Double list comprehension, or nested list comprehension, involves one list comprehension within another. This technique is useful for processing and creating multi-dimensional lists or matrices. Be cautious because the double list comprehension works like a nested for loop so it quickly generates a lot...
最近在做hangman小游戏(12 Beginner Python Projects - Coding Course)发现有一行用了list comprehension搞的不是很懂: word_list=[letterifletterinused_letterselse'-'forletterinword] 经过学习后发现这一行是用了更简洁的list comprehension来写,用for loop来写的话是这样: word_list=[]forletterinword:iflette...
# Function to double a numberdefdouble(num):returnnum*2# Using list comprehension with a functiondoubled_numbers=[double(x)forxinrange(1,6)]# Printing the resultprint("Doubled numbers:",doubled_numbers) Here, we define a functiondouble(num)that returns twice the input value: double(num)...
很多时候我们需要创建一个满足特定要求的新列表,不得不用for循环来创建,而用列表推导式来表达只需要一行代码即可。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: ...
如果想了解list comprehension原理的东西,这个人文章写得很清楚:http://blog.chinaunix.net/uid-28631822-id-3488324.html 5.实践: 在来一道题,摘自《Python基础教程》: >>> girls = ['alice','bernice','clarice']>>> boys = ['chris','arnold','bob']>>> [b+'+'+gforbinboysforgingirlsifb[0]=...
A list comprehension combines the for loop and the creation of new elements into one line, and automatically appends each new element. squares = [value**2 for value in range(1, 11)] print(squares) To use this syntax, begin with a descriptive name for the list, such as squares. Next ...
Suppose we have a list of numbers and we desire to create a new list containing the double value of each element in the list. numbers = [1, 2, 3, 4] # list comprehension to create new list doubled_numbers = [num * 2 for num in numbers] print(doubled_numbers) Run Code Output...
在python中,list comprehension(或译为列表推导式)可以很容易的从一个列表生成另外一个列表,从而完成诸如map, filter等的动作,比如: 要把一个字符串数组中的每个字符串都变成大写: names = ["john", "jack", "sean"] result = [] for name in names: ...
今天我们复习一下之前的课程-列表！然后从新给大家介绍一个新的概念，列表生成式即List Comprehension，是一个简单而又强大的内置功能之一。工具/原料 python2.7 pycharm 编辑工具 方法/步骤 1 举个例子如果我们要生产一个list [1,2,3,4,5,6,7,8,9,10] 我们可以使用range(1,11)来表示，如果直接写range(...
forxinfruits: if"a"inx: newlist.append(x) print(newlist) Try it Yourself » With list comprehension you can do all that with only one line of code: Example fruits = ["apple","banana","cherry","kiwi","mango"] newlist = [xforxinfruitsif"a"inx] ...