Python Inspect Module小结

python的inspect模块正如他们的命名一样，是用于检查运行模块的一些基本信息，有了inspect模块，我们可以做很多有意思的事情，下面主要想探究一下inspect模块

inspect.getmembers

def getmembers(object, predicate=None):
"""Return all members of an object as (name, value) pairs sorted by name.
Optionally, only return members that satisfy a given predicate."""
results = []
# 使用dir(builtin)获取所有的attr-key
for key in dir(object):
    try:
        value = getattr(object, key)
    except AttributeError:
        continue
    # 如果有预测函数则进行预测
    if not predicate or predicate(value):
        results.append((key, value))
results.sort()
return results

getmembers方法的实现非常简单，其内部的实现就是用内建函数dir实现的。

inspect.currentframe

currentframe内部实现是通过sys._getframe实现的。在使用currentframe的时候要注意防止循环引用。

def handle_stackframe_without_leak():
    frame = inspect.currentframe()
try:
    # do something with the frame
finally:
    del frame

inspect的使用

1. 获取调用函数的实例

# file: util.py
def get_caller():
    import inspect
    try:
        frame = inspect.currentframe()
        call_frame = frame.f_back.f_back
        call_frame_name = call_frame.f_code.co_varnames[0]
        call_frame_self = call_frame.f_locals.get(call_frame_name, None)
    except:
        call_frame_self = None
    finally:
        del frame
    return call_frame_self