Question

该函数打印出文件中字母的单独频率但我无法忽略非字母，我只想在计算每个字母的百分比频率时计算字母数。这就是我到目前为止：

from string import ascii_lowercase as lowercase

def calcFrequencies(file):
    """Enter file name in quotations. Shows the frequency of letters in a file"""
    infile = open(file)
    text = infile.read()
    text = text.lower()

    text_length = len(text)
    counts = [0]*26

    for i in range(26):
        char=lowercase[i]
        counts[i] = 100*text.count(char)/text_length
        print("{:.1f}% of the characters are '{}'".format(counts[i],char))
    infile.close()

Answer 1

使用filter

>>> text = "abcd1234efg"
>>> filter(str.isalpha, text)
'abcdefg'

Answer 2

您可以使用join方法使用列表推导（比genexp更快）在计数之前仅使用字母字符重新分配字符串：

text = ''.join([char for char in text if char.isalpha()])

Python：如何忽略字符串中的非字母？

2 个答案: