python collections 里面的Counter 统计所有出现的字符数量

from collections import Counter

c_num = Counter('Hello world')  # 统计出现的每个字符数量print(c_num)

for key, value in c_num.items():    print('%s: %s个' % (key, value))

print(c_num.most_common(2))  # 随机获取2个元素并且返回格式为：[('1',3),(' ',1)]print(c_num.most_common(4))

# # Counter({'l': 3, 'o': 2, 'H': 1, 'e': 1, ' ': 1, 'w': 1, 'r': 1, 'd': 1})# H: 1个# e: 1个# l: 3个# o: 2个#  : 1个# w: 1个# r: 1个# d: 1个# [('l', 3), ('o', 2)]# [('l', 3), ('o', 2), ('H', 1), ('e', 1)]