解析Python文件并评估所选函数 [英] Parse Python file and evaluate selected functions

问题描述

我有一个文件，其中包含多个python函数，每个函数都有一些语句.

I have a file that contains several python functions, each with some statements.

def func1():
    codeX...
def func2():
    codeY...

codeX和codeY可以是多个语句.我希望能够解析该文件，按名称查找一个函数，然后评估该函数中的代码.

codeX and codeY can be multiple statements. I want to be able to parse the file, find a function by name, then evaluate the code in that function.

使用ast模块，我可以解析文件，找到FunctionDef对象，并获取Stmt对象的列表，但是如何将其转换为可以传递给eval的字节码?我应该使用编译模块还是解析器模块?

With the ast module, I can parse the file, find the FunctionDef objects, and get the list of Stmt objects, but how do I turn this into bytecode that I can pass to eval? Should I use the compile module, or the parser module instead?

基本上，函数defs仅用于创建单独的代码块.我希望能够获取给定名称的任何代码块，然后在eval中执行该代码(提供我自己的本地/全局范围对象).如果有比我描述的方法更好的方法，这也将有所帮助.

Basically, the function defs are just used to create separate blocks of code. I want to be able to grab any block of code given the name and then execute that code in eval (providing my own local/global scope objects). If there is a better way to do this than what I described that would be helpful too.

谢谢

推荐答案

使用Python 2.6.4:

Using Python 2.6.4:

text = """
def fun1():
    print 'fun1'

def fun2():
    print 'fun2'

"""

import ast
tree = ast.parse(text)
# tree.body[0] contains FunctionDef for fun1, tree.body[1] for fun2

wrapped = ast.Interactive(body=[a.body[1]])
code = compile(wrapped, 'yourfile', 'single')
eval(code)
fun2() # prints 'fun2'

看看ast doc中的语法: http://docs.python .org/library/ast.html#abstract-grammar .顶层语句必须是Module，Interactive或Expression，因此您需要在其中之一中包装def.

Take a look at grammar in ast doc: http://docs.python.org/library/ast.html#abstract-grammar. Top-level statement must be either Module, Interactive or Expression, so you need to wrap function def in one of those.

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