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(python) I keep getting an IndexError: string index out of range

I am trying to solve the question
Implement the ​mapper​, ​mapFileToCount​, which takes a string (text from a file) and returns the number of capitalized words in that string. A word is defined as a series
of characters separated from other words by either a space or a newline. A word is capitalized if its first letter is capitalized (A vs a).
and my python code currently reads
def mapFileToCount(s):
lines = (str(s)).splitlines()
words = (str(lines)).split(" ")
up = 0
for word in words:
if word[0].isupper() == True:
up = up + 1
return up
However I keep getting the error IndexError: string index out of range
please help

For now
given Hi huy \n hi you there
lines will be ['Hi huy ', ' hi you there']
words will be ["['Hi", 'huy', "',", "'", 'hi', 'you', "there']"] as you use the str(lines) to split on
I'd suggest you split on any whitespace at once with words = re.split("\s+", s).
Then the problem of IndexError comes in cases like Hi where are you__ (_ is space), when you split there will be an empty string at the end, and you can't access the first char char of this, so just add a condition in the if
if word because 0-size word are False, and other True
if word[0].isupper() for you test
import re
def mapFileToCount(s):
words = re.split("\s+", s)
up = 0
for word in words:
if word and word[0].isupper():
up = up + 1
return up

The string index out of range means that the index you are trying to access does not exist in a string. That means you're trying to get a character from the string at a given point. If that given point does not exist , then you will be trying to get a character that is not inside of the string.
In your code its that word[0].

extracting words from a string without using the .split() function

I coded this in order to get a list full of a given string words .
data=str(input("string"))
L=[]
word=""
for i in data:
if i.isalpha() :
word+=i
elif :
L.append(word)
word=""
but, when I run this code it doesn't show the last word !

You can simply split words on a string using str.split() method, here is a demo:
data = input("string: ")
words = data.split()
L = []
for word in words:
if word.isalpha():
L.append(word)
print(L)
Note that .split() splits a string by any whitespace character by default, if you want for example to split using commas instead, you can simply use data.split(",").

You are not getting the last word into the list because it does not have non-alpha character to make it pass to the else stage and save the word to list.
Let's correct your code a little. I assume you want to check the words in the string but not characters(because what you are doing right now is checking each charackter not words.):
data=input("Input the string: ") #you don't need to cast string to string (input() returns string)
data = data+' ' # to make it save the last word
l=[] #variable names should be lowercase
word=""
for i in data:
if i.isalpha() :
word+=i
else: # you shouldn't use elif it is else if no condition is provided
l.append(word)
word=" " # not to make each word connected right after each other

Convert titlecase words in the string to lowercase words

I want to convert all the titlecase words (words starting with uppercase character and having rest of the characters as lowercase) in the string to the lowercase characters. For example, if my initial string is:
text = " ALL people ARE Great"
I want my resultant string to be:
"ALL people ARE great"
I tried the following but it did not work
text = text.split()
for i in text:
if i in [word for word in a if not word.islower() and not word.isupper()]:
text[i]= text[i].lower()
I also checked related question Check if string is upper, lower, or mixed case in Python.. I want to iterate over my dataframe and for each word that meet this criteria.

You could define your transform function
def transform(s):
if len(s) == 1 and s.isupper():
return s.lower()
if s[0].isupper() and s[1:].islower():
return s.lower()
return s
text = " ALL people ARE Great"
final_text = " ".join([transform(word) for word in text.split()])

You can use str.istitle() to check whether your word represents the titlecased string, i.e. whether first character of the word is uppercase and rest are lowercase.
For getting your desired result, you need to:
Convert your string to list of words using str.split()
Do the transformation you need using str.istitle() and str.lower() (I am using list comprehension for iterating the list and for generating a new list of words in desired format)
Join back the list to strings using str.join() as:
For example:
>>> text = " ALL people ARE Great"
>>> ' '.join([word.lower() if word.istitle() else word for word in text.split()])
'ALL people ARE great'

How do I output the acronym on one line

I am following the hands-on python tutorials from Loyola university and for one exercise I am supposed to get a phrase from the user, capatalize the first letter of each word and print the acronym on one line.
I have figured out how to print the acronym but I can't figure out how to print all the letters on one line.
letters = []
line = input('?:')
letters.append(line)
for l in line.split():
print(l[0].upper())

Pass end='' to your print function to suppress the newline character, viz:
for l in line.split():
print(l[0].upper(), end='')
print()

Your question would be better if you shared the code you are using so far, I'm just guessing that you have saved the capital letters into a list.
You want the string method .join(), which takes a string separator before the . and then joins a list of items with that string separator between them. For an acronym you'd want empty quotes
e.g.
l = ['A','A','R','P']
acronym = ''.join(l)
print(acronym)

You could make a string variable at the beginning string = "".
Then instead of doing print(l[0].upper()) just append to the string string += #yourstuff
Lastly, print(string)

How might I create an acronym by splitting a string at the spaces, taking the character indexed at 0, joining it together, and capitalizing it?

My code
beginning = input("What would you like to acronymize? : ")
second = beginning.upper()
third = second.split()
fourth = "".join(third[0])
print(fourth)
I can't seem to figure out what I'm missing. The code is supposed to the the phrase the user inputs, put it all in caps, split it into words, join the first character of each word together, and print it. I feel like there should be a loop somewhere, but I'm not entirely sure if that's right or where to put it.

Say input is "Federal Bureau of Agencies"
Typing third[0] gives you the first element of the split, which is "Federal". You want the first element of each element in the sprit. Use a generator comprehension or list comprehension to apply [0] to each item in the list:
val = input("What would you like to acronymize? ")
print("".join(word[0] for word in val.upper().split()))
In Python, it would not be idiomatic to use an explicit loop here. Generator comprehensions are shorter and easier to read, and do not require the use of an explicit accumulator variable.

When you run the code third[0], Python will index the variable third and give you the first part of it.
The results of .split() are a list of strings. Thus, third[0] is a single string, the first word (all capitalized).
You need some sort of loop to get the first letter of each word, or else you could do something with regular expressions. I'd suggest the loop.
Try this:
fourth = "".join(word[0] for word in third)
There is a little for loop inside the call to .join(). Python calls this a "generator expression". The variable word will be set to each word from third, in turn, and then word[0] gets you the char you want.

works for me this way:
>>> a = "What would you like to acronymize?"
>>> a.split()
['What', 'would', 'you', 'like', 'to', 'acronymize?']
>>> ''.join([i[0] for i in a.split()]).upper()
'WWYLTA'
>>>

One intuitive approach would be:
get the sentence using input (or raw_input in python 2)
split the sentence into a list of words
get the first letter of each word
join the letters with a space string
Here is the code:
sentence = raw_input('What would you like to acronymize?: ')
words = sentence.split() #split the sentece into words
just_first_letters = [] #a list containing just the first letter of each word
#traverse the list of words, adding the first letter of
#each word into just_first_letters
for word in words:
just_first_letters.append(word[0])
result = " ".join(just_first_letters) #join the list of first letters
print result

#acronym2.py
#illustrating how to design an acronymn
import string
def main():
sent=raw_input("Enter the sentence: ")#take input sentence with spaces
for i in string.split(string.capwords(sent)):#split the string so each word
#becomes
#a string
print string.join(i[0]), #loop through the split
#string(s) and
#concatenate the first letter
#of each of the
#split string to get your
#acronym
main()

name = input("Enter uppercase with lowercase name")
print(f'the original string = ' + name)
def uppercase(name):
res = [char for char in name if char.isupper()]
print("The uppercase characters in string are : " + "".join(res))
uppercase(name)