Question

例如，

我想从。

创建一个函数对象

mystr = \
"""
def foo(a=1): 
    print a
    pass
"""

但是，使用compile（mystr）只会给我一个代码对象。我想拥有模块级函数对象，就像字符串是源代码的一部分一样。

这可以实现吗？

Answer 1

exec mystr

将执行您提供的代码。

Answer 2

是使用exec：

>>> mystr = \
"""
def foo(a=1): 
    print a
    pass
"""
>>> exec mystr
>>> foo
<function foo at 0x0274F0F0>

Answer 3

您也可以在此使用compile，它支持exec，eval，single等模式：

In [1]: mystr = \
"""
def foo(a=1): 
        print a
        pass
"""
   ...: 

In [2]: c=compile(mystr,"",'single')

In [3]: exec c

In [4]: foo
Out[4]: <function __main__.foo>

compile上的帮助：

In [5]: compile?
Type:       builtin_function_or_method
String Form:<built-in function compile>
Namespace:  Python builtin
Docstring:
compile(source, filename, mode[, flags[, dont_inherit]]) -> code object

Compile the source string (a Python module, statement or expression)
into a code object that can be executed by the exec statement or eval().
The filename will be used for run-time error messages.
The mode must be 'exec' to compile a module, 'single' to compile a
single (interactive) statement, or 'eval' to compile an expression.
The flags argument, if present, controls which future statements influence
the compilation of the code.
The dont_inherit argument, if non-zero, stops the compilation inheriting
the effects of any future statements in effect in the code calling
compile; if absent or zero these statements do influence the compilation,
in addition to any features explicitly specified.

我可以从字符串动态创建模块级函数对象吗？

3 个答案: