In Python, list comprehension is a concise way to create a newlistbased on the values of an existing list. List comprehension is often used for its brevity and readability compared to traditionalfor-loop. This Python tutorial discusses what is list comprehension, and its syntax with easy-to-un...
if yes, is y divisible by 5 or not. If y satisfies both conditions, the number appends to num_list. Example: List Comprehension with String We can also use list comprehension with iterables other than lists. word = "Python" vowels = "aeiou" # find vowel in the string "Python" resul...
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: ...
**其中的iterable表示可迭代的对象,包括字符串(str)、列表(list)、元组(tuple)、字典(dict)、集合(set),以及生成器(generator)等。 下面举例说明: 1.1.1 迭代对象为字符串str # 迭代对象为字符串str str_list = [x.lower() for x in 'Bruce_liuxiaowei'] str_list1 = [x.upper() for x in 'burce...
我们也可以用map加上lambda实现上述List Comprehension的功能: my_list = map(lambdaa: a*a, numbers) 上面三个代码段的功能类似,除了map函数返回的是iterator,但是从可读性来说,List Comprehension是最好的 (二)一些较为复杂的List Comprehension (1)加上if判断条件的List Comprehension: ...
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(11) 是从0开始，我们可以演示一下。print range(11)print range(1,11)print range(8,11)2 然后我们想一下 如果要表示[1*1,2*2,3*3,4*4...100*100]要怎么做呢?好...
list comprehension(列表推导式) 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"] ...
"Return the item if it is not banana, if it is banana return orange". Exercise? Consider the following code: fruits = ['apple', 'banana', 'cherry'] newlist = [x for x in fruits if x == 'banana'] What will be the value ofnewlist?
先看下比较常见的列表推导式 List Comprehension: 由于涉及到 key 和 value,字典的使用通常会复杂一下。 咱们先看下一个简单的字典推导式: 解释: key 是 num,取值从1到5; value 是 num**3,取值从1到125; 最后输出字典 回顾一下字典的遍历: 稍微复杂一点的字典推导式,只推导v,不推导k: 进一步的,在推导表...
What is list comprehension in Python? A concise syntax for creating a list from a range or an iterable object by applying a specified operation on each of its items. It performs much faster than its alternatives, such as for loops, lambda functions, conditionals, etc. When do we use list...