Python uppercase conversion conditions

[pyzyx3qwerty]

Try this:

first = input("Enter a sentence : ")
second = ""
vowels = ['a','e','i','o','u']
for i in first:
    if i in vowels:
        second += i.upper()
    else :
        second += i
print( second)

And output:

Output:
Enter a sentence : This is a test
ThIs Is A tEst