python vitality practice Day13

Day13: given an integer n, n lines obtained before Pascal's Triangle

. 1  DEF numRows (n):
 2      S1 = []    # Pascal's triangle before store n row number 
. 3      for I in Range (. 1, n +. 1 ):
 . 4          S = [. 1 for J in Range (I)]    # storage section the number i is set to the first row. 1 
. 5          IF len (S)> 2 :
 . 6              for i in Range (. 1, len (S) -1 ):
 . 7                  S [i] = S1 [-1] [. 1-i] S1 + [-1 ] [I]
 . 8              s1.append (S)
 . 9          the else :
 10              s1.append (S)
 . 11      return s1
12 
13 print(numrows(6))

Output: