How to reverse vowels in string and return it-CodePudding

I am Trying to make a program in Python to reverse the vowels in a string and return the string like this:

vow = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']
vowin = []
place = []

def string(string):
    for ch in string:
        if ch in vow:
            vowin.append(ch)
        else:
            continue
    for ch in string:
        if ch in vow:
            index1 = string.index(ch)
            place.append(index1)
        else:
            continue
    place.reverse()
    str = list(string)
    for ch in range(len(place)):
        str[place[ch]] = vowin[ch]

    new = ''.join(str)
    return new

print(string('Queen'))

When I try to run a word with a double vowel like queen it makes all other vowels into e too like the code above.

Output: Qeeen

but if I input hello the output is holle like it should.

Anyone know what the problem is?

CodePudding user response：

No indexing required if vowin is used as a LIFO (last in, first out) stack. First pass, fill with vowels in order. Second pass, each vowel is replaced from vowin via .pop() which removes the last value.

vow = 'aeiouAEIOU'

def string(s):
    vowin = []  # make sure to reset each call to string()
    place = []

    for ch in s:
        if ch in vow:
            vowin.append(ch)  # store vowels in order found

    for ch in s:
        if ch in vow:                  # if vowel
            place.append(vowin.pop())  #  replace in reverse order
        else:
            place.append(ch)           # else copy as is

    new = ''.join(place)
    return new

print(string('Queen'))
print(string('abcdefghijklmnopqrstuvwxyz'))
print(string('bookkeeping'))

Output:

Qeeun
ubcdofghijklmnepqrstavwxyz
biekkeopong

CodePudding user response：

Change this part:

for ch in string:
    if ch in vow:
        index1 = string.index(ch)
        place.append(index1)
    else:
        continue

for i, ch in enumerate(string):
    if ch in vow:
        place.append(i)

CodePudding user response：

this code uses a list comprehension to extract the vowels from the input string. the resampling of the final string is done by using a ternary conditional.

inp = input()
vow = 'aeiouAEIOU'
vow_lst = [char for char in inp if char in vow]

res = ''
for char in inp:
    res  = vow_lst.pop() if char in vow else char
print(res)