python的inspect模塊正如他們的命名一樣，是用于檢查運行模塊的一些基本信息，有了inspect模塊，我們可以做很多有意思的事情，下面主要想探究一下inspect模塊

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)獲取所有的attr-key
for key in dir(object):
    try:
        value = getattr(object, key)
    except AttributeError:
        continue
    # 如果有預測函數則進行預測
    if not predicate or predicate(value):
        results.append((key, value))
results.sort()
return results

getmembers方法的實現非常簡單，其內部的實現就是用內建函數dir實現的。

inspect.currentframe

currentframe內部實現是通過sys._getframe實現的。在使用currentframe的時候要注意防止循環引用。

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

inspect的使用

1. 獲取調用函數的實例

# 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