Using the $2$D diffusion equation for tracer concentration $(C)$ :

$\frac{\text{d}\text{e}\text{l}\text{C}}{\text{d}\text{e}\text{l}\text{t}}-A[\frac{de{l}^{2}C}{del{x}^2}+\frac{de{l}^{2}C}{del{y}^2}]=0$

where $A$ is the horizontal diffusion coefficient and equal to $2000\frac{m^2}{s},x$ and $y$ are in units of meter and $t$

in units of second. The field of $C$ at time $t=0($initial conditions$)$ is given by

$\frac{c_{i,j}^{n+1}-c_{i,j}^{n-1}}{2t}=A[\frac{c_{i+1,j}^n-(c_{i,j}^{n+1}+c_{i,j}^{n-1})+c_{i-1,j}^n}{x^2}+\frac{c_{i,j+1}^n-(c_{i,j}^{n+1}+c_{i,j}^{n-1})+c_{i,j-1}^n}{y^2}]$

Given the boundary condition i Equ $10,$ kindly write a python code to solve equation $9$ using Using the Dufort$-$Frankel approximation given in Equ $11.$