Python(3.10)

This is a simple text editor which can modify text file using python.
First of all you need to know some essential things about how this program works:

1. When you run the code, you should enter one of the main functions that've been defined.
2. There is a main loop which run while you use the program so if you want to break it you can exit easily.
3. List of all functions:

Exit
Next page
Previous page
Where
Show(n)
Append
Insert(text,line number)
Remove(n)
Replace( a , n )
Swap( a , b )
Find(a)
Find&Replace ( a , b )
Undo
Redo

Actually, It's like vim. You should work with commands.

• $exit:
  Save the final file and exit from file

• $nextpage:
  Show the next page. (all pages were seperated via "$" symbol)

• $previouspage:
  Same as next page

• $where:
  show your current page number

• $show(n):
  Show the line number n in current page

• $append:
  Insert new text at the end of current page.

• $insert(d,n):
  Insert text d at line number n

• $remove( n ):
  Remove line number n from the current page

• replace( a , n ):
  Replace text a with the text at line number n

• $swap( a , b ):
  Swap line number a with line number b

• $find(a):
  Find all possible testcases of a in whole file

• $far ( a , b ):
  Find and replace text a with text b

• $undo:
  Undo the last change

• $redo:
  Obvious