如何修复TypeError:元音()缺少必需的位置参数：'filehandle'？

Question

编写一个将文本文件的内容读入字符串的程序

def vowels(filehandle):
    num_vowel = 0
    vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']
    for c in filehandle:
        if c in vowels:
            num_vowel = num_vowel+1
    return num_vowel

def consonants(filehandle):
    num_con = 0
    for c in filehandle:
        if c >= 'a' and c <= 'z':
            if c not in vowels:
                num_con = num_con+1
        elif c>='A' and c<='Z':
            if c not in vowels:
                num_con = num_con+1
    return num_con

def case(filehandle):
    uppercase = 0
    lowercase = 0
    for c in filehandle:
        if c>='a' and c<='z':
            uppercase=uppercase+1
        elif c>='A' and c<= 'Z':
            lowercase=lowecase+1
    return uppercase, lowercase

def main():
    vowel = vowels()
    consonants = consonants()
    uppercase, lowercase = case()
    try:
        filename=input('Enter name of text file: ')
        filehandle=open('words.txt', 'r')

        print('Vowels:', vowels)
        print('Consonants:', consonants)
        print('Uppercase:', uppercase)
        print('Lowercase:', lowercase)

        filehandle.close()
    except IOError:
        print('FILE NOT FOUND')


main()

当我尝试运行这个程序时，它给出了这个错误

line 31, in main
    vowel = vowels()
TypeError: vowels() missing 1 required positional argument: 'filehandle'

我对python和函数的使用还是个新手，所以如果你能用任何人都能理解的方式来描述它，我将不胜感激。

Answer 1

vowels()的定义表明它需要一个参数：

def vowels(filehandle):

但是在main()中，您可以不带参数地调用它：

vowel = vowels()