您可以使用翻译者配方来删除所有不在中的字符
alpha。由于这样做使make
letters中除了字符外仅包含其他字符
alpha，因此它
n是正确的分母。
然后，您可以使用a
collections.defaultdict(int)来计数字母的出现：
import collectionsimport stringdef translator(frm='', to='', delete='', keep=None): # Python Cookbook Recipe 1.9 # Chris Perkins, Raymond Hettinger if len(to) == 1: to = to * len(frm) trans = string.maketrans(frm, to) if keep is not None: allchars = string.maketrans('', '') # delete is expanded to delete everything except # what is mentioned in set(keep)-set(delete) delete = allchars.translate(allchars, keep.translate(allchars, delete)) def translate(s): return s.translate(trans, delete) return translatealpha = 'abcdefghijklmnopqrstuvwxyz'keep_alpha=translator(keep=alpha)while True: speech = raw_input("Enter file name:") wholeFile = open(speech, 'r+').read() lowlet = wholeFile.lower() letters = keep_alpha(lowlet) n = len(letters) occurrences = collections.defaultdict(int) for x in letters: occurrences[x]+=1 for x in occurrences: print x, occurrences[x], occurrences[x]/float(n)
