Take a Sudoku Puzzle Generated by my algorithm.
Instructions for generating a valid puzzle is the same as solving a constrained n^2 x n^2
Such as this one.
----Take the top left n x n box and enter it into my algorithm and I promise you it will provide correct solution!


[123]
[456]
[789]

123456789
456789100
789100456
004567891
567891004
891004567
045678912
678910045
910045678

And provide this n x n box into my Algorithm as follows [1,2,3,4,5,6,7,8,9](generates valid grid and solves constrained)
Note: For grids larger than 9 x 9 please use additonal brackets for readablity. eg. [[01],[02],[03],....]
Also, please remember that you need to know multiplication to output a properly mapped n^2 x n^2. For example, a 25 x 25
should be a 5 x 5 for the inputs as follows

For x, x = 5

For e, e = 25

for f, f = 5

print('enter with [1,2,3...] brackets')
tup = input()[1:-1].split(',')
    #Input required to map out valid n x m or n^2 x n^2 Sudoku Grid
x = input('Enter mapping valid Sudoku eg. 3 for 9 x 9:')
e = input('Enter 9 for 9 x 9 ...12 for 12 x 12:')
f = input('Enter 3 if its a 9 x 9 ... n^2 x n^2:')
x = int(x)
e = int(e)
f = int(f)
    #Manipulation of Elements to prepare valid grid
squares = []
for i in range(len(tup)):
      squares.append(tup[i:] + tup[:i])
        
        #Everything below here is just printing
for s in range(x):
          for d in range(0,e,f):
            for si in range(s,e,f):
              for li in range(d,d+f):
                print(squares[si][li], end = '')
            print('')
            
Output of valid Solution

123456789
456789123
789123456
234567891
567891234
891234567
345678912
678912345
912345678

Spoiler- This Algorithm doesn't just solve constrained 9 x 9. I'm thinking evil for 50x25. Rules will be shared in Part-two for correctly solving 50x25

Update:-For the code to map out grids/solve puzzles correctly you must know the proper inputs.
Remember, the rules for a *12 x 12*. it would be *3 x 4* squares. And so on. 
You'll have to know how a valid Sudoku grid would map out for a n x n. eg. *9 x 9* would be *3 x 3*.


There's no reason to downvote working code. I find the reason quite confusing actually. This is on topic.
Here's the link to the grid https://cdn.hackaday.io/files/1652867071596224/output.txt
Working code linked. https://repl.it/repls/TubbyPrestigiousFirm