Sort INI configuration files in Python

INI files are a popular choice for creating configurations for programs. Each file contains various sections and each section contains the settings.

For example

ServerAliveInterval = 45
Compression = yes
CompressionLevel = 9
ForwardX11 = yes
User = hg
Port = 50022
ForwardX11 = no

Sometimes INI configuration files become really large and there is a need to sort them so that you can better compare different versions. The following script can sort and save the sorted version of an existing configuration file in Python 3 version.