PYNQ-Z2平台&Ubuntu更新Python3后ss

PYNQ-Z2自带python3.6，苦于没有可用的TensorFlow安装包，但是找到了python3.4版本对应的armv7版的TensorFlow，只能自己再安装python3.4。
编译安装完Python3.4之后，使用pip3安装python库，发现了如下报错：
（发现网上很多Ubuntu更新python3后出现此问题）

pip3 is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting numpy
Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.",)': /simple/numpy/
.
.
.
Could not fetch URL https://pypi.python.org/simple/numpy/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/numpy/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.",)) - skipping
Could not find a version that satisfies the requirement numpy (from versions: )
No matching distribution found for numpy

网上找了很多，大多数解决办法是

./configure --with-ssl
... ...
configure: WARNING: unrecognized options: --with-ssl

然而并没有什么用！
参考https://blog.csdn.net/yuezhuo_752/article/details/84140168的方法，重新安装openssl，但是由于PYNQ是arm平台，编译安装太慢太慢了。。。

终于安装完了，重新编译python3.4，仍然报错！！！崩溃。。。

然后参考http://www.cnblogs.com/minglee/p/9232673.html的方法，安装openssl相关的一堆东西，然而找不到！！

apt-get install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel

但是他的思路启发了我，我开始查看setup.py文件

        # Detect SSL support for the socket module (via _ssl)
        search_for_ssl_incs_in = [
                              '/usr/local/ssl/include',
                              '/usr/contrib/ssl/include/'
                             ]
        ssl_incs = find_file('openssl/ssl.h', inc_dirs,
                             search_for_ssl_incs_in
                             )
        if ssl_incs is not None:
            krb5_h = find_file('krb5.h', inc_dirs,
                               ['/usr/kerberos/include'])
            if krb5_h:
                ssl_incs += krb5_h
        ssl_libs = find_library_file(self.compiler, 'ssl',lib_dirs,
                                     ['/usr/local/ssl/lib',
                                      '/usr/contrib/ssl/lib/'
                                     ] )
        if (ssl_incs is not None and
            ssl_libs is not None):
            exts.append( Extension('_ssl', ['_ssl.c'],
                                   include_dirs = ssl_incs,
                                   library_dirs = ssl_libs,
                                   libraries = ['ssl', 'crypto'],
                                   depends = ['socketmodule.h']), )
        else:
            missing.append('_ssl')

其中：inc_dirs = self.compiler.include_dirs + ['/usr/include']
          add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
          add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')

然后开始检查系统内是不是存在这两个头文件
可喜的是存在ssl.h这个文件

root@pynq:/usr/include# cd openssl/
root@pynq:/usr/include/openssl# ls
aes.h       cms.h       ecdsa.h   md5.h       rand.h       ssl3.h
asn1.h      comp.h      ec.h      mdc2.h      rc2.h        ssl.h
.
.
.

可悲的是 并没有krb5.h ！

开始解决没有krb5.h的问题，发现需要安装kerberos套件，参考https://www.jianshu.com/p/fc2d2dbd510b

未完待续....