How do I allow only the latest inputs to be saved - Python - python

How do I implement a simple code that will only save the student's latest 3 scores? If the test is repeated later, the old score should be replaced.
Thank you.
This is the code that asks the user the questions and saves the results in the txt. files.
import random
import math
import operator as op
correct_answers = 0
def test():
num1 = random.randint(1, 10)
num2 = random.randint(1, 10)
ops = {
'+': op.add,
'-': op.sub,
'*': op.mul,
}
keys = list(ops.keys())
rand_key = random.choice(keys)
operation = ops[rand_key]
correct_result = operation(num1, num2)
print ("What is {} {} {}?".format(num1, rand_key, num2))
user_answer= int(input("Your answer: "))
if user_answer != correct_result:
print ("Incorrect. The right answer is {}".format(correct_result))
return False
else:
print("Correct!")
return True
username = input("What is your name? ")
print("Hi {}! Welcome to the Arithmetic quiz...".format(username))
class_name = input("Are you in class 1, 2 or 3? ")
correct_answers = 0
num_questions = 10
for i in range(num_questions):
if test():
correct_answers +=1
print("{}: You got {}/{} questions correct.".format(
username,
correct_answers,
num_questions,
))
class_name = class_name + ".txt" #creates a txt file called the class that the user entered earlier on in the quiz.
file = open(class_name , 'a') #These few lines open and then write the username and the marks of the student into the txt file.
name = (username)
file.write(str(username + " : " ))
file.write(str(correct_answers))
file.write('\n') #This puts each different entry on a different line.
file.close() #This closes the file once the infrmation has been written.

A much better solution would be to store the data in a different format that made everything easy. For example, if you used a shelve database that mapped each username to a deque of answers, the whole thing would be this simple:
with shelve.open(class_name) as db:
answers = db.get(username, collections.deque(maxlen=3))
answers.append(correct_answers)
db[username] = answers
But if you can't change the data format, and you need to just append new lines to the end of a human-readable text file, then the only want to find out if there are already 3 answers is to read through every line in the file to see how many are already there. For example:
past_answers = []
with open(class_name) as f:
for i, line in enumerate(f):
# rsplit(…,1) instead of split so users who call
# themselves 'I Rock : 99999' can't cheat the system
name, answers = line.rsplit(' : ', 1)
if name == username:
past_answers.append(i)
And if there were 3 past answers, you have to rewrite the file, skipping line #i. This is the really fun part; text files aren't random-access-editable, so the best you can do is either read it all into memory and write it back out, or copy it all to a temporary file and move it over the original. Like this:
excess_answers = set(past_answers[:-2])
if excess_answers:
with open(class_name) as fin, tempfile.NamedTemporaryFile() as fout:
for i, line in enumerate(fin):
if i not in excess_answers:
fout.write(line)
os.replace(fout.name, fin)
That part is untested. And it requires Python 3.3+; if you have an earlier version and are on Mac or Linux you can just use os.rename instead of replace, but if you're on Windows… you need to do some research, because it's ugly and no fun.
And now, you can finally just append the new answer, as you're already doing.

Related

How do I get a python quiz to randomize questions?

My task is to make a quiz using python, with questions being stored in an external file. However, I can not figure out how to get my questions to randomize and only display 10 at a time out of the 20 possible
I have tried using import random however the syntax random.shuffle(question) does not seem to be valid. I am not sure what to do now.
The question.txt file is laid out as:
Category
Question
Answer
Answer
Answer
Answer
Correct Answer
Explanation
My code:
#allows program to know how file should be read
def open_file(file_name, mode):
"""Open a file."""
try:
the_file = open(file_name, mode)
except IOError as e:
print("Unable to open the file", file_name, "Ending program.\n", e)
input("\n\nPress the enter key to exit.")
sys.exit()
else:
return the_file
def next_line(the_file):
"""Return next line from the trivia file, formatted."""
line = the_file.readline()
line = line.replace("/", "\n")
return line
#defines block of data
def next_block(the_file):
"""Return the next block of data from the trivia file."""
category = next_line(the_file)
question = next_line(the_file)
answers = []
for i in range(4):
answers.append(next_line(the_file))
correct = next_line(the_file)
if correct:
correct = correct[0]
explanation = next_line(the_file)
time.sleep(1.5)
#beginning of quiz questions
def main():
trivia_file = open_file("trivia.txt", "r")
title = next_line(trivia_file)
welcome(title)
score = 0
# get first block
category, question, answers, correct, explanation = next_block(trivia_file)
while category:
# ask a question
print(category)
print(question)
for i in range(4):
print("\t", i + 1, "-", answers[i])
# get answer
answer = input("What's your answer?: ")
# check answer
if answer == correct:
print("\nCorrect!", end=" ")
score += 1
else:
print("\nWrong.", end=" ")
print(explanation)
print("Score:", score, "\n\n")
# get next block
category, question, answers, correct, explanation = next_block(trivia_file)
trivia_file.close()
print("That was the last question!")
print("Your final score is", score)
main()
That is most of the code associated with the program. I will be very grateful for any support available.
You can read the file and group its contents into blocks of eight. To generate unique random questions, you can use random.shuffle and then list slicing to create the groups of questions. Also, it is cleaner to use a collections.namedtuple to form the attributes of the question for use later:
import random, collections
data = [i.strip('\n') for i in open('filename.txt')]
questions = [data[i:i+8] for i in range(0, len(data), 8)]
random.shuffle(questions)
question = collections.namedtuple('question', ['category', 'question', 'answers', 'correct', 'explanation'])
final_questions = [question(*i[:2], i[2:6], *i[6:]) for i in questions]
Now, to create the groups of 10:
group_questions = [final_questions[i:i+10] for i in range(0, len(final_questions), 10)]
The result will be a list of lists containing the namedtuple objects:
[[question(category='Category', question='Question', answers=['Answer', 'Answer', 'Answer', 'Answer'], correct='Correct Answer', explanation='Explanation ')]]
To get the desired values from each namedtuple, you can lookup the attributes:
category, question = question.category, question.question
Etc.

