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...
(说明一下,第一个for loop里面的if从句是多余的,len(seq)一直不变。 参考:http://stackoverflow.com/questions/7847624/list-comprehension-for-loops-python http://rhodesmill.org/brandon/2009/nested-comprehensions/ http://www.python-course.eu/list_comprehension.php...
# create a new list using list comprehensionsquare_numbers = [num * numfornuminnumbers] print(square_numbers)# Output: [1, 4, 9, 16, 25] Run Code It's much easier to understand list comprehension once you knowPython for loop(). Conditionals in List Comprehension List comprehensions can ...
【Python学习】- List comprehension A list comprehension allows you to generate this same list in just one line of code. 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 ra...
2)把东西塞到list里, [iforiinrange(1, 101)] 3)把list return回来 return [iforiinrange(1, 101)] 没错这样你就通过list comprehension构成了一个1到100所有数字的list FOR LOOP with CONDITION 又是一枚栗子 如果我们想要create一个list让它里面每一个元素是1-100所有奇数的平方的话会怎么做?
首先肯定 map 和列表推导效率确实会比循环的高，先说列表推导，下边是我在ipython里的测试结果（测试环境...
1. 列表推导与循环在效率上的比较确实存在差异。在 Python 2.7.10 的测试中，列表推导的速度通常快于 for 循环。2. 列表推导之所以效率较高，关键在于其字节码直接使用了‘LIST_APPEND’指令来添加元素，而 for 循环则需要先调用 append 方法，这个过程耗费更多时间。3. 通过将 append 函数存入局部...
1.List Comprehension / Generator 表达式 我们来看一个简单的例子。如果你想将一个数组转换为另一个数组: result = []for item in item_list:new_item = do_something_with(item)result.append(item) 如果你喜欢 MapReduce,你也可以使用 map,或者 Python 中的 List Comprehension: ...
List comprehensions in Python 02:24 Turning a for loop into a list comprehension 04:28 Why use a list comprehension? 02:31 Set and dictionary comprehensions 03:19 When should you not use a list comprehension? 03:14 Using "else" in a comprehension ...
Introduction to Python List Comprehension List comprehensions in Python provide a concise way to create lists. They are not only more readable but also more efficient than traditional for-loops. This tutorial focuses on practical examples to help you master list comprehensions with minimal theory. ...