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...
The list comprehension uses the tuplefish_tupleas the basis for the new list calledfish_list. The keywords offorandinare used, as they were in thesection above, and now anifstatement is added. Theifstatement says to only add those items that are not equivalent to the string'octopus', so...
When the size of a list becomes problematic, it’s often helpful to use a generator instead of a list comprehension in Python. A generator doesn’t create a single, large data structure in memory, but instead returns an iterable. Your code can ask for the next value from the iterable as...
In this Python Tutorial we will be learning about Lists Comprehension in Python. List comprehension provides a simple and concise way to create lists.
我们在上一章学习了“Lambda 操作, Filter, Reduce 和 Map”, 但相对于map, filter, reduce 和lamdba, Guido van Rossum更喜欢用递推式构造列表(List comprehension)。在这一章我们将会涵盖递推式构造列表(List comprehension)的基础功能。 递推式构造列表(List comprehension)是在Python 2.0中添加进来的。本质上,...
(一)使用List Comprehension的好处 在了解Python的List Comprehension之前,我们习惯使用for循环创建列表,比如下面的例子: numbers = range(10) my_list=[]fornumberinnumbers: my_list.append(number*number)print(my_list) 可是在Python中,我们有更简洁,可读性更好的方式创建列表,就是List Comprehension: ...
Also see thecomprehensiondefinitioninPython Terminology. What does a list comprehension look like? We have a list of strings (screencasts) that Python Morsels represents screencast names: >>>screencasts=[..."Data structures contain pointers",..."What is self?",..."What is a class?",..."...
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: ...
The program output: [ (1,3),(1,2), (2,3),(2,1), (3,2),(3,1)] Due to a tendency to quickly become unreadable,using list comprehensions within list comprehensions is not advisable. 4. Conclusion List comprehension in Python provides an efficient way to create new lists without using...
List comprehension in Python provides a concise way to create lists. It allows generating a new list by applying an expression to each element in an iterable, such as a list, tuple, or range, in a single line of code. This method improves readability and performance compared to traditional ...