entityMap|blocks|key|9bsmg|text|通常，您可以使用命令行参数来指定这一点|type|unstyled|depth|inlineStyleRanges|entityRanges|data|f4hlo|python3.7+-X+utf8|code-block|syntax|js|b6j19|如果要从环境变量启用UTF-8模式：|6jlp4|export+PYTHONUTF8=1++#+linux+/+macOS
set+PYTHONUTF8=1++#+windows|javascript|8v02l|它应该被设置之前进入Python运行时。^0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|O|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|P|9|@]|A|@]|B|$F|G]]|$2|H|4|I|6|7|8|Q|9|@]|A|@]|B|$]]|$2|J|4|K|6|E|8|R|9|@]|A|@]|B|$F|L]]|$2|M|4|N|6|7|8|S|9|@]|A|@]|B|$]]]]

Usually you would specify this with a command line argument

<pre><code>python3.7 -X utf8
</code></pre>

If you want to enable UTF-8 mode from environment variable:

<pre><code>export PYTHONUTF8=1 # linux / macOS
set PYTHONUTF8=1 # windows
</code></pre>

It should be set before entering the Python runtime.

entityMap|blocks|key|b1id4|text|您可以使用以下命令从技术上设置它os.environ["PYTHONUTF8"]+=+"on"|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|8o1vr|(值并不重要)，但这不会影响正在运行的脚本。当您在Python脚本中执行此操作时，Python已经启动并检查了这个变量，但没有找到它，因此默认情况下没有使用UTF-8编码。不过，它会影响您从脚本启动的任何Python解释器。|eqfnd|环境变量的要点是设置它之前启动Python脚本。执行此操作的方式与设置任何其他环境变量的方式相同。您没有提到您使用的是什么操作系统，但是在Linux上，您通常会将适当的命令添加到~/.bash_profile..。在Windows上，您可以使用系统属性对话框的高级页面上的按钮来设置它们。|4jbbs|显然，如果您还没有设置这个环境变量，那么您将无法在系统的环境变量列表中找到它。^0|G|V|0|0|2H|F|0^^$0|$]|1|@$2|3|4|5|6|7|8|M|9|@$A|N|B|O|C|D]]|E|@]|F|$]]|$2|G|4|H|6|7|8|P|9|@]|E|@]|F|$]]|$2|I|4|J|6|7|8|Q|9|@$A|R|B|S|C|D]]|E|@]|F|$]]|$2|K|4|L|6|7|8|T|9|@]|E|@]|F|$]]]]

You can technically set it using <code>os.environ["PYTHONUTF8"] = "on"</code> (the value doesn't matter), but this won't affect the running script. By the time you do it in a Python script, Python has already started and checked for this variable, didn't find it, and therefore isn't using UTF-8 encoding by default. It would affect any Python interpreter you launched from your script, though.

The point of the environment variable is to set it before you launch your Python script. You do this in the same way you would set any other environment variable. You don't mention what OS you're using, but on Linux, you generally add the appropriate command to <code>~/.bash_profile</code>. On Windows, you set them using a button on the Advanced page of the System Properties dialog.

Obviously you won't find this environment variable in your system's list of environment variables if you haven't set it yet.

