Question

以下是Zed A. Shaw的“学习蟒蛇的艰难方式”的片段。当我将第一个或第二个变量初始化为argv时，我收到错误。我还没有找到解释。

from sys import argv
script, first, second, third=argv

print "the script is called:",script
print "your first variable is called ",first
print "your second variable is called ",second
print "your third variable is called ",third

Answer 1

我可以复制错误以查看发生了什么错误吗？

当我执行上面的代码时，它会正常运行。

不使用COMMA

Argv检查空间。

$ python b.py 1 2 3  
the script is called: b.py
your first variable is called  1
your second variable is called  2
your third variable is called  3

<强>版本

 ⚡ root@dev # uname -a 
Linux dev 4.4.0-1031-aws #40-Ubuntu SMP Thu Aug 10 11:29:58 UTC 2017 x86_64 
x86_64 x86_64 GNU/Linux
⚡ root@dev # cat /etc/issue
Ubuntu 16.04.2 LTS \n \l
⚡ root@dev # python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)

Answer 2

您没有初始化第三个参数。你正在拆包argv。 a,b,c = argv就像a = argv[0]; b = argv[1]; c = argv[2];...

Answer 3

如果要在参数之间使用逗号，则始终需要提供一个空格，否则编译器会认为def is_palindrome(seq): n = len(seq) m = n // 2 q = m + n % 2 - 1 return seq[:m] == seq[:q:-1] print(is_palindrome('ciao')) # False print(is_palindrome('aboba')) # True print(is_palindrome('abooba')) # True是一个参数，因此会出现错误：

1,2,3

像这样调用脚本：

ValueError: need more than 2 values to unpack

如果我将argv初始化为除第三个以外的任何其他变量，我会收到错误

3 个答案: