ModuleNotFoundError: No module named ‘_bz2‘问题解决

在运行PyTorch代码的时候，报了“ModuleNotFoundError: No module named '_bz2'”错误，完整报错提示信息如下：

Traceback (most recent call last):
  File "stat_model.py", line 1, in 
    from torchstat import stat
  File "/usr/local/lib/python3.7/site-packages/torchstat/__init__.py", line 11, in 
    from torchstat.reporter import report_format
  File "/usr/local/lib/python3.7/site-packages/torchstat/reporter.py", line 1, in 
    import pandas as pd
  File "/usr/local/lib/python3.7/site-packages/pandas/__init__.py", line 55, in 
    from pandas.core.api import (
  File "/usr/local/lib/python3.7/site-packages/pandas/core/api.py", line 24, in 
    from pandas.core.groupby import Grouper, NamedAgg
  File "/usr/local/lib/python3.7/site-packages/pandas/core/groupby/__init__.py", line 1, in 
    from pandas.core.groupby.generic import (  # noqa: F401
  File "/usr/local/lib/python3.7/site-packages/pandas/core/groupby/generic.py", line 44, in 
    from pandas.core.frame import DataFrame
  File "/usr/local/lib/python3.7/site-packages/pandas/core/frame.py", line 88, in 
    from pandas.core.generic import NDFrame, _shared_docs
  File "/usr/local/lib/python3.7/site-packages/pandas/core/generic.py", line 70, in 
    from pandas.io.formats.format import DataFrameFormatter, format_percentiles
  File "/usr/local/lib/python3.7/site-packages/pandas/io/formats/format.py", line 48, in 
    from pandas.io.common import _expand_user, _stringify_path
  File "/usr/local/lib/python3.7/site-packages/pandas/io/common.py", line 3, in 
    import bz2
  File "/usr/local/lib/python3.7/bz2.py", line 19, in 
    from _bz2 import BZ2Compressor, BZ2Decompressor
ModuleNotFoundError: No module named '_bz2'

出现这个错误的原因是我用的是python3.7，但是bz2这个库是安装到了python3.6里面，所以找不到。为了解决这个问题，需要将python3.6里面的bz库拷贝到python3.7下面。具体过程如下：

1、找到python3.6路径下的bz库文件，即“_bz2.cpython-36m-x86_64-linux-gnu.so”。

ls /usr/lib/python3.6/lib-dynload/

可以看到该文件名称中的“-36m”对应的是python3.6版本。

2、切换到python3.7对应路径，将该文件复制到该目录下：

cd /usr/local/lib/python3.7/lib-dynload

sudo cp /usr/lib/python3.6/lib-dynload/_bz2.cpython-36m-x86_64-linux-gnu.so ./

3、修改文件名称，将"-36m"修改为"-37m"即可：

sudo mv _bz2.cpython-36m-x86_64-linux-gnu.so _bz2.cpython-37m-x86_64-linux-gnu.so

至此，问题解决。

 

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需要注意的是，还有一个路径/usr/lib/python3.7/lib-dynload，文件复制到该目录下面没有用，我这里需要复制到/usr/local/lib/python3.7/lib-dynload目录下。