Python 中对数据进行排序是非常简单的,其内置了列表 list 的排序方法 sort,同时还内置了 sorted 方法,不仅可以对 list 排序,还可以对 tuple 和dict 排序。不仅如此,关于排序 Python 还提供其它的选择,以应对更多的场景,如:heapq、collection.Counter。 sort sort 是对list 进行原地址排序,也就是改变原有的 list ...
假设我们需要对一个字符串列表按照字母频率进行排序,即出现频率高的字母排在前面。以下是解决该问题的Python代码: importcollectionsdefsort_by_frequency(lst):counter=collections.Counter()forsinlst:counter.update(s)returnsorted(lst,key=lambdax:counter[x])words=['apple','banana','cherry','apple','banana'...
函数counter是一个高阶函数. 该函数运行会报错,原因在于第3行, base = base + step, base被重新赋值. 改进: 使用nonlocal. nonlocal会指引inc去上层非全局作用域的本地作用域中查找. 改进之后的counter函数,f1 = counter(5)和f2 = counter(5). 比较f1和f2,值相同,但内存地址不同.因为inc是counter内的函...
words.sort(key=lambda w:w[-1]) return ' '.join(word[:-1] for word in words) 1. 2. 3. 4. 5. 2418. 按身高排序 AI检测代码解析 class Solution: def sortPeople(self, names: List[str], heights: List[int]) -> List[str]: # return [names[i] for i in sorted(range(len(names)...
t = Counter([i//100, i//10%10, i%10]) #if not (t - d): if all(d[x] >= t[x] for x in t): ans.append(i) return ans nums = set() # 偶数集 even = [(i, x) for i, x in enumerate(digits) if x % 2 == 0] ...
Python学习笔记2:collections模块的Counter类 Counter类的目的是用来跟踪值出现的次数。它是一个无序的容器类型,以字典的键值对形式存储,其中元素作为key,其计数作为value。计数值可以是任意的Interger(包括0和负数)。 常见做法 sum(c.values()) # 继承自字典的.values()方法返回values的列表,再求和 c.clear() ...
deepsort =Noneobject_counter = {} object_counter1 = {} line = [(100,500), (1050,500)]definit_tracker():globaldeepsort cfg_deep = get_config() cfg_deep.merge_from_file("deep_sort_pytorch/configs/deep_sort.yaml") deepsort= DeepSort(cfg_deep.DEEPSORT.REID_CKPT, ...
List.sort(reverse=TrueorFalse,key=func_name) In the above syntax, we can see the first one is very simple, and if it just specified as sort(), then it will by default sort the elements in ascending order and the “func” parameter, which is used to specify any of the sorting criter...
class Solution(object): def frequencySort(self, s): """ :type s: str :rtype: str """ import collections c = collections.Counter(s) tup = [] for key in c: tup.append((key, c[key])) tup.sort(key = lambda x:x[1], reverse = True) res = "" for t in tup: res += t[...
Python Real-time multi-camera multi-object tracker using YOLO varients trackingcounteryolovehiclecrop-imagevehicle-trackingrealtime-trackingreal-time-analyticsyolov3deepsortcountsyolov4yolov5yolov5-deepsortyolov6yolov7multiobject-trackingyolov6-deepsortyolov7-deepsortyolov8 ...