[英]python convert a string to arguments list
Can I convert a string to arguments list in python? 我可以在python中将字符串转换为参数列表吗?
def func(**args):
for a in args:
print a, args[a]
func(a=2, b=3)
# I want the following work like above code
s='a=2, b=3'
func(s)
I know: 我知道:
list can, just use *list, but list can't have an element like: a=2 list can,只需使用* list,但list不能有如下元素:a = 2
and eval can only evaluate expression 和eval只能评估表达式
which would be like: 这将是:
def func2(*args):
for a in args:
print a
list1=[1,2,3]
func2(*list1)
func2(*eval('1,2,3'))
You could massage the input string into a dictionary and then call your function with that, eg 您可以将输入字符串按到字典中,然后用它调用您的函数,例如
>>> x='a=2, b=3'
>>> args = dict(e.split('=') for e in x.split(', '))
>>> f(**args)
a 2
b 3
You want a dictionary , not an 'argument list'. 你想要一个字典 ,而不是一个'参数列表'。 You also would be better off using ast.literal_eval()
to evaluate just Python literals: 你也将被关闭使用更好的ast.literal_eval()
来评估的 Python文字:
from ast import literal_eval
params = "{'a': 2, 'b': 3}"
func(**literal_eval(params))
Before you go this route, make sure you've explored other options for marshalling options first, such as argparse
for command-line options, or JSON for network or file-based transfer or persistence. 在开始这条路线之前,请确保首先探索了编组选项的其他选项,例如argparse
用于命令行选项,或JSON用于网络或基于文件的传输或持久性。
You can use the string as an argument list directly in an call to eval
, eg 您可以直接在eval
调用中将字符串用作参数列表,例如
def func(**args):
for a in args:
print( a, args[a])
s='a=2, b=3'
eval('func(' + s + ')')
>>>b 3
>>>a 2
note that func
needs to be in the namespace for the eval call to work like this. 请注意, func
需要在命名空间中才能使eval调用像这样工作。
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