python - Letter Frequency

Question

編寫一個名爲hist（）的Python函數，它將一個字符串作爲參數，並通過以字母大寫打印每個字母的次數來創建其字符串頻率的直觀表示形式，每個字母在一個單獨的行上，從最多到最少分組。

Answer 1

你的代碼很相似，你不需要閱讀該文件。

def hist(inputstr): 
    lowlet = inputstr.upper() 
    alphas = 'abcdefghijklmnopqrstuvwxyz'.upper() 
    occurrences = dict((letter, 0) for letter in alphas) 
    total = 0 
    for letter in lowlet: 
     if letter in occurrences: 
      total += 1 
      occurrences[letter] += 1 
    letcount = sorted(occurrences.iteritems(),key = lambda x:-x[1]) 
    for letter, count in letcount: 
     if count>0: 
      print letter*count 

Answer 2

一個更簡單的方法是：

import string 
def hist(s): 
    d = {} 
    for i in s.upper(): 
     if i.isalpha(): 
      d[i] = d[i] + 1 if i in d else 1 
    for k in sorted(d.keys()): 
     print k*d[k]