本文链接：https://blog.csdn.net/ai_liuliu/article/details/95504095
安装meld
sudo apt-get install meld
启动meld
方法1、终端命令：meld&
方法2、搜索meld，如图
启动错误：
File "/usr/bin/meld", line 73, in <module>
import meld.conf
ModuleNotFoundError: No module named 'meld'
Error in sys.excepthook:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
from apport.fileutils import likely_packaged, get_recent_crashes
File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
from apport.report import Report
File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
import apport.fileutils
File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
from apport.packaging_impl import impl as packaging
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>
import apt
File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'
Original exception was:
Traceback (most recent call last):
File "/usr/bin/meld", line 73, in <module>
import meld.conf
ModuleNotFoundError: No module named 'meld'
经过几番查找，最后发现是Python版本问题，meld需要Python2的环境。因为之前研究Python，把Python的版本升级到了3.6.8，最终导致meld不能正常使用。
解决：
发现问题，就要解决问题。
1.
Switch back to Python2. You might not want to do this, as there probably was a reason for switching to Python3.
Switching back might result in other programs not working as expected.
See command update-alternatives for switching the default Python version.
去usr/bin 目录下面把python软链接改成python2的
2.
Force meld to use Python2. For doing so, open /usr/bin/meld with root rights in a text editor and change the very first line from: #!/usr/bin/python to: #!/usr/bin/python2
去usr/bin 目录，把meld文件开头加上一个2,显示的用python2就OK
有以上两种方案，个人更倾向于第二种。虽然后续如果更新meld会比较麻烦，需要重新设置，但不会影响到系统本身的Python版本，也避免引起更多令人抓狂的问题。
修改后再次启动meld，大功靠成，接下来就可以进行代码对比了。如图：
总结有些简略，请大家多多包含。
感谢 https://blog.csdn.net/yang332233/article/details/89084481