Python Iteration Mess

As you can see below I am trying to make a program that takes a file called names.txt, breaks it down into a list with .split('/n'), then adds a password for each user in the list. For some reason the for look treats the list as if it were a string, so instead of treating it like:
Bob
Charley
Ron
It breaks it down like:
B
o
b
C
h
....
Thus giving each letter a password instead of the list itself.
What am I doing wrong?
Is there a way I can test to see what the for loop is actually being given?
I have been playing with it to see if it were being given a string, but the list appears to be clealy a list when printed, so why would it be getting treated like a string in the for loop?
def importNames():
try:
file = open("names.txt", "r")
contents = file.read()
print(contents)
file.close()
return contents
except:
print("The file was not found.")
print("Make sure you have a file called \"names.txt\" in the working directory (where you ran this program)")
exit()
def createPasswordList(nameList):
print("They are being given the standard password of \"p#ssw0rd.\"")
#nameList = ["Pickles", "Bob's", 'wow zers john'] #This is for testing purposes. It works just fine, but the original nameList breaks down badly.
passList = []
#for x, value in enumerate(nameList):
for i in nameList:
print(i)
passList.append("p#ssw0rd")
print(passList)
return passList
def createUsers(nameList, passwordList): #takes in a list of usernames, then adds creates them.
for i in nameList:
print("This will do something soon.")
#encPass = crypt.crypt(passwordList[i],"22") #22 is a salt number, use crypt per useradd manual
#os.system("useradd -p " + encPass + " " + nameList[i]) #useradd -p encryptedpass username
def convertNamesToList(originalList):
print("Converting names.") #Use newline as a delimiter
newList = originalList.split('\n')
print(newList)
return newList
def convertNameToUsernames(originalNames):
print("Creating usernames")
print("This program is used to make some users.")
print("If you import a file, have it in the working directory called \"names.txt\".")
print("Would you like to import names or add them manually? (n/m)")
answer = input()
if (answer is 'm' or answer is 'M'):
createUser()
print("The user gets created. Good job.")
else:
originalNames = importNames() #this will return a string of the file.
convertNamesToList(originalNames) #convert the string to sets of names. Use newlines as delimiters.
#convert the names to usernames
print("Do the users have passwords? (y/n)")
#answer = input()
answer = 'n' ###FORCE###
if (answer is 'n' or answer is 'N'):
passwordList = createPasswordList(originalNames)
You're never doing anything with the return value from convertNamesToList. You don't store it anywhere. Then you pass originalNames, which is a string (you even indicate this in a comment) to createPasswordList.
I think you want something like:
originalNames = importNames() #this will return a string of the file.
listOfNames = convertNamesToList(originalNames) #convert the string to sets of names. Use newlines as delimiters.
#convert the names to usernames
print("Do the users have passwords? (y/n)")
#answer = input()
answer = 'n' ###FORCE###
if (answer is 'n' or answer is 'N'):
passwordList = createPasswordList(listOfNames)
It looks like your nameList is actually a string. Assuming that you have one name per line of the names.txt file, Try this:
def importNames():
try:
file = open("names.txt", "r")
contents=[]
for line in file.read():
contents.append(line)
print(contents)
file.close()
return contents
You then no not need to convert it to a list later.

