print(d1['name'])#当 key 不存在时,会报错:KeyErrorprint(d1.get('money'))#当 key 不存在时,不会报错,返回一个 Noneprint(d1.get('money',0))#当 key 不存在,返回默认值为 0print(d1.keys())#取到字典里面所有的key,存为一个 listprint(d1.values())#取到字典里面所有的value,存为一个 ...
'chemistry', 1997, 2000];dellist1[1]#删除指定索引上面的元素dellist1[2:3]#删除列表元素(下标,默认删除最后一个且获取删除值)list1.pop();#默认删除最后一个元素name=list1.pop(1)#删除下标1上的元素,且获取删除值#删除列表元素(元素名称)list1.remoe('physics')...
<1>find 检测str 是否包含在 mystr中,如果是返回开始的索引值,否则返回-1 <2>index 跟find()方法一样,只不过如果str不在 mystr中会报一个异常. <3>count 返回str在start和end之间 在 mystr里面出现的次数 <4>replace 把mystr 中的 str1 替换成 str2,如果 count 指定,则替换不超过 count 次. <5>s...
s=list(input().split(',')) a=set(s) b=list(a) b.sort(key=s.index) print(b) 猜年龄 描述 美国数学家维纳(N.Wiener)智力早熟,11岁就上了大学。他曾在1935~1936年应邀来中国清华大学讲学。一次,他参加某个重要会议,年轻的脸孔引人注目。于是有人询问他的年龄,他回答说:“我年龄的立方是个4位数。
1 Python - finding value position in a list and outputting as a new list 2 Getting the position of an item in a list from an input (Python) 0 When given a position of an item in a list, how do I print that value? 5 Find first position of values in list 0 How to ...
Return Value from List index() The index() method returns the index of the given element in the list. If the element is not found, a ValueError exception is raised. Note: The index() method only returns the first occurrence of the matching element. Example 1: Find the index of the ele...
max_value, max_index =max((x, (i, j))fori, rowinenumerate(my_list)forj, xinenumerate(row)) but I don't understand how to adapt it for a 3rd list. Another question: Is there an easy way to apply the following operation on all the elements of my list ?
Python 中,可以使用 dict 字典类型提供的 fromkeys 函数创建带有默认值的字典,语法格式为:dictname = dict.fromkeys(list,value=None),其中,list 参数表示字典中所有键的列表(list),value 参数表示默认值,如果不写,则为空值 None。 list1 = ["语文", "数学", "英语"] dict1 = dict.fromkeys(list1) print...
There should be one-- and preferably only one --obvious way to do it. Although that way may not be obvious at first unless you're Dutch. Now is better than never. Although never is often better than *right* now. If the implementation is hard to explain, it's a bad idea. ...
列表和字典是python内置的两种非常常见的数据结构，可以将它们理解为一个数据容器，其主要用途都是用于存放...