大神们 我不知道怎么写前面两个条件

Flashneilyoung

题目
Write a program that calculates the volume of a cylinder.

Your program will get the radius of the cylinder's base r and the height of the cylinder h as command line arguments. The radius will be given first.

Your program may encounter these unusual situations:

Program receives less than two arguments: print the message Not enough arguments.

Program receives more than two arguments: print the message Too many arguments.

Radius is negative: print the message Radius cannot be negative.

Height is negative (but radius is non-negative): print the message Height cannot be negative.

For all situations listed above, the program should terminate immediately after the message has been printed.

The value of pi should be set as a constant with the value 3.141592.

The volume of the cylinder should be printed to 2 decimal places, and can be calculated using the formula:

V=πr
2
h
Example 1:

$ python cylinder.py 4 10
The volume of the cylinder is 502.65.

---------------------------------
import sys
r = float(sys.argv[1])
h = float(sys.argv[2])
pi = 3.141592
value = pi * r**2 * h
if r <= 0:
        print('Radius cannot be negative.' )
elif h <= 0:
        print('Height cannot be negative.')       
else:       
        print('The volume of the cylinder is ' + '%0.2f'%value + '.')

Flashneilyoung

Program receives less than two arguments: print the message Not enough arguments.

Program receives more than two arguments: print the message Too many arguments.
就是这两个condition 不会 谢谢大佬们

无符号整形

1. len(sys.argv)

复制代码

Flashneilyoung

无符号整形 发表于 2018-8-15 21:52

import sys
r = float(sys.argv[1])
h = float(sys.argv[2])
pi = 3.141592
value = pi * r**2 * h
if (len(sys.argv)) > 3:
        print('Too many arguments.')
elif (len(sys.argv)) < 3:
        print('Not enough arguments.')
elif r <= 0:
        print('Radius cannot be negative.' )
elif h <= 0:
        print('Height cannot be negative.')       
else:
        print('The volume of the cylinder is ' + '%0.2f'%value + '.')


但是 Traceback (most recent call last):
-   File "cylinder.py", line 3, in <module>
-     h = float(sys.argv[2])
- IndexError: list index out of range
唯一实现不了就是print（‘not enough arguments')

无符号整形

Flashneilyoung 发表于 2018-8-16 18:56
import sys
r = float(sys.argv[1])
h = float(sys.argv[2])

先len(sys.argv)即可