python基础运用画彩虹，打印99乘法表，打印金字塔

#打印金字塔
ceng = eval(input("请输入要打印的层数"))

for x in range(ceng):
    for y in range(ceng-x):
        print("",end=' ')

    for z in range(x+1):
        print("*",end="")
    for l in range(x):
        print("*",end="")
    print("\n",end="")
``
```python
#输出9*9乘法表

for i in range(9):
    x = i + 1
    for y in range(i+1):
        l = y + 1
        print("%d*%d=%2d"%(x,l,x*l),end=" ")
    print("")

#画彩虹

import turtle
turtle.speed(10)
c = ['red','orange','yellow','green','Cyan','blue','Purple']
for i in range(7):
    y=6-i
    turtle.pencolor(c[y])
    turtle.pensize(20)
    turtle.penup()
    turtle.right(90)
    turtle.goto(-20*(i+1),0)
    turtle.down()
    turtle.circle(20*(i+1),-180)
    turtle.right(-(90+(180)))
turtle.done()