Question

在Linux shell上输入*** Starting uWSGI 2.0.17.1 (32bit) on [Wed Nov 21 03:52:10 2018] *** compiled with version: 6.3.0 20170516 on 21 November 2018 02:28:06 os: Linux-4.14.78-v7+ #1156 SMP Tue Oct 23 14:34:39 BST 2018 nodename: pulsar machine: armv7l clock source: unix detected number of CPU cores: 4 current working directory: /var/log/uwsgi detected binary path: /usr/local/bin/uwsgi !!! no internal routing support, rebuild with pcre support !!! uWSGI running as root, you can use --uid/--gid/--chroot options *** WARNING: you are running uWSGI as root !!! (use the --uid flag) *** *** WARNING: you are running uWSGI without its master process manager *** your processes number limit is 5918 your memory page size is 4096 bytes detected max file descriptor number: 1024 lock engine: pthread robust mutexes thunder lock: disabled (you can enable it with --thunder-lock) uwsgi socket 0 bound to UNIX address /home/bryan/Development/www/lab_app/lab_app_uwsgi.sock fd 3 uWSGI running as root, you can use --uid/--gid/--chroot options *** WARNING: you are running uWSGI as root !!! (use the --uid flag) *** Python version: 2.7.13 (default, Sep 26 2018, 18:42:22) [GCC 6.3.0 20170516] Set PythonHome to /home/bryan/Development/www/lab_app ImportError: No module named site时，将显示欢迎消息：

python

这些行是从哪里来的？是在编译或安装过程中确定的吗？

我在系统上有另一个[root@localhost ~]# python Python 2.7.5 (default, Nov 20 2015, 02:00:19) [GCC 4.8.5 20150623 (Red Hat 4.8.5-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information.可执行文件版本和一组库，但是当我输入python时，它也显示与上述相同的欢迎消息。

谢谢

更新：

我使用绝对路径启动另一个版本的python。刚刚发现欢迎消息的内容与sys.version和sys.platform相同。但是，如果我将其他版本的python复制到另一台Linux计算机B，并且仍然使用绝对路径来运行它。我得到

python

此欢迎消息与机器B的python相同。

Answer 1

编辑：C版本源代码类似于： https://github.com/python/cpython/blob/7e4db2f253c555568d56177c2fd083bcf8f88d34/Modules/main.c#L705

if (!Py_QuietFlag && (Py_VerboseFlag ||
                    (command == NULL && filename == NULL &&
                     module == NULL && stdin_is_interactive))) {
    fprintf(stderr, "Python %s on %s\n",
        Py_GetVersion(), Py_GetPlatform());
    if (!Py_NoSiteFlag)
        fprintf(stderr, "%s\n", COPYRIGHT);
}

其中Py_GetVersion()返回基于MACRO的版本

https://github.com/python/cpython/blob/7e4db2f253c555568d56177c2fd083bcf8f88d34/Include/patchlevel.h#L26

/* Version as a string */
#define PY_VERSION          "3.7.0a0"

所以它是由编译时间决定的，您可能把PATH弄乱了吗？

旧答案，实际上只是一个python模块

https://github.com/python/cpython/blob/7e4db2f253c555568d56177c2fd083bcf8f88d34/Lib/code.py#L214

    if banner is None:
        self.write("Python %s on %s\n%s\n(%s)\n" %
                   (sys.version, sys.platform, cprt,
                    self.__class__.__name__))
    elif banner:
        self.write("%s\n" % str(banner))

不确定这是否能回答您的问题，但仍然很有趣。

Answer 2

我终于找到了原因。第二个python二进制文件在启动时加载.so文件，并按以下方式加载libpython：

libpython2.7.so.1.0 => /lib64/libpython2.7.so.1.0 (0x00007f087cf58000)

这与我的系统python相同。将LD_LIBRARY_PATH设置为第二个python的lib目录后，我可以看到正确的欢迎消息。

交互式python解释器的欢迎消息来自何处？

2 个答案: