This is the question I was given to solve:
Create a program inputs a phrase (like a famous quotation) and prints all of the words that start with h-z.
I solved the problem, but the first two methods didn't work and I wanted to know why:
#1 string index out of range
quote = input("enter a 1 sentence quote, non-alpha separate words: ")
word = ""
for character in quote:
if character.isalpha():
word += character.upper()
else:
if word[0].lower() >= "h":
print(word)
word = ""
else:
word = ""
I get the IndexError: string index out of range message for any words after "g". Shouldn't the else statement catch it? I don't get why it doesn't, because if I remove the brackets [] from word[0], it works.
#2: last word not printing
quote = input("enter a 1 sentence quote, non-alpha separate words: ")
word = ""
for character in quote:
if character.isalpha():
word += character.upper()
else:
if word.lower() >= "h":
print(word)
word = ""
else:
word = ""
In this example, it works to a degree. It eliminates any words before 'h' and prints words after 'h', but for some reason doesn't print the last word. It doesn't matter what quote i use, it doesn't print the last word even if it's after 'h'. Why is that?
You're calling on word[0]. This accesses the first element of the iterable string word. If word is empty (that is, word == ""), there is no "first element" to access; thus you get an IndexError. If a "word" starts with a non-alphabetic character (e.g. a number or a dash), then this will happen.
The second error you're having, with your second code snippet leaving off the last word, is because of the approach you're using for this problem. It looks like you're trying to walk through the sentence you're given, character by character, and decide whether to print a word after having read through it (which you know because you hit a space character. But this leads to the issue with your second approach, which is that it doesn't print the last string. That's because the last character in your sentence isn't a space - it's just the last letter in the last word. So, your else loop is never executed.
I'd recommend using an entirely different approach, using the method string.split(). This method is built-in to python and will transform one string into a list of smaller strings, split across the character/substring you specify. So if I do
quote = "Hello this is a sentence"
words = quote.split(' ')
print(words)
you'll end up seeing this:
['Hello', 'this', 'is', 'a', 'sentence']
A couple of things to keep in mind on your next approach to this problem:
You need to account for empty words (like if I have two spaces in a row for some reason), and make sure they don't break the script.
You need to account for non-alphanumeric characters like numbers and dashes. You can either ignore them or handle them differently, but you have to have something in place.
You need to make sure that you handle the last word at some point, even if the sentence doesn't end in a space character.
Good luck!
Instead of what you're doing, you can Iterate over each word in the string and count how many of them begin in those letters. Read about the function str.split(), in the parameter you enter the divider, in this case ' ' since you want to count the words, and that returns a list of strings. Iterate over that in the loop and it should work.
Related
sentence = input("Input sentence: ")
punctuation = [" ", ",", ".", ":", "?", "!"]
interruption1 = sentence.index(punctuation)
word1 = sentence[:interruption1]
print(word1)
In this question, the main aim is to have the program print the first word that the user types by identifying a character that implies the first word has ended (the punctuation characters in the 'punctuation' variable). I want the program to accept the 'punctuation' variable within the index function but it sends an error message saying "must be str, not list". I tried for loops, they don't work here either as far as I know.
A previous question of mine gave me information that you can't use boolean values to represent a set of values in a variable, so I used a list, but now this error happens, and there is absolutely nothing on the Internet on this sort of problem (neither do I have an IT teacher or any friends that do Python), so I had to come here after about an hour of trying random combinations of code. How do I make Python accept the list and use it inside the index function? Thank you.
You don't need to use an index unless it is demanded; just keep accepting characters from the sentence until you come to a punctuation. So the simplest looping approach is:
sentence = input("Input sentence: ")
punctuation = [" ", ",", ".", ":", "?", "!"]
result = ""
for c in sentence:
if c in punctuation:
break
else:
result = result + c
print(result)
To be honest this is something you should do with regular expressions. But, that doesn't really answer your question, so - you are close, but your problem is that you're passing a list of strings instead of a single string, as your error message implies.
You should loop through each string in the list and get the first occurrence of the string in your sentence. You can use str.index() but I prefer to use str.find() which will return a -1 if the character is not found thus we don't have to mess around with error exceptions.
sentence = input("Input sentence: ")
punctuation = [" ", ",", ".", ":", "?", "!"]
matches = []
for character in punctuation:
match = sentence.find(character)
#If the character is found, save to a separate list.
#No match means value is -1, so ignore it using >0
if match >0:
matches.append(match)
# Now find the match that occurs first:
first_match_index = min(matches)
# Return first word
first_word = sentence[:first_match_index]
print(first_word)
How do I make Python accept the list and use it inside the index function?
You can't str.index only accepts str.
