菱形
n=6
for i in range(n):
for j in range(n-i-1):
print(" ",end="")
for k in range(2*i+1):
print("*",end="")
print("")
for i in range(n-1):
for j in range(i+1):
print(" ",end="")
for k in range(2*(n-i)-3):
print("*",end="")
print("")