# 输出一行 * * * * * *
i = 0
while i<6:
print("*",end=" ")
i += 1
# 输出如下图形：
"""
* * * * * *
* * * * * *
* * * * * *
"""
i = 0
while i<6:
print("*",end=" ")
i += 1
print()
i = 0
while i<6:
print("*",end=" ")
i += 1
print()
i = 0
while i<6:
print("*",end=" ")
i += 1
print()
# 优化成使用while循环嵌套实现
j = 0
while j<3:
i = 0
while i<6:
print("*",end=" ")
i += 1
print()
j += 1
# 输出如下图形：
"""
* * * * * *
* * * * * *
* * * * * *
* * * * * *
* * * * * *
* * * * * *
"""
j = 0
while j<6:
i = 0
while i<6:
print("*",end=" ")
i += 1
print()
j += 1
