string search algorithm for 2d array

Question

So im creating a Airline counter simulation in python.

Arr = np.array( [
    ["","A","B","C","D","E","F"],
    ["1","0","0","0","0","0","0"],
    ["2","0","0","0","0","0","0"],
    ["3","0","0","0","0","0","0"],
    ["4","0","0","0","0","0","0"],
    ["5","0","0","0","0","0","0"],
    ["6","0","0","0","0","0","0"],
    ["7","0","0","0","0","0","0"],
    ["8","0","0","0","0","0","0"]
])

this is my basic airplane representation, a string 2d array, when a seat is reserved an "0" will turn into a "X". I want some type of searching algorithm (preferably some type of binary or linear search) to find the position where X is located on the array(it may have multiple "X" in the array) Example

Arr = np.array( [
    ["","A","B","C","D","E","F"],
    ["1","X","0","0","0","0","0"],
    ["2","0","0","0","0","0","0"],
    ["3","0","0","0","0","0","0"],
    ["4","0","0","0","0","0","0"],
    ["5","0","0","0","0","0","0"],
    ["6","0","0","0","0","0","0"],
    ["7","0","0","0","0","0","0"],
    ["8","0","0","X","0","0","X"]
])

An example it would be:

The occupied seats are at: (1,1), (8,3), (8,6)

Im looking for something like this or similar that works with strings and in a 2d array:

def findRow(a, n, m, k):
#a is the 2d array
#n is the number of rows
#m is the number of columns
#k is the "X"
    l = 0
    r = n - 1
    mid = 0
    while (l <= r) :
        mid = int((l + r) / 2)
         
        # we'll check the left and
        # right most elements
        # of the row here itself
        # for efficiency
        if(k == a[mid][0]): #checking leftmost element
            print("Found at (" , mid , ",", "0)", sep = "")
            return
         
        if(k == a[mid][m - 1]): # checking rightmost element
            t = m - 1
            print("Found at (" , mid , ",", t , ")", sep = "")
            return
        if(k > a[mid][0] and k < a[mid][m - 1]):    # this means the element
                                                    # must be within this row
            binarySearch(a, n, m, k, mid)    # we'll apply binary
                                            # search on this row
            return
        if (k < a[mid][0]):
            r = mid - 1
        if (k > a[mid][m - 1]):
            l = mid + 1
 
def binarySearch(a, n, m, k, x):    #x is the row number
     
    # now we simply have to apply binary search as we
    # did in a 1-D array, for the elements in row
    # number
    # x
    l = 0
    r = m - 1
    mid = 0
    while (l <= r):
        mid = int((l + r) / 2)
         
        if (a[x][mid] == k):
            print("Found at (" , x , ",", mid , ")", sep = "")
            return
        if (a[x][mid] > k):
            r = mid - 1
        if (a[x][mid] < k):
            l = mid + 1
     
    print("Element not found")