python获取从命令行输入数字的方法

#----------------------------------------
# Name: numerical_input.py
# Author: Kevin Harris
# Last Modified: 02/13/04
# Description: This Python script demonstrates 
# how to get numerical input
# from the command line 
# and use the if-else conditional.
#----------------------------------------
print()
print( "Welcome to the Area calculation program" )
print( "---------------------------------------" )
print()
# Print out the menu:
print( "Please select a shape:" )
print( "1 Rectangle" )
print( "2 Circle" )
print()
# The input function both prompts the user
# for input and fetches it...
shape = int( input( "> " ) )
# Calculate the area...
if shape == 1:
 height = int( input("Please enter the height: ") )
 width = int( input("Please enter the width: ") )
 area = height*width
 print( "The area is", area )
else:
 radius = int( input("Please enter the radius: ") )
 area = 3.14*(radius**2)
 print( "The area is", area )
input( '

Press Enter to exit...' )