def board(inp):

if(inp == []):

return []

verify_board(inp)

rowlen = len(inp[0])

collen = len(inp)

b = [list(r) for r in inp]

for i1 in range(collen):

for i2 in range(rowlen):

if b[i1][i2] != ' ':

continue

low = max(i2 - 1, 0)

high = min(i2 + 2, rowlen + 2)

cnt = inp[i1][low:high].count('*')

if(i1 > 0):

cnt += inp[i1 - 1][low:high].count('*')

if(i1 < collen - 1):

cnt += inp[i1 + 1][low:high].count('*')

if cnt == 0:

continue

b[i1][i2] = str(cnt)

return ["".join(r) for r in b]

def verify_board(inp):

# Rows with different lengths

rowlen = len(inp[0])

if not all(len(r) == rowlen for r in inp):

raise ValueError("Invalid board")

# Unknown character in board

cset = set()

for r in inp:

cset.update(r)

if cset - set(' *'):

raise ValueError("Invalid board")