从Python2.4开始,list.sort()和sorted()方法都添加了一个key参数来说明一个函数,这个函数在做比较之前会对list中的每个元素进行调用。 例如,这里是一个大小写不敏感的字符串比较: >>> sorted("This is a test string from Andrew".split(), key=str.lower) ['a', 'Andrew', 'from', 'is', 'string'...
>>>s=sorted(student_objects,key=attrgetter('age'))# sort on secondary key>>>sorted(s,key=attrgetter('grade'),reverse=True)# now sort on primary key, descending[('dave','B',10),('jane','B',12),('john','A',15)] 1. 2. 3. 6. 其他语言普遍使用的排序方法-cmp函数 在python2.4...
>>>s=sorted(student_objects,key=attrgetter('age'))# sort on secondary key>>>sorted(s,key=attrgetter('grade'),reverse=True)# now sort on primary key, descending[('dave','B',10),('jane','B',12),('john','A',15)] 6)最老土的排序方法-DSU 我们称其为DSU(Decorate-Sort-Undecorate),...
>>> s = sorted(student_objects, key=attrgetter('age')) # sort on secondary key >>> sorted(s, key=attrgetter('grade'), reverse=True) # now sort on primary key, descending [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)] 1. 2. 3. 4.新增的问题: 今天遇...
>>> s = sorted(student_objects, key=attrgetter('age'))#sort on secondary key>>> sorted(s, key=attrgetter('grade'), reverse=True)#now sort on primary key, descending[('dave','B', 10), ('jane','B', 12), ('john','A', 15)] ...
secondary_sorted = sorted(top_grouped, key=policy.secondary_sorting_criteria, reverse=True) candidates = itertools.takewhile(policy.selection_criteria, secondary_sorted) return list(candidates)[:policy.desired_number_of_recommendations] # dummy functions to get code to run ...
7. 更复杂排序 更复杂地你可以构建多个步骤来进行更复杂的排序,例如对student数据先以age升序排列,再以grade降序排列。 >>>s=sorted(student_objects,key=attrgetter('age'))# sort on secondary key>>>sorted(s,key=attrgetter('grade')
>>>s=sorted(student_objects,key=attrgetter('age'))# sort on secondary key>>>sorted(s,key=attrgetter('grade'),reverse=True)# now sort on primary key,descending[('dave','B',10),('jane','B',12),('john','A',15)] 传统的DSU(Decorate-Sort-Undecorate)的排序方法 ...
sorted() 函数对所有可迭代的对象进行排序操作 语法如下: sorted(iterable, cmp=None, key=None, reverse=False) 参数说明: iterable – 可迭代对象。 cmp – 比较的函数,这个具有两个参数,参数的值都是从可迭代对象中取出,此函数必须遵守的规则为,大于则返回1,小于则返回-1,等于则返回0。(一般省略) ...
>>> s =sorted(student_objects, key=attrgetter('age'))# sort on secondary key>>>sorted(s, key=attrgetter('grade'), reverse=True)# now sort on primary key, descending[('dave','B',10), ('jane','B',12), ('john','A',15)] ...