摘要: The slice operator can take a third argument that determines the step size, so t[::2] creates a list that contains every other element from t. If the ... 阅读全文
posted @ 2014-07-13 19:55 平静缓和用胸音说爱 阅读(193) 评论(0) 推荐(0) 编辑
摘要: A string is a sequence of characters and a list is a sequence of values, but a list of characters is not the same as a string. To convert from a strin... 阅读全文
posted @ 2014-07-13 19:20 平静缓和用胸音说爱 阅读(218) 评论(0) 推荐(0) 编辑
摘要: When you assign an object to a variable, Python copies the reference to the object. In this case a and b refer to the same list.If you want ... 阅读全文
posted @ 2014-07-13 18:59 平静缓和用胸音说爱 阅读(172) 评论(0) 推荐(0) 编辑
摘要: If we execute these assignment statements: We know that a and b both refer to a string, but we don’t know whether they refer to the same str... 阅读全文
posted @ 2014-07-13 18:41 平静缓和用胸音说爱 阅读(254) 评论(0) 推荐(0) 编辑
摘要: There are several ways to delete elements from a list. If you know the index of the element you want, you can use pop: pop modifies the list... 阅读全文
posted @ 2014-07-13 17:21 平静缓和用胸音说爱 阅读(173) 评论(0) 推荐(0) 编辑
摘要: To add up all the numbers in a list, you can use a loop like this: Total is initialized to 0. Each time through the loop, x gets one element... 阅读全文
posted @ 2014-07-13 16:59 平静缓和用胸音说爱 阅读(302) 评论(0) 推荐(0) 编辑
摘要: Python provides methods that operate on lists. For example, append adds a new element to the end of a list, extend takes a list as an argument and app... 阅读全文
posted @ 2014-07-13 15:06 平静缓和用胸音说爱 阅读(209) 评论(0) 推荐(0) 编辑
摘要: The + operator concatenates lists: Similarly, the * operator repeats a list a given number of items:List slicesThe slice operator also works... 阅读全文
posted @ 2014-07-13 14:51 平静缓和用胸音说爱 阅读(281) 评论(0) 推荐(0) 编辑
摘要: The most common way to traverse the elements of a list is with a for loop. The syntax is the same as for strings: This works well if you onl... 阅读全文
posted @ 2014-07-13 14:38 平静缓和用胸音说爱 阅读(221) 评论(0) 推荐(0) 编辑