Miniconda新环境导入Pandas报错：OMP_NUM_THREADS无法转整数

使用Spyder 5.4.0搭配Miniconda3，通过conda create -n env_full anaconda创建新Python环境并在Spyder中成功激活后，numpy、matplotlib等包可正常使用，但导入pandas时触发报错：numexpr的utils.py文件尝试将环境变量OMP_NUM_THREADS的取值'5,3,2'转换为整数失败，该问题在基础环境中未出现，寻求解决方法。

完整报错堆栈 #

import pandas
Traceback (most recent call last):

  File "C:\Users\User\AppData\Local\Temp\ipykernel_25804\3648170110.py", line 1, in <module>
    import pandas

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\__init__.py", line 48, in <module>
    from pandas.core.api import (

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\api.py", line 27, in <module>
    from pandas.core.arrays import Categorical

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\arrays\__init__.py", line 1, in <module>
    from pandas.core.arrays.arrow import ArrowExtensionArray

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\arrays\arrow\__init__.py", line 1, in <module>
    from pandas.core.arrays.arrow.array import ArrowExtensionArray

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\arrays\arrow\array.py", line 42, in <module>
    from pandas.core.arraylike import OpsMixin

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\arraylike.py", line 23, in <module>
    from pandas.core.ops.common import unpack_zerodim_and_defer

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\ops\__init__.py", line 33, in <module>
    from pandas.core.ops.array_ops import (

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\ops\array_ops.py", line 50, in <module>
    import pandas.core.computation.expressions as expressions

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\computation\expressions.py", line 20, in <module>
    from pandas.core.computation.check import NUMEXPR_INSTALLED

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\core\computation\check.py", line 5, in <module>
    ne = import_optional_dependency("numexpr", errors="warn")

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\pandas\compat\_optional.py", line 141, in import_optional_dependency
    module = importlib.import_module(name)

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\numexpr\__init__.py", line 44, in <module>
    nthreads = _init_num_threads()

  File "C:\ProgramData\Miniconda3\envs\env_full\lib\site-packages\numexpr\utils.py", line 156, in _init_num_threads
    requested_threads = int(os.environ['OMP_NUM_THREADS'])

ValueError: invalid literal for int() with base 10: '5,3,2'

解决方法 #

临时修复（当前会话有效） #

在导入pandas前重置环境变量为单个整数：

import os
os.environ['OMP_NUM_THREADS'] = '1'  # 可替换为CPU核心数等合理数值
import pandas

永久修复（针对conda环境） #

1. 打开命令行，激活目标环境：conda activate env_full
2. 设置环境变量：conda env config vars set OMP_NUM_THREADS=1（替换为你需要的线程数）
3. 重启Spyder并重新激活环境，设置即可生效

系统级环境变量检查 #

若系统级OMP_NUM_THREADS被设置为逗号分隔值，需修改系统环境变量：

• 右键「此电脑」→属性→高级系统设置→环境变量
• 在系统变量或用户变量中找到OMP_NUM_THREADS，修改为单个整数（如1、4）
• 重启电脑后生效

内容的提问来源于stack exchange，提问作者Galedon