from collections import Counter>>> c = Counter('hello,world')Counter({'l': 3, 'o': 2, 'e': 1, 'd': 1, 'h': 1, ',': 1, 'r': 1, 'w': 1})

 | __init__(self, iterable=None, **kwds) |  Create a new, empty Counter object. And if given, count elements |  from an input iterable. Or, initialize the count from another mapping |  of elements to their counts. | |  >>> c = Counter()       # a new, empty counter |  >>> c = Counter('gallahad')     # a new counter from an iterable |  >>> c = Counter({'a': 4, 'b': 2})   # a new counter from a mapping |  >>> c = Counter(a=4, b=2)     # a new counter from keyword args

>>> c = Counter(numbers) # c 存儲了每個數字的頻率>>> c.most_common()  # 所有數字按照頻率排序。如果 most_common 接受了 int 參數 n，將返回頻率前n 的數據，否則會返回所有的數據[('1', 8), ('2', 6), ('6', 6), ('5', 5), ('4', 5), ('7', 5), ('0', 3), ('9', 3), ('8', 2), ('3', 1)]

print('Counter類型的應用') c = Counter("dengjingdong") #c = Counter({'n': 3, 'g': 3, 'd': 2, 'i': 1, 'o': 1, 'e': 1, 'j': 1}) print("原始數據：",c) print("最多的兩個元素：",c.most_common(2))#輸出數量最多的元素 print("d的個數：",c['d'])#輸出d的個數 print(c.values())#輸出字典的value列表 print(sum(c.values()))#輸出總字符數 print(sorted(c.elements()))#將字典中的數據，按字典序排序 print('/n/n') """ #刪除所有d元素 del c['d'] b = Counter("dengxiaoxiao") #通過subtract函數刪除元素，元素個數可以變成負數。 c.subtract(b) """  """ 可以添加數據 b = Counter("qinghuabeida") c.update(b) """