for循环打印各种图形

for i in range(1,7): for j in range(1,i+1): print(j,end=' ') print()

for i in range(1,7): for j in range(1,8-i): print(j,end=' ') print()

for i in range(1,6):
for k in range(5-i, 0,-1):
print(' ',end=' ')
for j in range(i,0,-1):
print(j,end=' ')
print()