inspect.getsource returns unrelated code

The documentation of inspect.getsource states:

Return the text of the source code for an object. [...]

But the function returns slightly more code. It returns all lines of source code that overlap the object, even if the rest of the lines belong to different objects.

For example, the following code creates two lambdas in the same line, so inspect.getsource will return the code of both lambdas instead of just one.

import inspect

# Two function declarations in the same line
x = lambda: 1; y = lambda: 2

# prints "x = lambda: 1; y = lambda: 2\n"
print(repr(inspect.getsource(y)))

The returned code is not even necessarily valid Python, as the following list comprehension demonstrates:

import inspect

funcs = [
    lambda: 1 for
    _ in range(3)
]

# prints '    lambda: 1 for\n', including indentation and a stray "for"
print(repr(inspect.getsource(funcs[0])))

Background

I was trying to access the abstract syntax tree of a function (for JIT compilation), but that does not appear to be possible for lambdas.

Linked PRs

• gh-143301

从 inspect.getsource 开始，重现 issue 中的两个示例，然后检查周边实现以及现有的源代码提取测试。明确共享同一行或跨越推导式语法的 lambda 应有的行为，并添加回归测试覆盖，以展示应该返回什么。一个关联的 pull request gh-143301 表明相关工作已经转移到其他地方。