我正在计数txt文件中的所有字母，然后按降序显示 [英] I'm trying to count all letters in a txt file then display in descending order

问题描述

如标题所示：

到目前为止，我在我的代码中工作，但我无法按顺序显示信息。目前，它只是随机显示信息。

So far this is where I'm at my code does work however I am having trouble displaying the information in order. Currently it just displays the information randomly.

def frequencies(filename):
    infile=open(filename, 'r')
    wordcount={}
    content = infile.read()
    infile.close()
    counter = {}
    invalid = "‘'`,.?!:;-_\n—' '"

    for word in content:
        word = content.lower()
        for letter in word:
            if letter not in invalid:
                if letter not in counter:
                    counter[letter] = content.count(letter)
                    print('{:8} appears {} times.'.format(letter, counter[letter]))

任何帮助将不胜感激。

推荐答案

按降序显示需要在搜索循环之外，否则将在遇到时显示。

Displaying in descending order needs to be outside your search-loop otherwise they will be displayed as they are encountered.

使用内置的 已排序 （您需要设置 reverse -argument！）

Sorting in descending order is quite easy using the built-in sorted (you'll need to set the reverse-argument!)

但是python是包含电池，而且已经有一个< a href =https://docs.python.org/library/collections.html#collections.Counter =nofollow noreferrer> 计数器 。所以它可以是简单的：

However python is batteries included and there is already a Counter. So it could be as simply as:

from collections import Counter
from operator import itemgetter

def frequencies(filename):
    # Sets are especially optimized for fast lookups so this will be
    # a perfect fit for the invalid characters.
    invalid = set("‘'`,.?!:;-_\n—' '")

    # Using open in a with block makes sure the file is closed afterwards.
    with open(filename, 'r') as infile:  
        # The "char for char ...." is a conditional generator expression
        # that feeds all characters to the counter that are not invalid.
        counter = Counter(char for char in infile.read().lower() if char not in invalid)

    # If you want to display the values:
    for char, charcount in sorted(counter.items(), key=itemgetter(1), reverse=True):
        print(char, charcount)

计数器已经有一个 most_common 方法，但是您想要显示所有字符和数字，因此在这种情况下不太合适。然而，如果你只想知道x最常见的数值，那么它将是合适的。

The Counter already has a most_common method but you want to display all characters and counts so it's not a good fit in this case. However if you only want to know the x most common counts then it would suitable.

这篇关于我正在计数txt文件中的所有字母，然后按降序显示的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！