这是因为深度拷贝函数 deepcopy 中会维护一个字典,记录已经拷贝的对象与其 ID。拷贝过程中,如果字典里已经存储了将要拷贝的对象,则会从字典直接返回。 defdeepcopy(x, memo=None, _nil=[]):"""Deep copy operation on arbitrary Python objects. See the module's __doc__ string for more info. """ifme...
二、浅拷贝(shallow copy): 浅拷贝会创建新对象,其内容非原对象本身的引用,而是原对象内第一层对象的引用。浅拷贝有三种形式:切片操作、工厂函数、copy 模块中的 copy 函数。 三、深拷贝(deep copy): 深拷贝只有一种形式,copy 模块中的 deepcopy()函数。深拷贝和浅拷贝对应,深拷贝拷贝了对象的所有元素,包括多...
copy --- 浅层 (shallow) 和深层 (deep) 复制操作 首先定义了一个Bus类;self.passenger属性为列表,用于存储数据;pick方法是上车人员;drop方法是下车人员 class Bus: def __init__(self, passenger=None): if passenger is None: self.passenger = [] else: self.passenger = list(passenger) def pick(sel...
/usr/bin/python# -*-coding:utf-8 -*-importcopya=[1,2,3,4,['a','b']]#原始对象b=a#赋值,传对象的引用c=copy.copy(a)#对象拷贝,浅拷贝d=copy.deepcopy(a)#对象拷贝,深拷贝a.append(5)#修改对象aa[4].append('c')#修改对象a中的['a', 'b']数组对象print('a =',a)print('b ='...
Usecopy.copy()to clone a List¶ importcopyb=copy.copy(a) Shallow vs. Deep copying¶ All the above mentioned ways do not produce side effects for 1 level deep Lists: a=[ 1,2,3]b=a[:]# or:# b = a.copy()# b = list(a)# b = copy.copy(a)b.append(4)print(b)# [1,...
Understand how to copy lists in Python. Learn how to use the copy() and list() functions. Discover the difference between shallow and deep copies.
copy修改: 赋值:mylist = mylist + [1,2] slicing 5. numpy: 我辛辛苦苦总结了numpy所有修改操作可能涉及到view和copy的类型,一表胜千言。 view:slicing, view, ravel,augmented assignment 他们reference id不一样,但是改变值本身,原本对应的数据也会改变 ...
2. Deep Copy of List Write a Python program to create a deep copy of a given list. Use copy.copy Click me to see the sample solution 3. Shallow Copy of Dictionary Write a Python program to create a shallow copy of a given dictionary. Use copy.copy ...
copy — Shallow and deep copy operations — Python 3.8.2rc1 documentation https://docs.python.org/3.8/library/copy.html Assignment statements in Python do not copy objects, they create bindings between a target and an object. AI检测代码解析 ...
>>> mylist[1]=2 >>> mytuple=(1,3,3) >>> mytuple[1]=2 Traceback (most recent calllast): File"<pyshell#97>", line 1,in<module> mytuple[1]=2 1. 2. 3. 4. 5. 6. 7. 会出现以下报错: 复制 TypeError: ‘tuple’ object doesnotsupport item assignment ...