在Python中,我们可以使用列表推导式(list comprehension)来展开多个子列表。下面是一个简单的示例: nested_list=[[1,2],[3,4],[5,6]]flattened_list=[itemforsublistinnested_listforiteminsublist]print(flattened_list) 1. 2. 3. 在这个示例中,我们首先定义了一个嵌套列表nested_list,然后使用列表推导式将...
Nested List Comprehensions >>> matrix = [ ... [1, 2, 3, 4], ... [5, 6, 7, 8], ... [9, 10, 11, 12], ... ] The following list comprehension will transpose rows and columns: >>> [[row[i] for row in matrix] for i in range(4)] [[1, 5, 9], [2, 6, 10],...
This Python tutorial discusses what is list comprehension, and its syntax with easy-to-understand examples, usingif-elsestyle conditions in comprehensions and writing nested list comprehensions involving two lists. Quick Reference # A new list of even numbers from existing list containing numbers 0-9...
Python 列表:基础知识与应用场景 1.列表(List)的概念 列表是 Python 中最常用的数据结构之一,用于存储一组有序的元素。可以存储不同类型的数据,甚至可以存储其他列表(嵌套列表)。列表是可变类型,可以随时修改、添加或删除元素。 2.创建列表 空列表: empty_list = [] 包含元素的列表: fruits = ['apple','banan...
Here, we create a nested list calledmatrixusing nested list comprehension: [j for j in range(1, 4)]: Generates a list containing numbers 1 to 3. for i in range(3): Repeats this process 3 times to create 3 rows. Output: Matrix: [[1, 2, 3], [1, 2, 3], [1, 2, 3]] ...
Python nested list comprehensions The initial expression in a Python list comprehension can be another list comprehension. nested_list_comprehension.py #!/usr/bin/python M1 = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] M1_tr = [[row[i] for row in M1] for i in range(3)] ...
Createlistcomprehension: squares squares = [i**2foriinrange(0,10)] nested list comprehensions [[output expression]foriterator variableiniterable] writing a list comprehension within another list comprehension, or nested list comprehensions. # Create a 5 x 5 matrix using a list of lists: matrixma...
# Python 3 code to demonstrate # removing duplicated from list # using list comprehension + enumerate() # initializing listtest_list = [1, 5, 3, 6, 3, 5, 6, 1]print ("The original list is : " + str(test_list)) # using list ...
Learn how to effectively use list comprehension in Python to create lists, to replace (nested) for loops and the map(), filter() and reduce() functions, ...!
列表推导式另一个优点是相比于for循环更高效,因为列表推导式在执行时调用的是Python的底层C代码,而for循环则是用Python代码来执行。比如我们需要创建一个包含平方数的列表,用for循环实现方式如下: squares = [] for i in range(10): squares.append(i**2) print(squares) 如果用列表推导式的话只需一行代码...