【Python】字典或者對象類型中鍵或者屬性的獲取與存在性判斷

# 定義測試用對象A，字典B class A(object): length = 10 B ={"length":10} # 判斷對象是否含有某種屬性 # 推薦這種方式,更Pythonic try: x = A.lengt except AttributeError: print("does not have {}".format("lengt")) # 這種low一點 if "leng" in dir(A): print(A.length) else: print("does not have {}") # 或者這種方式 try: x = getattr(A,"length") except AttributeError: print("does not have {}".format("lengt")) # 判斷字典是否具有某個鍵： try: x = B['ssss'] except KeyError: print("Not have") # 或者 if x in x.keys(): do something # 或者 if x.get('gridman'): do something else print("Not have") # 獲取屬性的方式 # 對象 print(getattr(A,"length")) print(A.length) print(B.get("length","if not have return DefaultValue")) print(B['length']) # 注意 從**kwargs中獲取參數值可以等同於從字典中獲取的方式