如何在 Python 中将整个列表作为命令行参数传递？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/32761999/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to pass an entire list as command line argument in Python?
提问by yogesh
I was trying to pass two lists containing integers as arguments to a python code. But sys.argv[i]gets the parameters as a list of string.
我试图将两个包含整数的列表作为参数传递给 python 代码。但是sys.argv[i]将参数作为字符串列表获取。
Input would look like,
输入看起来像，
$ python filename.py [2,3,4,5] [1,2,3,4]
I found the following hack to convert the list.
我发现以下技巧可以转换列表。
strA = sys.argv[1].replace('[', ' ').replace(']', ' ').replace(',', ' ').split()
strB = sys.argv[2].replace('[', ' ').replace(']', ' ').replace(',', ' ').split()
A = [float(i) for i in strA]
B = [float (i) for i in strB]
Is there a better way to do this?
有一个更好的方法吗？
采纳答案by Josh J
Command line arguments are always passed as strings. You will need to parse them into your required data type yourself.
命令行参数始终作为字符串传递。您需要自己将它们解析为所需的数据类型。
>>> input = "[2,3,4,5]"
>>> map(float, input.strip('[]').split(','))
[2.0, 3.0, 4.0, 5.0]
>>> A = map(float, input.strip('[]').split(','))
>>> print(A, type(A))
([2.0, 3.0, 4.0, 5.0], <type 'list'>)
Their are libraries like argparseand clickthat let you define your own argument type conversion but argparsetreats "[2,3,4]"the same as [2,3,4]so I doubt it will be useful.
它们是像argparse和click这样的库，可以让您定义自己的参数类型转换，但argparse处理方式"[2,3,4]"相同，[2,3,4]因此我怀疑它是否有用。
edit Jan 2019This answer seems to get a bit of action still so I'll add another option taken directly from the argparse docs.
编辑 2019 年 1 月这个答案似乎仍然有一些作用，所以我将添加另一个直接从 argparse 文档中获取的选项。
You can use action=appendto allow repeated arguments to be collected into a single list.
您可以使用action=append允许将重复的参数收集到一个列表中。
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('--foo', action='append')
>>> parser.parse_args('--foo 1 --foo 2'.split())
Namespace(foo=['1', '2'])
In this case you would pass --foo ?once for each list item. Using OPs example: python filename.py --foo 2 --foo 3 --foo 4 --foo 5would result in foo=[2,3,4,5]
在这种情况下，您将为--foo ?每个列表项传递一次。使用 OP 示例：python filename.py --foo 2 --foo 3 --foo 4 --foo 5将导致foo=[2,3,4,5]
回答by Ilya Peterov
No, there is no way pass a list in a command line argument. Command line arguments are always string. But there is a better way to convert it to list. You can do it like that:
不，无法在命令行参数中传递列表。命令行参数始终是字符串。但是有一种更好的方法可以将其转换为列表。你可以这样做：
import ast
A = ast.literal_eval(strA)
B = ast.literal_eval(strB)
回答by idjaw
I tested this on my end, and my input looks like this:
我对此进行了测试，我的输入如下所示：
python foo.py "[1,2,3,4]" "[5,6,7,8,9]"
I'm doing the following to convert the two params of interest:
我正在执行以下操作来转换感兴趣的两个参数：
import ast
import sys
list1 = ast.literal_eval(sys.argv[1])
list2 = ast.literal_eval(sys.argv[2])
回答by pregmatch
You have to escape:
你必须逃脱：
python some.py \[2,3,4,5\] \[1,2,3,4\]
some.py
一些.py
import sys
print sys.argv[1]
print sys.argv[2]
this gives me:
这给了我：
[2,3,4,5]
[1,2,3,4]
UPDATE:
更新：
import sys
import ast
d = ast.literal_eval(sys.argv[1])
b = ast.literal_eval(sys.argv[2])
for a in d:
print a
for e in b:
print e
first will give:
首先会给：
2
3
4
5
and second will give
第二个会给
1
2
3
4
回答by postelrich
Why not:
为什么不：
python foo.py 1,2,3,4 5,6,7,8
Much cleaner than trying to eval python and doesn't require your user to know python format.
比尝试 eval python 更干净，并且不需要您的用户知道 python 格式。
import sys
list1 = sys.argv[1].split(',')
list2 = [int(c) for c in sys.argv[2].split(',')] # if you want ints
回答by MisterMiyagi
Don't reinvent the wheel. Use the argparse module, be explicit and pass in actual lists of parameters
不要重新发明轮子。使用argparse 模块，明确并传入实际的参数列表
import argparse
# defined command line options
# this also generates --help and error handling
CLI=argparse.ArgumentParser()
CLI.add_argument(
"--lista", # name on the CLI - drop the `--` for positional/required parameters
nargs="*", # 0 or more values expected => creates a list
type=int,
default=[1, 2, 3], # default if nothing is provided
)
CLI.add_argument(
"--listb",
nargs="*",
type=float, # any type/callable can be used here
default=[],
)
# parse the command line
args = CLI.parse_args()
# access CLI options
print("lista: %r" % args.lista)
print("listb: %r" % args.listb)
You can then call it using
然后你可以调用它使用
$ python my_app.py --listb 5 6 7 8 --lista 1 2 3 4
lista: [1, 2, 3, 4]
listb: [5.0, 6.0, 7.0, 8.0]
回答by akazuko
You can also do the following:
您还可以执行以下操作：
say, you have foo.py:
说，你有foo.py：
import json
import sys
data = json.loads(sys.argv[1])
print data, type(data)
Then if you run the above as : python foo.py "[1,2,3]"
然后，如果您将上述内容运行为： python foo.py "[1,2,3]"
Output:
输出：
[1, 2, 3] <type 'list'>
[1, 2, 3] <type 'list'>
