How to find knot vector if control points are known for a NURBS curve?

I have a set of control points

pts = [[849, 1181],
       [916, 1257],
       [993, 1305],
       [1082,1270], 
       [1137,1181],
       [1118,1055], 
       [993,1034], 
       [873,1061], 
       [849, 1181]]

I have the logic for generating an open knot vector:

/*
Subroutine to generate a B-spline open knot vector with multiplicity
equal to the order at the ends.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot       vector value
nplusc       = maximum value of the knot vector -- $n + c$
x()          = array containing the knot vector
*/

knot(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;
nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
    for (i = 2; i <= nplusc; i++){
        if ( (i > c) && (i < nplus2) )
            x[i] = x[i-1] + 1;
    else
            x[i] = x[i-1];


    }
}

And another one for generating periodic knot vector:

/*  Subroutine to generate a B-spline uniform (periodic) knot vector.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot vector value
nplusc       = maximum value of the knot vector -- $n + c$
x[]          = array containing the knot vector
*/

#include    <stdio.h>

knotu(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;

nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
for (i = 2; i <= nplusc; i++){
    x[i] = i-1;
}
}

I however need to generate a non-uniform knot vector in the range of [0,1]

The above algorithms result in uniform knot vectors.

Kindly suggest if there is any way to do this. It would be preferable if the code is in python

Knot vector (uniform or not) is part of the definition of a NURBS curve. So, you can actually define your own non-uniform knot vector as long as the knot vector follows the basic rules:

1) # of knot values = # of control points + order

2) All knot values must be non-decreasing. Namely, k[i] <= k[i+1].

For your example with 9 control points, you can have non-uniform knot vector like [0, 0, 0, 0, a, b, c, d, e, 1, 1, 1, 1], where 0.0 < a <= b <= c <=d <=e < 1.0 for a degree 3 B-spline curve. Of course, choosing different values for a, b, c, d and e will result in curves with different shape.