Python说文解字_计数器

from collections import Counter

response = [
    "vanilla",
    "chocolate",
    "vanilla",
    "vanilla",
    "caramel",
    "strawberry",
    "vanilla"
]

print("The children voted for {} ice cream".
      format(Counter(response).most_common()[][]))
# The children voted for vanilla ice cream

# most_common()中，用于只获取出现次数最多的元素,返回由（key，count）元组组成的列表按照计数排序。

# import collections
obj = Counter('aabbccc')
print(obj)
#输出：Counter({'c': , 'a': , 'b': })

# elements()
obj = Counter('aabbccc')
print(sorted(obj.elements()))
#输出：['a', 'a', 'b', 'b', 'c', 'c', 'c']
for k in obj.elements():   #遍历打印obj所有元素
    print(k)

# most_common(指定一个参数n，列出前n个元素，不指定参数，则列出所有)
obj = Counter('aabbbcccc')
print(obj.most_common())

# items(从dict类中继承的方法)
obj = Counter('aabbbcccc')
print(obj.items())

for k,v in obj.items():
    print(k,v)

#输出：dict_items([('b', ), ('c', ), ('a', )])
#     b
#     c
#     a
#输出：[('c', ), ('b', )]

# update(增加元素)
obj = Counter(['',''])
obj.update(['',''])
print(obj)
#输出：Counter({'': , '': , '': })

# subtract(原来的元素减去新传入的元素)
obj = Counter(['','',''])
obj.subtract(['',''])
print(obj)
#输出：Counter({'': , '': , '': , '': -})

from collections import Counter

response = [
    "vanilla",
"chocolate",
"vanilla",
"vanilla",
"caramel",
"strawberry",
"vanilla"
]

print("The children voted for {} ice cream".
      format(Counter(response).most_common()[][]))
# The children voted for vanilla ice cream

# most_common()中，用于只获取出现次数最多的元素,返回由（key，count）元组组成的列表按照计数排序。

# import collections
obj = Counter('aabbccc')
print(obj)
#输出：Counter({'c': 3, 'a': 2, 'b': 2})

# elements()
obj = Counter('aabbccc')
print(sorted(obj.elements()))
#输出：['a', 'a', 'b', 'b', 'c', 'c', 'c']
for k in obj.elements():   #遍历打印obj所有元素
print(k)

# most_common(指定一个参数n，列出前n个元素，不指定参数，则列出所有)
obj = Counter('aabbbcccc')
print(obj.most_common())

# items(从dict类中继承的方法)
obj = Counter('aabbbcccc')
print(obj.items())

for k,v in obj.items():
    print(k,v)

#输出：dict_items([('b', 3), ('c', 4), ('a', 2)])
#     b 3
#     c 4
#     a 2
#输出：[('c', 4), ('b', 3)]

# update(增加元素)
obj = Counter(['11','22'])
obj.update(['22','55'])
print(obj)
#输出：Counter({'22': 2, '11': 1, '55': 1})

# subtract(原来的元素减去新传入的元素)
obj = Counter(['11','22','33'])
obj.subtract(['22','55'])
print(obj)
#输出：Counter({'11': 1, '33': 1, '22': 0, '55': -1})