写元音计数器

Question

This is my homework assignment:

Write function vowelCount() that takes a string as input and counts and prints the number of occurrences of vowels in the string.

vowelCount ( ' Le Tour de France ' ) a, e, i, o, and u appear, respectively, 1, 3, 0, 1, 1 times.

This is what I've done so far and it's not working! What do I do?

def vowelCount(sentence):
    sentence = sentence.lower()
    vowels = "aeiou"
    count = 0
    if vowels in sentence:
        count = +1
        print("a, e, i, o, u, appear, respectively," count "times.")

I'm so bad with Python that I can never do my homework on my own. I might as well just give up trying to learn.

Answer 1

You are doing wrong initialization.

vowels = "aeiou"

You should declare it as list or dictionary. Now the problem with your solution is that you are checking if "vowels" which you have initialized as "aeiou" is present in incoming string or not

if vowels in sentence:

So here you are checking that "aeiou", the whole string is present in the incoming sentence or not. You are not checking for individual vowel and individual character.

The solution will we like iterating all over the sentence from 0 to n-1 where n is its length and check each character.

 def count(string):
    #we use hashmap to make lookup operation cheap
    mp = {'a':1,'e':1,'i':1,'o':1,'u':1}
    n = len(s)
    count = 0
    for i in range(n):  #iterating for every element in string
        if s[i] in mp:   #checking if it is vowel or not
            count += 1
    return count