Capitalization of each sentence in a string in Python 3

Question

This should be easy but somehow I\'m not quite getting it.

My assignment is:

Write a function sentenceCapitalizer that has one parameter of type

Answer 1

You are trying to use a string method on the wrong object; words is list object containing strings. Use the method on each individual element instead:

words2 = [word.capitalize() for word in words]

But this would be applying the wrong transformation; you don't want to capitalise the whole sentence, but just the first letter. str.capitalize() would lowercase everything else, including the J in Joe:

>>> 'my name is Joe'.capitalize()
'My name is joe'    

Limit yourself to the first letter only, and then add back the rest of the string unchanged:

words2 = [word[0].capitalize() + word[1:] for word in words]

Next, a list object has no .join() method either; that too is a string method:

string2 = '. '.join(words2)

This'll join the strings in words2 with the '. ' (full stop and space) joiner.

You'll probably want to use better variable names here; your strings are sentences, not words, so your code could do better reflecting that.

Together that makes your function:

def sentenceCapitalizer (string1: str):
    sentences = string1.split(". ")
    sentences2 = [sentence[0].capitalize() + sentence[1:] for sentence in sentences]
    string2 = '. '.join(sentences2)
    return string2

Demo:

>>> def sentenceCapitalizer (string1: str):
...     sentences = string1.split(". ")
...     sentences2 = [sentence[0].capitalize() + sentence[1:] for sentence in sentences]
...     string2 = '. '.join(sentences2)
...     return string2
... 
>>> print (sentenceCapitalizer("hello. my name is Joe. what is your name?"))
Hello. My name is Joe. What is your name?