Lab 9: bugging out

def printTable( table:list ) -> None:

""" Given a 2D list (a list of lists), print out the entries,

with each row on a new line. """

# for each row index of the table

for rowIndex in range(len(table)):

# make a string to accumulate our entries into

rowString:str = ""

# it's a list, so walk over each entry

for colIndex in range(len(table[rowIndex])):

rowString += str( table[rowIndex][colIndex] ) + "\t"

# print it!

print( rowString )

def printTables( tables:list ) -> None:

""" Given a 3D list (a list of 2D lists), print each 2D list. """

for table in tables:

printTable(table)

print( "---------------------" )

def enumerateQueens3() -> list:

boards:list = [] # to track all the boards

emptyBoard:list = [[False]*3]*3

# for every placement of a queen in row 0

for i in range( 3 ):

# make a copy of the empty board

board0:list = copyTable( emptyBoard )

# place the queen

board0[0][i] = True

# for every placement of a queen in row 1

for j in range( 3 ):

# make a copy of the board

board1:list = copyTable( board0 )

# place the queen

board1[1][j] = True

# for every placement of a queen in row 2

for k in range( 3 ):

# make a copy of the board

board2:list = copyTable( board1 )

# place the last queen

board2[2][k] = True

# add it to the list of boards

boards.append( board2 )

return boards

def copyTable( table:list ) -> list:

""" Make a copy of a 2D table and return it. """

# use an accumulator pattern to build up the copy row by row

copiedTable:list = [] # start with the empty list

# for each row of the given list

for row in table:

# the copy instance method makes a "shallow" copy

copiedTable.append( row.copy() )

# return the copy

return copiedTable

if __name__ == "__main__":

boards:list = enumerateQueens3()

printTables( boards )