PyO3 在使用 Anaconda 时找不到 Python 解释器

如何解决PyO3 在使用 Anaconda 时找不到 Python 解释器

考虑以下 Rust 代码：

use pyo3::prelude::*;

fn main() -> PyResult<()>{
    let gil = Python::acquire_gil();
    let py = gil.python();

    let result = py.run("print('it works')",None,None);

    if let Err(ref err) = result {
        println!("{:?}",err);
    }
    Ok(())
}

使用“标准”Python 安装，这运行良好，并打印 it works。我尝试在 Windows 上使用全新安装的 Anaconda 运行此代码，并输出以下内容：

Python path configuration:
  PYTHONHOME = (not set)
  PYTHONPATH = (not set)
  program name = 'python'
  isolated = 0
  environment = 1
  user site = 1
  import site = 1
  sys._base_executable = 'C:\\bug\\target\\debug\\bug.exe'
  sys.base_prefix = 'C:\\Users\\balog\\anaconda3'
  sys.base_exec_prefix = 'C:\\Users\\balog\\anaconda3'
  sys.executable = 'C:\\bug\\target\\debug\\bug.exe'
  sys.prefix = 'C:\\Users\\balog\\anaconda3'
  sys.exec_prefix = 'C:\\Users\\balog\\anaconda3'
  sys.path = [
    'C:\\Users\\balog\\anaconda3\\python38.zip','.\\DLLs','.\\lib','C:\\bug\\target\\debug',]
Fatal Python error: init_fs_encoding: Failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
ModuleNotFoundError: No module named 'encodings'

Current thread 0x00000e6c (most recent call first):
<no Python frame>
error: process didn't exit successfully: `target\debug\bug.exe` (exit code: 1)

似乎所有 sys 可执行文件都指向错误的位置。

Rust 环境信息：

cargo 1.50.0 (f04e7fab7 2021-02-04)
release: 1.50.0
commit-hash: f04e7fab73128592a4063983c302da788bdfaba5
commit-date: 2021-02-04

rustc 1.53.0-nightly (f82664191 2021-03-21)
binary: rustc
commit-hash: f82664191d0e8764b7435b9d72eb0e366b8b1464
commit-date: 2021-03-21
host: x86_64-pc-windows-msvc
release: 1.53.0-nightly
LLVM version: 12.0.0

PyO3 version: 0.13.2

这是conda info -a的输出：


     active environment : base
    active env location : C:\Users\balog\anaconda3
            shell level : 1
       user config file : C:\Users\balog\.condarc
 populated config files : 
          conda version : 4.9.2
    conda-build version : 3.20.5
         python version : 3.8.5.final.0
       virtual packages : __cuda=9.1=0
                          __win=0=0
                          __archspec=1=x86_64
       base environment : C:\Users\balog\anaconda3  (writable)
           channel URLs : https://repo.anaconda.com/pkgs/main/win-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/win-64
                          https://repo.anaconda.com/pkgs/r/noarch
                          https://repo.anaconda.com/pkgs/msys2/win-64
                          https://repo.anaconda.com/pkgs/msys2/noarch
          package cache : C:\Users\balog\anaconda3\pkgs
                          C:\Users\balog\.conda\pkgs
                          C:\Users\balog\AppData\Local\conda\conda\pkgs
       envs directories : C:\Users\balog\anaconda3\envs
                          C:\Users\balog\.conda\envs
                          C:\Users\balog\AppData\Local\conda\conda\envs
               platform : win-64
             user-agent : conda/4.9.2 requests/2.24.0 cpython/3.8.5 Windows/10 Windows/10.0.19041
          administrator : False
             netrc file : None
           offline mode : False

