对下面的程序有些疑问:
1)sys.argv 如果是代表在文件后的年数吗?如果是,那么应该:
if len ( sys.argv ) <2 #什么意思?:
    print "Usage:  leap.py year, year, year..."
    sys.exit ( 0 )

2) try :
	y = string.atoi ( i )
指什么意思?

3)    leap = "no"
 if y % 400 == 0 :
	leap = "yes"
    elif y % 100 == 0 :
	leap = "no"
    elif y % 4 == 0 :
	leap = "yes"
    else :
	leap = "no"
假设年份是 1904, leap应该为多少?


#!c:\python\python.exe
import sys
import string

if len ( sys.argv ) < 2 :
    print "Usage:  leap.py year, year, year..."
    sys.exit ( 0 )


for i in sys.argv[ 1 : ] :
    try :
	y = string.atoi ( i )
    except :
	print i, "is not a year."
	continue

    leap = "no"

    if y % 400 == 0 :
	leap = "yes"
    elif y % 100 == 0 :
	leap = "no"
    elif y % 4 == 0 :
	leap = "yes"
    else :
	leap = "no"

    print y, "leap:", leap, "in the Gregorian calendar"

    if y % 4 == 0 :
	leap = "yes"
    else :
	leap = "no"
    print y, "leap:", leap, "in the Julian calendar"

print "Calculated leapness for", len ( sys.argv ) - 1, "years"

1.
代表你传过去的参数
len ( sys.argv ) 取得参数数量

2.
没查文档，看名字猜测是ascii转整形

3.
%代表取余，答案应该知道了吧：）

在05-10-12，Shi Mu <samrobertsmith at gmail.com> 写道：
>
> 对下面的程序有些疑问:
> 1)sys.argv 如果是代表在文件后的年数吗?如果是,那么应该:
> if len ( sys.argv ) <2 #什么意思?:
> print "Usage: leap.py year, year, year..."
> sys.exit ( 0 )
>
> 2) try :
> y = string.atoi ( i )
> 指什么意思?
>
> 3) leap = "no"
> if y % 400 == 0 :
> leap = "yes"
> elif y % 100 == 0 :
> leap = "no"
> elif y % 4 == 0 :
> leap = "yes"
> else :
> leap = "no"
> 假设年份是 1904, leap应该为多少?
>
>
> #!c:\python\python.exe
> import sys
> import string
>
> if len ( sys.argv ) < 2 :
> print "Usage: leap.py year, year, year..."
> sys.exit ( 0 )
>
>
> for i in sys.argv[ 1 : ] :
> try :
> y = string.atoi ( i )
> except :
> print i, "is not a year."
> continue
>
> leap = "no"
>
> if y % 400 == 0 :
> leap = "yes"
> elif y % 100 == 0 :
> leap = "no"
> elif y % 4 == 0 :
> leap = "yes"
> else :
> leap = "no"
>
> print y, "leap:", leap, "in the Gregorian calendar"
>
> if y % 4 == 0 :
> leap = "yes"
> else :
> leap = "no"
> print y, "leap:", leap, "in the Julian calendar"
>
> print "Calculated leapness for", len ( sys.argv ) - 1, "years"
>
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> python-chinese at lists.python.cn
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>
>
>


--
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不能理解TRY, EXCEPT的用法,
能否指点一下?

用来捕获异常，try后面的是可能会出现异常的代码，except后面加异常类型和变 
量名称，如果，出现匹配的异常，就执行后面的代码。
这个可以查手册

Shi Mu wrote:
> 不能理解TRY, EXCEPT的用法,
> 能否指点一下?
>   
> ------------------------------------------------------------------------
>
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> python-chinese list
> python-chinese at lists.python.cn
> http://python.cn/mailman/listinfo/python-chinese
>