I tried for loops, they don't work
A for loop could work
iterate over sentence while keeping track of the index
for each character check to see if it is in punctuation
if it isn't in punctuation
continue with the next character
if it is in punctuation
use the index to extract the first word using a slice: sentance[:index]
stop iterating
I'm newbie in Python so that I have a question. I want to change letter in word if the first letter appears more than once. Moreover I want to use input to get the word from user. I'll present the problem using an example:
word = 'restart'
After changes the word should be like this:
word = 'resta$t'
I was trying couple of ideas but always I got stuck. Is there any simple sollutions for this?
Thanks in advance.
EDIT: In response to Simas Joneliunas
It's not my homework. I'm just finished reading some basic Python tutorials and I found some questions that I couldn't solve on my own. My first thought was to separate word into a single letters and then to find out the place of the letter I want to replace by "$". I have wrote that code but I couldn't came up with sollution how to get to specific place and replace it.
word = 'restart'
how_many = {}
for x in word:
how_many=+1
else:
how_many=1
for y in how_many:
if how_many[y] > 0:
print(y,how_many[y])
Using str.replace:
s = "restart"
new_s = s[0] + s[1:].replace(s[0], "$")
Output:
'resta$t'
Try:
"".join([["$" if ch in word[:i] else ch for i, ch in enumerate(word)])
enumerate iterates through the string (i.e. a list of characters) and keeps a running index of the iteration
word[:i] checks the list of chars until the current index, i.e. previously appeared characters
"$" if ch in word[:i] else ch means replace the character at existing position with $ if it appears before others keep the character
"".join() joins the list of characters into a single string.
This is where the python console is handy and lets you experiment. Since you have to keep track of number of letters, for a good visual I would list the alphabet in a list. Then in the loop remove from the list the current letter. If letter does not exist in the list replace the letter with $.
So check if it exists first thing in the loop, if it exists, remove it, if it doesn’t exist replace it from example above.
I'm trying to write a script that can take doubled letters (aa or tt, for instance) and change them to that letter followed by ː, the length symbol (aa would become aː, and tt would become tː). I want to do this by iterating through the string, and replacing any character in the string that's the same as the last one with a ː. How do I do that?
You could try something like this. I iterated through string and checked each letter against the previous letter. If they match it performs the replacement if not it moves on and stores the new previous letter in previousletter. Also I used the .lower() method to mactch letters even if one is capitalized and one is not.
string = "Tthis is a testt of the ddouble letters"
previousletter = string[0]
for letter in string:
if letter.lower() == previousletter.lower():
string = string.replace("%s%s" % (previousletter, letter) , "%s:" % (letter))
previousletter = letter
print(string)
And here is the output:
t:his is a test: of the d:ouble let:ers
I hope this helps and feel free to ask any questions on the code that I used. Happy programming!
I am trying to create a dictionary of list that the key is the anagrams and the value(list) contains all the possible words out of that anagrams.
So my dict should contain something like this
{'aaelnprt': ['parental', 'paternal', 'prenatal'], ailrv': ['rival']}
The possible words are inside a .txt file. Where every word is separated by a newline. Example
Sad
Dad
Fruit
Pizza
Which leads to a problem when I try to code it.
with open ("word_list.txt") as myFile:
for word in myFile:
if word[0] == "v": ##Interested in only word starting with "v"
word_sorted = ''.join(sorted(word)) ##Get the anagram
for keys in list(dictonary.keys()):
if keys == word_sorted: ##Heres the problem, it doesn't get inside here as theres extra characters in <word_sorted> possible "\n" due to the linebreak of myfi
print(word_sorted)
dictonary[word_sorted].append(word)
If every word in "word_list.txt" is followed by '\n' then you can just use slicing to get rid of the last char of the word.
word_sorted = ''.join(sorted(word[:-1]))
But if the last word in "word_list.txt" isn't followed by '\n', then you should use rstrip().
word_sorted = ''.join(sorted(word.rstrip()))
The slice method is slightly more efficient, but for this application I doubt you'll notice the difference, so you might as well just play safe & use rstrip().
Use rstrip(), it removes the \n character.
...
...
keys == word_sorted.rstrip()
...
You should try to use the .rstrip() function in your code, it will remove the "\n"
Here you can check it .rstrip()
strip only removes characters from the beginning or end of a string.
Use rstrip() to remove \n character
Also you can use replace syntax, to replace newline with something else.
str2 = str.replace("\n", "")
So, I see a few problems here, how is anything getting into the dictionary, I see no assignments? Obviously you've only provided us a snippet, so maybe that's elsewhere.
You're also using a loop when you could be using in (it's more efficient, truly it is).
with open ("word_list.txt") as myFile:
for word in myFile:
if word[0] == "v": ##Interested in only word starting with "v"
word_sorted = ''.join(sorted(word.rstrip())) ##Get the anagram
if word_sorted in dictionary:
print(word_sorted)
dictionary[word_sorted].append(word)
else:
# The case where we don't find an anagram in our dict
dictionary[word_sorted] = [word,]
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)