Welcome to the sixth installment of the How to Python series. Today, we’re going to learn how to clone or copy a list in Python. Unlike most articles in this series, there are actually quite a few options—some better than others. ...
mylist= thislist.copy() print(mylist) Try it Yourself » Use the list() method Another way to make a copy is to use the built-in methodlist(). Example Make a copy of a list with thelist()method: thislist = ["apple","banana","cherry"] ...
Understand how to copy lists in Python. Learn how to use the copy() and list() functions. Discover the difference between shallow and deep copies.
Let's say we have a List of Lists. If we make a copy with one of the above methods and change the inner elements, it still affects the other List as well: a=[[1,2],[3,4]]b=a[:]# or:# b = a.copy()# b = list(a)# b = copy.copy(a)b[0].append(99)print(b)# [...
Python列表(List) 序列是Python中最基本的数据结构。序列中的每个元素都分配一个数字 - 它的位置,或索引,第一个索引是0,第二个索引是1,依此类推。 Python有6个序列的内置类型,但最常见的是列表和元组。 序列都可以进行的操作包括索引,切片,加,乘,检查成员。
['z', 23]]在这里,变量list_of_lists,copy_lol指向了两个不同的对象,所以我们可以修改它们任何一个, 而不影响另外一个.然而,如果我们修改了一个对象中的元素,那么另一个也会受影响,因为它们中的元素还是共享引用. 如果你希望复制一个容器对象,以及它里面的所有元素(包含元素的子元素),使用copy.deepcopy,...
append(column) # nextCells is a list of column lists. while True: # Main program loop. print('\n\n\n\n\n') # Separate each step with newlines. currentCells = copy.deepcopy(nextCells) # Print currentCells on the screen: for y in range(HEIGHT): for x in range(WIDTH): print(...
s.copy(),本质上就相当于 s[:] python >>> list1 = ["Karene","and",19] >>> list2 = list1[:] >>> list1[1] = "or" >>> list1 ["Karene","or",19] >>> list2 ["Karene","and",19] s.clear() 只要出现,接下来的序列s就是空序列 python >>> list1 = ["Karene","pitay...
list.copy()Return a shallow copy of the list. Equivalent to a[:].返回一个列表的镜像，等效于a[:]。An example that uses most of the list methods:下面是这些方法的实例：>>> fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana']>>> fruits.count('apple')2 >...
(1)copy.copy(x) 浅拷贝其实就是用的切片操作 (2)完全切片法[:] (3)工厂函数,如list() 注意:浅拷贝中,对于不可变对象,拷贝后等于新创建对象,id值各不相同,也就是说对于非容器类型,没有拷贝一说;对于可变对象,拷贝仅相当于新增一个引用,id值不变,对一个变量进行修改会影响到其余变量。