entityMap|0|type|HR|mutability|IMMUTABLE|data|1|2|LINK|MUTABLE|url|https://docs.python.org/3.7/using/cmdline.html#environment-variables|blocks|key|8g8of|text|要访问环境变量，并在您的平台允许的情况下对其进行修改(+Windows和所有流行的Unixes都会这样做)，只需使用os.environ..。|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|30vfg|但是，这不会有任何好处，除非您尝试为要启动的Python子进程设置环境变量subprocess或者类似的东西。Python在启动时读取它的环境变量，使用它们来获取配置信息，并且以后不会再次检查它们。|bstgi|----|atomic|d18kn|这些环境变量(和命令行标志)的目的是在shell、启动器脚本等中设置它们，以便在Python启动时可以使用它们，而不是从Python内部设置它们。|7tsvl|通常情况下，如果你需要这个设置，你会需要它的全局，所以你会想要在你的shell配置文件脚本(对于Linux)，你的操作系统的环境变量的GUI+(对于Windows)，或者两者都设置(对于macOS-尽管在Mac上，一切都已经保证被设置为UTF-8，我相信即使你设法打破了它，Python也会忽略它)。(对于macOS-尽管在Mac上，一切都已经保证被设置为UTF-8，我相信即使你设法打破了它，Python也会忽略它)。|4rpqq|您不会在现有的环境变量列表中找到它(除非您使用的是一个不寻常的Linux发行版，它对区域设置做了一些奇怪的操作，但需要默认的Python来忽略它们)，但这并不重要；您可以添加任何想要的环境变量。|e7civ|8kn52|但是，如果您想要动态更改某些内容，虽然您不能通过设置环境变量来实现，但您也不需要这样做。|199h3|正如文档所解释的，它控制的是设置文件系统编码、首选编码和stdio文件编码。|syntax|javascript|bdpqh|前两个，您只需在中调用相同的函数sys和locale随时设置它们。|1la2q|如果你还想改变stdio文件，那就有点棘手了。我相信让动态更改这些文件的编码变得更容易的建议被拒绝或推迟了，所以你唯一能做的就是用包装在相同文件描述符周围的新文件对象来替换它们，它看起来像这样(目前还没有测试)：|9r81a|sys.stdout+=+open(sys.stdout.fileno(),+'w',+encoding='utf-8',+errors='surrogateescape')
sys.stderr+=+open(sys.stderr.fileno(),+'w',+encoding='utf-8',+errors='backslashescape')
sys.stdin+=+open(sys.stdin.fileno(),+'r',+encoding='utf-8',+errors='surrogateescape')|code-block|lpqh|如果您已经将任何内容打印到stdout，或者输入/通过管道将任何内容输入到stdin，则可能需要flush一切都是第一位的。|1jr4m|我所知道的唯一剩下的问题是sys.argv和os.environ|6tdcb|将(至少在Unix上)已经用错误的编码进行了解码。在设置默认编码之前，您可以通过重新编码和重新解码来修复args。我认为这使用了区域设置，所以它看起来应该是这样的：|a0ltt|sys.argv+=+[arg.encode(locale.getpreferredencoding(),+errors='surrogateescape').decode('utf8',+errors='surrogateescape')+for+arg+in+sys.argv]|js|4hu3r|修复环境有点棘手，因为如果您尝试变异os.environ它将做一个putenv|88p6i|那就叫你不想要的吧。如果这是一个问题，最好的选择可能是制作一个转码副本environ并将其用于查找，并显式地将其传递给子进程，等等。^0|1M|A|0|11|A|0|0|4|0|0|0|0|0|0|4|1|0|0|2|2|2|0|G|3|K|6|0|0|0|1C|5|0|D|8|M|A|0|0|0|I|A|X|6|0|Z|7^^$0|$1|$2|3|4|5|6|$]]|7|$2|3|4|5|6|$]]|8|$2|9|4|A|6|$B|C]]]|D|@$E|F|G|H|2|I|J|1S|K|@$L|1T|M|1U|N|O]]|P|@]|6|$]]|$E|Q|G|R|2|I|J|1V|K|@$L|1W|M|1X|N|O]]|P|@]|6|$]]|$E|S|G|T|2|U|J|1Y|K|@]|P|@$L|1Z|M|20|E|21]]|6|$]]|$E|V|G|W|2|I|J|22|K|@]|P|@]|6|$]]|$E|X|G|Y|2|I|J|23|K|@]|P|@]|6|$]]|$E|Z|G|10|2|I|J|24|K|@]|P|@]|6|$]]|$E|11|G|T|2|U|J|25|K|@]|P|@$L|26|M|27|E|28]]|6|$]]|$E|12|G|13|2|I|J|29|K|@]|P|@]|6|$]]|$E|14|G|15|2|I|J|2A|K|@]|P|@$L|2B|M|2C|E|2D]]|6|$16|17]]|$E|18|G|19|2|I|J|2E|K|@$L|2F|M|2G|N|O]|$L|2H|M|2I|N|O]]|P|@]|6|$]]|$E|1A|G|1B|2|I|J|2J|K|@]|P|@]|6|$]]|$E|1C|G|1D|2|1E|J|2K|K|@]|P|@]|6|$16|17]]|$E|1F|G|1G|2|I|J|2L|K|@$L|2M|M|2N|N|O]]|P|@]|6|$]]|$E|1H|G|1I|2|I|J|2O|K|@$L|2P|M|2Q|N|O]|$L|2R|M|2S|N|O]]|P|@]|6|$]]|$E|1J|G|1K|2|I|J|2T|K|@]|P|@]|6|$]]|$E|1L|G|1M|2|1E|J|2U|K|@]|P|@]|6|$16|1N]]|$E|1O|G|1P|2|I|J|2V|K|@$L|2W|M|2X|N|O]|$L|2Y|M|2Z|N|O]]|P|@]|6|$]]|$E|1Q|G|1R|2|I|J|30|K|@$L|31|M|32|N|O]]|P|@]|6|$]]]]

To access environment variables, and modify them if your platform allows it (which Windows and all popular Unixes do), just use <code>os.environ</code>.

However, this isn’t going to do any good, unless you’re trying to set the environment variable for Python child processes that you’re launching with <code>subprocess</code> or the like. Python reads its environment variables at startup, uses them to pick up configuration information, and doesn’t check them again later.

<hr>

The point of these environment variables (and command-line flags) is to set them in your shell, launcher script, etc., so they’re available when Python starts, not to set them from within Python.

Normally, if you need this setting, you’re going to need it globally, so you’ll want to set it in your shell profile script (for Linux), your OS’s GUI for environment variables (for Windows), or both (for macOS—although on Mac, everything is already guaranteed to be set to UTF-8, and I believe even if you manage to break that somehow, Python will ignore it).

