replacing a string in python list with another string

Question

currently my loops stops at replacing 1 with the answer. how do i loop it so it replaces all 4 blanks with the 4 answers?

easyQuiz = "There are ___1___ countries in the world. The countries with the biggest landmass is ___2___. The coldest continent in the world is ___3___. ___4___ is the capital of China"

blanks = ["___1___","___2___","___3___","___4___"]

easyAnswer = ["195","Russia","Antartica","Beijing"]

#asks users to choose difficulty level
question = raw_input("Shall we start? Easy, Medium, Hard?")


if question == "Easy" or question == "easy":
    answerChoice = easyAnswer

answerChoice = answerList(question)
newprompt = []
newlist = []
index = 0
maxblanks = 3

for quizwords in difficulty(question).split():

    if quizwords == "1" :
        quizwords = quizwords.replace("1",answerChoice[index])


    elif quizwords == "2" :
        quizwords = quizwords.replace("2",answerChoice[index])

        index = index + 1
    newlist.append(quizwords)
    joinedlist = " ".join(newlist)

You probably want to use string formatting here: http://pyformat.info/ — Patrick Haugh, Feb 01 '18 at 15:38
Also, if `quizwords == "1"`, you can just do `quizwords = answerChoice[index]` instead of `replace`, but is this really what you intended? — tobias_k, Feb 01 '18 at 15:38
If you expect any help, post a MCVE including expected results (https://stackoverflow.com/help/mcve) — bruno desthuilliers, Feb 01 '18 at 15:38

score 2 · Answer 1 · answered Feb 01 '18 at 15:42

2

You can use string formatting

def easyQuiz(vals):
      return """
There are {} countries in the world.
The countries with the biggest landmass is {}.
The coldest continent in the world is {}.
{} is the capital of China""".format(*vals)

print(easyQuiz(("___1___","___2___","___3___","___4___")))
# There are ___1___ countries in the world.
# The countries with the biggest landmass is ___2___.
# The coldest continent in the world is ___3___.
# ___4___ is the capital of China

print(easyQuiz(("195","Russia","Antartica","Beijing")))
# There are 195 countries in the world.
# The countries with the biggest landmass is Russia.
# The coldest continent in the world is Antartica.
# Beijing is the capital of China

answered Feb 01 '18 at 15:42

dfrib

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thank you! what does the * in the .format(*vals) mean? – nicholas gwee Feb 11 '18 at 06:52
@nicholasgwee you are welcome. It's [tuple unpacking](https://stackoverflow.com/questions/2238355/what-is-the-pythonic-way-to-unpack-tuples). – dfrib Feb 11 '18 at 15:52
may i ask how can i replace only the 2nd {} in the question although there are four values – nicholas gwee Feb 13 '18 at 14:48
@nicholasgwee as a simple approach you could still replace all 4, but for 1, 2, 4 just insert the placeholders. E.g. `print(easyQuiz(("___1___","Russia","___3___","___4___")))`. – dfrib Feb 13 '18 at 15:14
Thank you so much i managed to format the blanks based on users input for the correct answers! much appreciated! – nicholas gwee Feb 14 '18 at 16:03
@nicholasgwee happy to help! – dfrib Feb 14 '18 at 17:41

score 0 · Answer 2 · answered Feb 01 '18 at 15:41

You can zip the blanks with the corresponding easyAnswer and replace those in a loop.

for blank, answer in zip(blanks, easyAnswer):
    easyQuiz = easyQuiz.replace(blank, answer)

Or zip to a dict and use re.sub with a callback:

answer_dict = dict(zip(blanks, easyAnswer))
result = re.sub("___\d___", lambda m: answer_dict[m.group()], easyQuiz)

score 0 · Answer 3 · answered Feb 01 '18 at 15:45

You can use string formatting with regex:

import re
easyQuiz = "There are ___1___ countries in the world. The countries with the biggest landmass is ___2___. The coldest continent in the world is ___3___. ___4___ is the capital of China"
easyAnswer = ["195","Russia","Antartica","Beijing"]
answers = re.sub('___\d+___', '{}', easyQuiz).format(*easyAnswer)

Output:

'There are 195 countries in the world. The countries with the biggest landmass is Russia. The coldest continent in the world is Antartica. Beijing is the capital of China'

score 0 · Answer 4 · answered Feb 01 '18 at 15:57

Question is a bit confusing, especially 'difficulty' and 'answerList'. Assuming, 'answerList' returns a list of four answers. Your loop will depend upon difficulty(question).split(). My hunch is your loop is iterating only once, and the index is not getting updated after that hence loops stops at replacing 1 with the answer.

replacing a string in python list with another string

4 Answers4