Creating a Grid and Putting a "fish" in it

I am creating a game of "Carpet Fish", I have my code for my 2x2 grid, but I am not sure how to randomly put my "fish" in one of the cells or the "fishing line" and to check if they are in the same grid.

I am doing this with classes, and I am still trying to figure them out. Here is the code I currently have.

import random

class Coordinate:
    '''
    '''
    def __init__(self, row, col):
        ''' 

        '''
        self.row = row 
        self.col = col

    def __str__(self):
        '''

        '''
        return "(%d, %d)" %(self.row, self.col)

class Cell:
    '''

    '''

    options = [" ", "F", "*", "F*"]
    def __init__(self, row, col):
        '''

        '''
        self.coords = Coordinate(row, col)
        self.fish = ""
        self.contains_line = False



    def __str__(self):
        '''
        '''
        return "%s"%(self.options)




class CarpetSea:
    '''

    '''
    num_of_fish = 0 
    total_time = 0 

    def __init__(self, N):
        '''

        '''
        self.N = N
        N = 2
        self.grid = []
        for i in range(self.N):
            row = []
            for j in range(self.N):
                cell = Cell(i, j)
                row.append(cell)
            self.grid.append(row)

        self.available_fish = ["Salmon", "Marlin", "Tuna", "Halibut"]
        self.celloptions = [" ", "*", "S", "S*", "M", "M*", "T", "T*", "H", "H*"]

    def __str__(self):
        '''
        returns a string representation of a CarpetSea, i.e. display the organized contents of each cell. 
        Rows and columns should be labeled with indices.

        Example (see "Example Run" in the PA8 specs for more):
          0  1  
        --------
        0|M |  |
        --------
        1|  |* |
        --------

        Note: call Cell's __str__() to get a string representation of each Cell in grid
        i.e. "M " for Cell at (0,0) in the example above
        '''
        return " 0  1  \n -------- \n 0| %s  | %s  | \n -------- \n 1| %s  | %s  | \n -------- "%(self.celloptions)         
    def randomly_place_fish(self):
        '''
        randomly selects coordinates of a cell and randomly selects a fish from the available_fish list attribute. 
        Marks the cell as containing the fish.
        '''
        random_fish = random.choice(self.grid)
        return random_fish

    def drop_fishing_line(self, users_coords):
        '''
        accepts the location of the user's fishing line (a Coordinate object). 
        Marks the cell as containing the line.
        '''
        self.coords = int(input("Please enter the coordnate that you wihsh to place your line: "))

        #this sould put the two numbers in a list
        self.coords.split()

    def check_fish_caught(self):
        '''
        If the cell containing the fishing line also contains a fish, returns the fish. 
        Otherwise, return False.
        '''


        if self.fish in self.coords:
            return True
        else:
            return False



def main():

    '''

    '''


main()

I'm not sure how to get the str funtion in CarpetSea to display the correct values, because they change depending on the user input.

Also I am not sure how to bug check with classes, because I do not know how to run individual things, such as the grid, or randomly generating a cell.