解析字符串中函数的参数

Question

我只是一个代码的初学者，所以我不知道我是否在问一个愚蠢的问题，甚至可能会误用一些术语

我的问题是python中有一个字符串，其中包含一个可以理解为函数的文本，我想在列表中提取他的参数

字符串的示例：

line = """State("boatsmith search", "Search for the holder of the golden compass", delay=6)"""

作为处理该字符串的结果，我希望：

["boatsmith search", "Search for the holder of the golden compass", "delay=6"]

我不知道我说的是否清楚

我要找的东西是：

line = """State("boatsmith search", "Search for the holder of the golden compass", delay=6)"""

def function(x)
    # magic with x
    return list() # a list type result not actualy a list() xD

function(line)

>> ["boatsmith search", "Search for the holder of the golden compass", "delay=6)"]

事先非常感谢

Answer 1

您可以在下面尝试：

line = """State("boatsmith search", "Search for the holder of the golden compass", delay=6)"""

def function(x)
    start = x.find("(") + len("(")
    end = x.find(")")
    substring = x[start:end]
    print(substring.replace('"', '').split(','))

Answer 2

您可以使用ast模块解决此问题。它有ast.NodeVisitor，这是一个基类，它遍历抽象语法树，并为找到的每个节点调用访问者函数

>>> line = """State("boatsmith search", "Search for the holder of the golden compass", delay=6)"""
>>> import ast
>>> tree = ast.parse(line)
>>> args = []
>>>
>>> class VisitCall(ast.NodeVisitor):
...     def visit_Call(self, node):
...         for i in node.args + node.keywords:
...             if isinstance(i, ast.Constant):
...                 args.append(i.value)
...             if isinstance(i, ast.keyword):
...                 args.append(f"{i.arg}={i.value.value}")
...
>>> visitor = VisitCall()
>>> visitor.visit(tree)
>>> print(args)
['boatsmith search', 'Search for the holder of the golden compass', 'delay=6']

您可以在visit_Call方法中处理不同的条件

Answer 3

可以使用正则表达式：

import re

re.search('\((.*)\)', line.replace('"', '')).group(1).split(', ')

输出：

['boatsmith search', 'Search for the holder of the golden compass', 'delay=6']

---

the string could be written with double quotes or with single quotes

在这种情况下，您可以使用：

line = """State("boatsmith search", 'Search for the holder of the golden compass', delay=6)"""

[e.strip('"\'') for e in re.search('\((.*)\)', line).group(1).split(', ')]

输出：

['boatsmith search', 'Search for the holder of the golden compass', 'delay=6']