Python list index not in order-CodePudding

I'm trying to make it so that my text alternates between upper and lower case like the question ask. It seems to skip 3 in the indexing and I can't figure out why.

sentence = input("Write a sentence")

newList = []
for i in range(len(sentence)):
    if sentence[i] != " ":
        newList.append(sentence[i])


listJoint = "".join(newList)
newList2 = []

for i in range(len(listJoint)):
    if (listJoint.index(listJoint[i]) % 2) == 0:
        print(listJoint.index(listJoint[i]))
        newList2.append(listJoint[i].upper())
    elif (listJoint.index(listJoint[i]) % 2) != 0:
        print(listJoint.index(listJoint[i]))
        newList2.append(listJoint[i].lower())

print(newList2)

#newListJoint = "".join(newList2)
#print(newListJoint[::-1])

Thanks in advance List index doesn't go 0 1 2 3 4

CodePudding user response：

The function .index() finds the first occurrence of that letter. 'L' occurs at index 2 and 3 so it would return 2 for both L's.

CodePudding user response：

Iterate through each character of the string and alternate upper/lower methods.

sentence = "Hello"

alternated_sentence = ''
for i, char in enumerate(sentence):
    if i % 2:
        alternated_sentence  = char.upper()
    else:
        alternated_sentence  = char.lower()

print(alternated_sentence)
#hElLo

CodePudding user response：

sentence = input("Write a sentence:")
# Remove spaces (as per your question)
sentence = sentence.replace(' ', '')
# Reverse the string order (as per your question)
sentence = sentence[::-1]

result = []
for i in range(len(sentence)):
  if(i%2==1):
    result.append(sentence[i].lower())
  else:
    result.append(sentence[i].upper())

print(''.join(result))

Here's the solution. The above code would give output as follows:

Write a sentence: Hello world
DlRoWoLlEh

CodePudding user response：

Thanks to everyone for the responses, I never realised index method referenced the first instance of the character. I have it working now:

sentence = input("Write a sentence")

newList = []
for i in range(len(sentence)):
    if sentence[i] != " ":
        newList.append(sentence[i])


listJoint = "".join(newList)
newList2 = []


for i, value in enumerate(newList):
    if i % 2 == 0:
        newList2.append(listJoint[i].upper())
    elif i % 2 !=0:
        newList2.append(listJoint[i].lower())

newListJoint = "".join(newList2)
print(newListJoint[::-1])