ubuntu下安装python-dev遇到的问题

安装教程（简书）

按照上面的教程， 配置完镜像源之后，

1. 安装aptitude

   sudo apt-get install aptitude
   

2. 然后用aptitude安装python-dev

   sudo aptitude install python-dev 
   

遇到下面问题：

medlen@IdeaPad:/etc/apt$ sudo apt-get install aptitude 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
aptitude is already the newest version (0.8.10-6ubuntu1).
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.

medlen@IdeaPad:/etc/apt$ sudo aptitude install python-dev 
No candidate version found for python-dev
Unable to apply some actions, aborting

说是没有找到候选的版本；

参考： https://blog.csdn.net/Lyncai/article/details/80934683

这个问题的原因是ubuntu的/etc/apt/source.list中的源比较旧了，需要更新一下

于是运行：

sudo apt-get -y update

然后遇到了新的问题：

W: GPG error: http://us.archive.ubuntu.com/ubuntu precise-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
E: The repository 'http://us.archive.ubuntu.com/ubuntu precise-updates InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

参考：https://chrisjean.com/fix-apt-get-update-the-following-signatures-couldnt-be-verified-because-the-public-key-is-not-available/

运行下面命令：

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5

之后安装python-dev：

sudo apt-get install python-dev

显示缺少依赖包

The following packages have unmet dependencies:
 python-dev : Depends: python (= 2.7.5-5ubuntu3) but it is not going to be installed
              Depends: libpython-dev (= 2.7.5-5ubuntu3) but it is not going to be installed
              Depends: python2.7-dev (>= 2.7.5-1~) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

更新软件源：

sudo apt-get update

又一个问题：

W: GPG error: http://us.archive.ubuntu.com/ubuntu precise-updates InRelease: The following signatures were invalid: 630239CC130E1A7FD81A27B140976EAF437D05B5
E: The repository 'http://us.archive.ubuntu.com/ubuntu precise-updates InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

签名无效。。。

从报错上看， 是因为访问这个路径出的问题：http://us.archive.ubuntu.com/ubuntu，这个是原始的源数据找到后删除即可；

我的这个是在

/etc/apt/sources.list.d/ 

路径下的precise-updates.list文件中，这个是因为之前执行过

echo "deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted" | sudo tee -a /etc/apt/sources.list.d/precise-updates.list

这个命令。
也就是文章开头推荐的链接里面， 第三个方法。

最后执行

sudo aptitude install python-dev 

成功！