlib  #失败
sudo apt-get install python3-matplotlib # 安装成功，但是写代码时引用失败，如下：
>>> import matplotlib.pyplot as plt
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'matplotlib'  ，成功如下：

sudo su -  #否则会[Errno 13] 权限不够
pip install  matplotlib
pip install  sklearn   #不运行这个也能import matplotlib.pyplot as plt

import numpy as np
import matplotlib.pyplot as plt

# 生成数据
x = np.arange(0, 6, 0.1) # 以0.1为单位，生成0到6的数据
y = np.sin(x)

# 绘制图形
plt.plot(x, y)  #SecureCRT不行，有博文说它将弹出一个新窗口，显示一幅如图3-16所示的曲线，但不同的是多了几个GUI按钮做修饰。
plt.show()

以上代码在树莓派的界面上运行成功输出一个新窗口的Sina曲线。


二)VNCServer的配置尤其是复制和开机启动相关：
cat /home/irdcops/shell/vncsvr/startvncsvr.sh 
killall Xvnc >/dev/null 2>&1  
vncserver -kill :1  
rm -rf /tmp/.X*-lock  
rm -rf /tmp/.X11-unix/X*  
rm -rf /root/.vnc/*.log  
rm -rf /root/.vnc/*.pid  
vncserver :1 -geometry 1024x768  

这个是手动，二是那个能从Windows里复制进去，还得要开机启动，如下配置：

1. 安装autocutsel sudo apt-get install autocutsel
2. 打开/root/.vnc/xstartup,添加 autocutsel -fork
#!/bin/sh
xrdb $HOME/.Xresources
xsetroot -solid grey
autocutsel -fork
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession
3. 关闭VNC:    vncserver -kill :1
4. 启动VNC:    vncserver  :1

以上来自：https://www.jianshu.com/p/1cbb422cf54a



cat /etc/init.d/vncserver

#!/bin/sh
### BEGIN INIT INFO
# Provides:          vncserver
# Required-Start:    $local_fs
# Required-Stop:     $local_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start/stop vncserver
### END INIT INFO
# 第一行是告诉系统这个脚本文件通过/bin/目录下的sh来执行
# 后面几行是一些说明信息，说明这个脚本是干嘛的
# 这脚本是用来开启和关闭vncserver的
 
# More details see:
# http://www.penguintutor.com/linux/vnc
 
### Customize this entry
# Set the USER variable to the name of the user to start vncserver under
export USER='root'
### End customization required
# 导出环境变量USER='pi'
 
eval cd ~$USER
# eval表示该句扫过两次，首先将cd ~$USER替换为cd ~pi
# 接着执行cd ~pi
 
# 如果sh执行这个脚本的时候传入的第一个参数是start，就...
# 如果sh执行这个脚本的时候传入的第一个参数是stop，就...
# 如果sh执行这个脚本的时候传入的第一个参数是其他，就...
case "$1" in
  start)
    # 启动命令行。此处自定义分辨率、控制台号码或其它参数。
    su $USER -c '/usr/bin/vncserver -depth 16 -geometry 1024x768 :1'
    echo "Starting VNC server for $USER "
    ;;
  stop)
    # 终止命令行。此处控制台号码与启动一致。
    su $USER -c '/usr/bin/vncserver -kill :1'
    echo "vncserver stopped"
    ;;
  *)
    echo "Usage: /etc/init.d/vncserver {start|stop}"
    exit 1
    ;;
esac

exit 0



chmod 755 /etc/init.d/vncserver
sudo update-rc.d vncserver defaults

继续解决复制问题，如下步骤：
找不到：vncconfig,在红帽里找了一下，发现在：
rpm -qf /usr/bin/vncconfig 
tigervnc-server-minimal-1.8.0-5.el7.x86_64 ，于是推测在Raspberry Pi里也是这样，指示了下：
apt-get install  tigervnc-standalone-server
下列【新】软件包将被安装：
  libgnutls30 libhogweed4 libnettle6 libxfont2 tigervnc-common tigervnc-standalone-server
apt-get install  tigervnc-standalone-server   #之前安装了一个：  sudo apt-get install tightvncserver
 root@raspberrypi:~# vncconfig
vncconfig: unable to open display ""

stat /usr/bin/vncconfig
最近改动：2018-12-16 19:23:52.760773550 +0800

据博文，在文件/root/.vnc/xstartup,加一行 vncconfig -iconic &  ，有的说是加： vncconfig -nowin&

 cat /root/.vnc/xstartup    
#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid grey
autocutsel -fork
vncconfig -iconic &
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession



三）TensorFlow：https://www.raspberrypi.org/magpi/tensorflow-ai-raspberry-pi/
https://yq.aliyun.com/articles/623213


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