计算文本文件中的特定字符

Question

如何计算特定字符（非空格）在文本文件中出现的次数？ （即“，”“。”“a”“k”“m”）

这是我目前所拥有的：

file = open("filename.txt","r")

num_char = 0
num_words = 0
num_lines = 0


for line in file:
    words = line.split()
    num_lines += 1
    num_words += len(words)
    num_char += len(line)



print ("Character count:\t" + str(num_char))
print ("Word count:\t\t" + str(num_words))
print ("Line count:\t\t" + str(num_lines))
print ("Distribution of characters: ")

到目前为止的分发代码

text = file.read()
file.close()
words = text.strip()
final = words.lower()
for i in range(len(words)):
    first = final.count("a")
    second = final.count("b")
print (first)
print (second)

这为我提供了我想要的 a 和 b 输出，但为每个字符编写每一行代码效率不高。我将如何遍历每个可能的字符，然后打印出计数？

Answer 1

使用collections.Counter。

from collections import Counter

file = open("filename.txt", "r")

num_char = 0
num_words = 0
num_lines = 0
char_distribution = Counter()

for line in file:
    words = line.split()
    num_lines += 1
    num_words += len(words)
    num_char += len(line)
    char_distribution += Counter(line.lower())

print("Character count:\t{}".format(num_char))
print("Word count:\t\t{}".format(num_words))
print("Line count:\t\t{}".format(num_lines))
print("Distribution of characters: ")
for char, count in sorted(char_distribution.items()):
    if char.isalpha() or char in ',.':
        print("\t{}\t\t{}".format(char, count))