有2道PYTHON题求解答

Question

题目一
Exercise 3.9
Test if the t value read in the program from Exercise 3.7 lies between 0 and 2*v0/g. if not, print a massage and abort execution.Name of program file:ball_cml_errorcheck.py
3.7的题目如下
Modify the program listed in exercise such that v0 and t are read from the command line. （v0=3，t=0.6）
然后3.7的题目解答如下
import sys
v0=float(sys.argv[1])
t=float(sys.argv[2])
g=9.81
y=v0*t-0.5*g*t**2
print y

= =想问下3.9这道题怎么做……咱还是新手刚学~想请教下
知道开头是这样
import sys
try:什么什么什么
except：什么什么什么

还有一道额……
Exercise 3.10
Instead of printing an error message and aborting the program explicitly,raise a valueerror exception in the if test on legal t values in the program from Exercise 3.9.The exception message should contain the legal interval for t.

谁能解答下~谢了哈
答案满意者+悬赏

Answer 1

import sys
try:
v0=float(sys.argv[1])
t=float(sys.argv[2])
g=9.81
if t<0 or t>2*v0/g:
raise
y=v0*t-0.5*g*t**2
print y
except:
print "t invalid"

import sys
try:
v0=float(sys.argv[1])
t=float(sys.argv[2])
g=9.81
s=2*v0/g
if t<0 or t>s:
raise
y=v0*t-0.5*g*t**2
print y
except:
raise ValueError,"t shold be in%s"%repr([0,s])