How is work the below python code ? Please explain step by step .

Please give examples , why the two code can know the table is square or not .

(1) def checkvalid(table):

if len(table)==len(table[0]):

return True

return False

(2) def checkvalid(table):

 for i in range(len(table)): for j in range(len(table)): print(table[i][j], end = ' ') print()