字典定义x={}

get()函数

get（参数一，参数二）

参数一：

需要查找的关键词

参数二：

如果关键词不存在get返回的默认值

字典的更新

update（）函数，字典y的元素，去更新字典x的元素，少补，异同

字典推导式

y={for in if }

词频统计

p = '''

I heard the echo, from the valleys and the heart

Open to the lonely soul of sickle harvesting

Repeat outrightly, but also repeat the well-being of

Eventually swaying in the desert oasis

I believe I am

Born as the bright summer flowers

Do not withered undefeated fiery demon rule

Heart rate and breathing to bear the load of the cumbersome

Bored

'''

lines = p.strip().split('\n')
words_cnt = {}
for line in lines:
    line = line.replace(',', '').lower()
    words = line.split(' ')
    for word in words:
        words_cnt[word] = words_cnt.get(word, 0) + 1

words_lst = list(zip(words_cnt.values(), words_cnt.keys()))
words_lst.sort()
words_lst.reverse()
for word in words_lst:
    print(word[1], words_cnt[word[1]])

'''三个单引号用来输入多段落字符串