用Python计算面积的知识点：
1、 长方形面积和三角形面积，因为要从终端接收用户的多个参数输入，所以用了map(int, raw_input().split())这种方式
2. 圆面积只想保留小数点后两位，就用到了 %.2f
#!/usr/bin/python
#-*-coding:utf-8 -*-
name = raw_input("Please input your name here : ")
if name == '':
print("we don't like anonymous")
else:
choose = input("Which shape would you like to choose 1:Rectangle, 2:Square, 3:Triangle or 4 Round? :")
if choose == 1:
width, height = map(int, raw_input("Input width and height here, like 5 8 :").split())
print( "Area = %d" % (width * height))
elif choose == 2:
length = input("Input width and height here, like 4:")
print( "Area = %d" % length ** 2)
elif choose == 3:
width, height = map(int, raw_input("Input width and height here, like 5 8 :").split())
print( "Area = %d" % (width * height / 2))
elif choose == 4:
diameter = input("Input diameter here like 3 :")
print ("Area = %.2f" % (3.14 * (diameter / 2) ** 2))
else:
print( "Invalid choose")
