Sublime Plugin to convert frequent edits

context.sublime-menu

[
{ 
    "caption": "Convert", 
    "id": "convert", 
    "children":
    [
    {
    "caption": "Convert",
    "command": "convert"
    },
    {
    "caption": "Undo Convert",
    "command": "undo"
    }
    ]
}
]

Sublime-Plugin.py

# Sublime Plugin created for stackoverflow answer.
# https://stackoverflow.com/questions/49213489/sublime-text-and-python-plugin-how-to-incorporate-a-python-code-with-a-for-loop
import sublime, sublime_plugin, re, string   #import the required modules

class ConvertCommand(sublime_plugin.TextCommand): #create Text Command
    def run(self, edit):   #implement run method
        for region in self.view.sel():  #get user selection
            if not region.empty():  #if selection not empty then
                s = self.view.substr(region)  #assign s variable the selected region
                replace = '\n'.join([' '.join(para.splitlines()) for para in s.split('\n\n')])
                self.view.replace(edit, region, replace) #replace content in view


class UndoCommand(sublime_plugin.TextCommand): #create Text Command
    def run(self, edit):   #implement run method
        for region in self.view.sel():  #get user selection
            if not region.empty():  #if selection not empty then
                s = self.view.substr(region)  #assign s variable the selected region
                replace = '\n'.split([' '.join(para.splitlines()) for para in s.split('\n\n')])
                self.view.replace(edit, region, replace) #replace content in view

Usage

https://i.stack.imgur.com/kzvIn.png

Just save it in ~/Library/Application Support/Sublime Text 3/Packages/User/convert.py. 
menu should be saved as context.sublime-menu in the same path

Select the text to Convert:
Right Click -> Select "Convert"
Right Click -> Select "Undo" to Undo convert