python --- formula

1、[(x,y) for x in [1,2,3] for y in [4,2,3] if x == y]

　　(X, y): output expression, generating a final list of elements

　　X for in [ . 1, 2, . 3] for Y in [ . 4, 2, . 3]: input list

　　X == IF Y : Analyzing expression optional

m = [(x,y) for x in [1,2,3] for y in [4,2,3] if x == y]
print(m)
Console Output: [( 2 , 2 ), ( 3 , 3 )]