前言
python安装paddleocr时报错“no module patch_ng”的解决办法。

错误信息

在使用python安装paddleocr时，可能会遇到一下错误：

Collecting lmdb (from paddleocr>=2.0.1)
  Using cached lmdb-1.4.1.tar.gz (881 kB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error

  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [14 lines of output]
      Traceback (most recent call last):
        File "C:\Users\rongjv\AppData\Local\Temp\pip-install-jbuy_u9z\lmdb_c1e18797ceef4450879d581bb475caa1\setup.py", line 92, in <module>
          import patch_ng as patch
      ModuleNotFoundError: No module named 'patch_ng'
     
      During handling of the above exception, another exception occurred:

提示缺少patch_ng模块，patch_ng模块可能是lmdb所需，但是在附带安装时总是不成功，这时候不用执着，先手动安装patch_ng试试：

pip install patch_ng
Collecting patch_ng
  Downloading patch-ng-1.17.4.tar.gz (17 kB)
  Preparing metadata (setup.py) ... done
Building wheels for collected packages: patch_ng
  Building wheel for patch_ng (setup.py) ... done
  Created wheel for patch_ng: filename=patch_ng-1.17.4-py3-none-any.whl size=16101 sha256=e18a153685c4c150e3088294fa249f96c8e9d5473cd3d43aea33aef33ebc9c9c
  Stored in directory: c:\users\rongjv\appdata\local\pip\cache\wheels\c0\ca\79\d6c49e498d31e473f26449c5aaa3ffdeb4d9d74b48407f8067      
Successfully built patch_ng
Installing collected packages: patch_ng
Successfully installed patch_ng-1.17.4

可以看到，单独安装patch_ng模块成功，然后再次安装paddleocr：

Collecting lmdb (from paddleocr>=2.0.1)
  Using cached lmdb-1.4.1.tar.gz (881 kB)
  Preparing metadata (setup.py) ... done

可以成功安装了。

注：本文为错误解决记录，参考了网络上的文章，本文权作为记录，以便于以后参考，如果恰好帮助到你，那再好不过。