立即學習:https://edu.csdn.net/course/play/6861/334690?utm_source=blogtoedu
列表推導式(表達式)
[expression for i in iterable if condition]
list1 = [1,5,2,8,10,13,17,4,6]
[i**2 +1 for i in list1]
1、expression 就是對每一個元素的具體操作表達式
2、iterable 是某個可以迭代的對象,如列表、元組或者字符串
3、if condition 是對每一個元素做分支判斷,如果條件符合,則expression操作對應的元素
#3、統計列表中各元素的頻次,並且以字典的形式存儲統計結果,列表如下
#['A','C','A','C','B','C','A','A','B','C']
list = ['A','C','A','C','B','C','A','A','B','C']
dict = {}
for i in set(list):
dict[i] = list.count(i)
print(dict)
#3、統計列表中各元素的頻次,並且以字典的形式存儲統計結果,列表如下
#['A','C','A','C','B','C','A','A','B','C']
list = ['A','C','A','C','B','C','A','A','B','C']
dict = {}
for i in set(list):
dict[i] = list.count(i)
print(dict)
#2、將列表中的元素做平方減去5的操作,列表如下
#[10,2,16,11,18,21,25,17,22,19]
list1 = [10,2,16,11,18,21,25,17,22,19]
list2 = [i**2 -10 for i in list1]
print(list2)
#1、區分列表中所有包含e字母的單詞,列表如下
#['one','two','three','four','five','six','seven',"eight",'nine']
list = ['one','two','three','four','five','six','seven',"eight",'nine']
for i in list:
if i.find('e')!=-1:
print(i)