如何将字符串语句作为命令行参数传递

Question

以下代码采用可在 Python 端检索的单个字符串值。如何用带空格的句子字符串做到这一点？

from sys import argv

script, firstargument = argv

print "The script is called:", script
print "Your first variable is:", firstargument

要运行，我会这样传递参数：

$ python test.py firstargument

哪个会输出

The script is called:test.py
Your first variable is:firstargument

示例输入可以是“程序运行的 Hello world”，我想将其作为命令行参数传递，以存储在“first”变量中。

Answer 1

多字命令行参数，即包含多个由空格字符 %20 分隔的 ASCII 序列的单值参数，必须在命令行中用引号括起来。

$ python test.py "f i r s t a r g u m e n t"

The script is called:test.py
Your first variable is:f i r s t a r g u m e n t

这其实和Python完全没有关系，而是和your shell parses the command line arguments.的方式有关

Answer 2

argv 将是 shell 解析的所有参数的列表。

所以如果我做

#script.py
from sys import argv
print argv

$python script.py hello, how are you
['script.py','hello','how','are','you]

脚本的名称始终是列表中的第一个元素。如果我们不使用引号，每个单词也会成为列表的一个元素。

print argv[1]
print argv[2]
$python script.py hello how are you
hello
how

但如果我们使用引号，

$python script.py "hello, how are you"
 ['script.py','hello, how are you']

所有单词现在都是列表中的一项。所以做这样的事情

print "The script is called:", argv[0] #slicing our list for the first item
print "Your first variable is:", argv[1]

或者如果您出于某种原因不想使用引号：

print "The script is called:", argv[0] #slicing our list for the first item
print "Your first variable is:", " ".join(argv[1:]) #slicing the remaining part of our list and joining it as a string.

$python script.py hello, how are you
$The script is called: script.py
$Your first variable is: hello, how are you