You’re not going to find this in your existing list of environment variables (unless maybe you’re on an unusual Linux distro that does something odd with the locale settings but needs its default Python to ignore them), but that doesn’t matter; you can add any environment variables you want.

<hr>

But if you want to change things on the fly, while you can’t do that by setting an environment variable, you don’t need to, either.

As <a href="https://docs.python.org/3.7/using/cmdline.html#environment-variables" rel="nofollow noreferrer">the docs</a> explain, what it controls is setting the filesystem encoding, preferred encoding, and stdio files encoding.

The first two, you can just call the same functions in <code>sys</code> and <code>locale</code> to set them at any time.

If you also want to change the stdio files, that’s a bit trickier. I believe the proposal to make it easier to change the encoding for these files on the fly was rejected or deferred, so the only thing you can do is replace them with new file objects wrapped around the same file descriptor, which looks something like this (untested for now):

<pre><code>sys.stdout = open(sys.stdout.fileno(), 'w', encoding='utf-8', errors='surrogateescape')
sys.stderr = open(sys.stderr.fileno(), 'w', encoding='utf-8', errors='backslashescape')
sys.stdin = open(sys.stdin.fileno(), 'r', encoding='utf-8', errors='surrogateescape')
</code></pre>

If you’ve already printed anything to stdout or typed/piped anything into stdin, you may need to <code>flush</code> everything first.

The only remaining issue that I know of is that <code>sys.argv</code> and <code>os.environ</code> will (at least on Unix) have already been decoded with the wrong encoding. You can fix the args by reencoding and redecoding before setting the default encodings. I think this uses the locale settings, so it would look like:

<pre><code>sys.argv = [arg.encode(locale.getpreferredencoding(), errors='surrogateescape').decode('utf8', errors='surrogateescape') for arg in sys.argv]
</code></pre>

Fixing the environment is a bit trickier, because if you try to mutate <code>os.environ</code> it’s going to do a <code>putenv</code> call that you don’t want. If this is an issue, the best option is probably to make a transcoded copy of <code>environ</code> and use that for lookups, and explicitly pass it to subprocess, etc.

entityMap|blocks|key|98n36|text|是的，我在窗口上尝试了各种组合。它非常繁琐--如果你的环境变量中有一个引号或任何东西，它就会出错。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1r99s|从阅读源代码来看，它是非常特殊的。|f9ka|在windows上，它必须是set+PYTHONUTF8=1|offset|length|style|CODE|cnlfj|确保没有引号或任何东西。|2lt2f|if+(opt)+{
++++if+(strcmp(opt,+"1")+==+0)+{
++++++++config->utf8_mode+=+1;
++++}
++++else+if+(strcmp(opt,+"0")+==+0)+{
++++++++config->utf8_mode+=+0;
++++}
++++else+{
++++++++return+_PyStatus_ERR("invalid+PYTHONUTF8+environment+"
++++++++++++++++++++++++++++"variable+value");
++++}
++++return+_PyStatus_OK();
}|code-block|syntax|javascript^0|0|0|E|G|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|R|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|S|9|@]|A|@]|B|$]]|$2|E|4|F|6|7|8|T|9|@$G|U|H|V|I|J]]|A|@]|B|$]]|$2|K|4|L|6|7|8|W|9|@]|A|@]|B|$]]|$2|M|4|N|6|O|8|X|9|@]|A|@]|B|$P|Q]]]]

Yeah I tried various combinations on windows. It's very fussy - if you have a quote or anything in your environment variable it will error out.
From reading the source it's very particular.
on windows it must be
<code>set PYTHONUTF8=1</code>
Make sure no quotes or anything.
<pre class="lang-c prettyprint-override"><code>if (opt) {
 if (strcmp(opt, &quot;1&quot;) == 0) {
 config-&gt;utf8_mode = 1;
 }
 else if (strcmp(opt, &quot;0&quot;) == 0) {
 config-&gt;utf8_mode = 0;
 }
 else {
 return _PyStatus_ERR(&quot;invalid PYTHONUTF8 environment &quot;
 &quot;variable value&quot;);
 }
 return _PyStatus_OK();
}
</code></pre>

Python 3.7 introduced the PYTHONUTF8 environment variable to enable UTF-8 encoding by default. How do I set this variable from within a Python program? (I can't find it in my operating system's list of environment variables.)

How do I set the PYTHONUTF8 environment variable to enable UTF-8 encoding by default in Python?

 Python3.7引入了PYTHONUTF8环境变量来默认启用UTF8编码。如何在Python程序中设置此变量？(我在操作系统的环境变量列表中找不到它。)

问如何在PYTHONUTF8中将环境变量设置为默认启用UTF8编码？
EN

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问如何在PYTHONUTF8中将环境变量设置为默认启用UTF8编码？EN