# conda environments:
#
base                  *  C:\Users\balog\anaconda3

sys.version: 3.8.5 (default,Sep  3 2020,21:29:08) [...
sys.prefix: C:\Users\balog\anaconda3
sys.executable: C:\Users\balog\anaconda3\python.exe
conda location: C:\Users\balog\anaconda3\lib\site-packages\conda
conda-build: C:\Users\balog\anaconda3\Scripts\conda-build.exe
conda-convert: C:\Users\balog\anaconda3\Scripts\conda-convert.exe
conda-debug: C:\Users\balog\anaconda3\Scripts\conda-debug.exe
conda-develop: C:\Users\balog\anaconda3\Scripts\conda-develop.exe
conda-env: C:\Users\balog\anaconda3\Scripts\conda-env.exe
conda-index: C:\Users\balog\anaconda3\Scripts\conda-index.exe
conda-inspect: C:\Users\balog\anaconda3\Scripts\conda-inspect.exe
conda-Metapackage: C:\Users\balog\anaconda3\Scripts\conda-Metapackage.exe
conda-render: C:\Users\balog\anaconda3\Scripts\conda-render.exe
conda-server: C:\Users\balog\anaconda3\Scripts\conda-server.exe
conda-skeleton: C:\Users\balog\anaconda3\Scripts\conda-skeleton.exe
conda-verify: C:\Users\balog\anaconda3\Scripts\conda-verify.exe
user site dirs: 

CIO_TEST: <not set>
CONDA_DEFAULT_ENV: base
CONDA_EXE: C:\Users\balog\anaconda3\condabin\..\Scripts\conda.exe
CONDA_EXES: "C:\Users\balog\anaconda3\condabin\..\Scripts\conda.exe"  
CONDA_PREFIX: C:\Users\balog\anaconda3
CONDA_PROMPT_MODIFIER: (base) 
CONDA_PYTHON_EXE: C:\Users\balog\anaconda3\python.exe
CONDA_ROOT: C:\Users\balog\anaconda3
CONDA_SHLVL: 1
CURL_CA_BUNDLE: <not set>
HOMEPATH: \Users\balog
PATH: C:\Users\balog\anaconda3;C:\Users\balog\anaconda3\Library\mingw-w64\bin;C:\Users\balog\anaconda3\Library\usr\bin;C:\Users\balog\anaconda3\Library\bin;C:\Users\balog\anaconda3\Scripts;C:\Users\balog\anaconda3\bin;C:\Users\balog\anaconda3;C:\Users\balog\anaconda3\Library\mingw-w64\bin;C:\Users\balog\anaconda3\Library\usr\bin;C:\Users\balog\anaconda3\Library\bin;C:\Users\balog\anaconda3\Scripts;C:\Users\balog\anaconda3\bin;C:\Users\balog\anaconda3\condabin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit;C:\Program Files\pysprint-cli\bin;C:\Users\balog\.cargo\bin;C:\Users\balog\AppData\Local\Microsoft\WindowsApps;C:\Users\balog\anaconda3\python.exe;.
PSMODULEPATH: C:\Program Files\WindowsPowerShell\Modules;C:\Windows\system32\WindowsPowerShell\v1.0\Modules
REQUESTS_CA_BUNDLE: <not set>
SSL_CERT_FILE: <not set>

有人能指出我做错了什么吗？我试过研究，但没有太多资源。

解决方法

我在我们的一个内部应用程序中遇到了与 Miniconda 类似的问题。看起来他们确实在启动时修改了一些导致我们的应用程序在启动时失败的东西，但仅针对 Miniconda。

长话短说，您需要在启动 Python 时先调用 Py_SetPath，然后再调用 Py_Initialize。

见https://github.com/python/cpython/blob/master/PC/getpathp.c

我不会假装这是一个好的解决方案，但我找到了一个解决方法。 Anaconda 设置了 ggplot(mapping = aes(x = x,y = y)) + geom_line(data = df_density0,aes(colour = "Target = 0")) + geom_line(data = df_density1,aes(colour = "Target = 1")) + scale_colour_manual( values = c("darkred","steelblue") ) 环境变量，就我而言它适合作为 CONDA_PREFIX。但是，我不确定它是否适用于任何人，我更希望有一个通用的解决方案，所以我肯定会向 PyO3 提交一个问题。我也不认为最终用户应该自己调用不安全的函数。

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