Trying to load and edit a pickled dictionary, getting an EOFError

I'm trying to modify a trivia program found in a book as part of a tutorial; I need to save the name and score of the player using a pickled dictionary. I've already created the dat file using a separate program, to avoid reading from a file that doesn't exist.
This is the code for the trivia program.
#Trivia Challenge
#Trivia game that reads a plain text file
import sys
def open_file(file_name, mode):
"""Open a file"""
try:
the_file = open(file_name, mode)
except IOError as e:
print("Unable to open the file", file_name, "Ending program.\n", e)
input("\n\nPress the enter key to exit.")
sys.exit()
else:
return the_file
def next_line(the_file):
"""Return next line from the trivia file, formatted."""
line = the_file.readline()
line = line.replace("/", "\n")
return line
def next_block(the_file):
"""Return the next block of data from the triva file."""
category = next_line(the_file)
question = next_line(the_file)
answers = []
for i in range(4):
answers.append(next_line(the_file))
correct = next_line(the_file)
if correct:
correct = correct[0]
explanation = next_line(the_file)
value = next_line(the_file)
return category, question, answers, correct, explanation, value
def welcome(title):
"""Welcome the player and get his or her name."""
print("\t\tWelcome to Trivia Challenge!\n")
print("\t\t", title, "\n")
def saving(player_name):
import pickle
f = open("trivia_scores.dat", "rb+")
highscores = pickle.load(f)
if player_name in highscores and score > highscores[player_name]:
highscores[player_name] = score
pickle.dump(highscores, f)
elif player_name not in highscores:
highscores[player_name] = score
pickle.dump(highscores, f)
print("The current high scores are as follows:")
print(highscores)
f.close()
def main():
trivia_file = open_file("trivia.txt", "r")
title = next_line(trivia_file)
welcome(title)
score = 0
#Get the first block
category, question, answers, correct, explanation, value = next_block(trivia_file)
while category:
#Ask a question
print(category)
print(question)
for i in range(4):
print("\t", i + 1, "-", answers[i])
#Get answer
answer = input("What is your answer?: ")
#Check answer
if answer == correct:
print("\nRight!", end=" ")
score += int(value)
else:
print("\nWrong!", end=" ")
print(explanation)
print("Score:", score, "\n\n")
#Get the next block
category, question, answers, correct, explanation, value = next_block(trivia_file)
trivia_file.close()
print("That was the last question!")
print("Your final score is", score)
return score
player_name = input("First, enter your name: ")
main()
saving(player_name)
input("\n\nPress the enter key to exit.")
The eponymous error occurs at this point:
def saving(player_name):
import pickle
f = open("trivia_scores.dat", "rb+")
highscores = pickle.load(f)
When the questions end, the program attempts to run the "saving" module, which (In theory) opens the trivia_scores.dat file, loads the highscores dictionary, checks to see if the player's name is in the dictionary, and if their current score is higher than the one in the file, it overwrites it.
But for some reason, when the program attempts to load the highscores dictionary, instead I get this error message.
EOFError: Ran out of input
I have never seen this error before. From some cursory googling, I got the impression that it has something to do with the program trying to read from an empty file. But that made no sense to me, since I specifically created a dat file using a different program to prevent that from happening: trivia_scores.dat is NOT an empty file. I even read from it with Python Shell to make sure.
What does this error mean, and why won't Python load the dat file?
Context: The book I'm reading from is Python for the Absolute Beginner, by Michael Dawson. This program and the challenge I'm trying to complete come from chapter 7. The program was running fine before I added the saving module.
Probably the original trivia_scores.dat file you wrote got corrupt (maybe you didn't call close() on it?). You should try creating a new file and adding a pre-populated dictionary to this file. Then try reading from this new file.

File Writing Python, How to print variable to txt file

I am trying to print a variable of a score and name to a .txt file using python.
import random
import csv
import operator
import datetime
now = datetime.datetime.now() ## gets the exact time of when the user begins the test.
def main():
global myRecord
myRecord = []
name = getNames()
myRecord.append(name)
record = quiz()
def getNames(): ## this function grabs first and lastname of the user
firstName = input ("Please enter your first name") ## asks for users name
surName = input("Please enter your surname") ## asks for users suername
space = " "
fullName = firstName + space +surName ## puts data of name together to make full name
print("Hello")
print (fullName)
myRecord.append(fullName)
return fullName ## this is a variable returned to main
def quiz():
print('Welcome. This is a 10 question math quiz\n')
score = 0 ## sets score to 0.
for i in range(10): ## repeats question 10 times
correct = askQuestion()## if the statement above if correct the program asks a question.
if correct:
score += 1## adds one to the score
print('Correct!\n')## prints correct if the user gets a question correct.
else:
print('Incorrect!\n') ## prints incorrect if the user gets a question wrong.
return 'Your score was {}/10'.format(score)
def randomCalc():
ops = {'+':operator.add, ## selects one of the three operators
'-':operator.sub, ## selects one of the three operators
'*':operator.mul,} ## selects one of the three operators
num1 = random.randint(0,12) ## samples a number between 0 and 12
num2 = random.randint(1,10) ## zero are not used to stop diving by zero
op = random.choice(list(ops.keys()))
answer = ops.get(op)(num1,num2)
print('What is {} {} {}?\n'.format(num1, op, num2)) ## puts together the num1, the operator and num2 to form question
return answer
def askQuestion():
answer = randomCalc()
guess = float(input())
return guess == answer
def myfileWrite (myrecord):
with open('Namescore.txt', 'w') as score:
score.write(fullName + '\n')
main()
here is the full code it should ask the users name, print 10 maths questions and then save the time name and score to a txt file
if you can help please do
many thanks
Your indentation is incorrect and you never actually call the function:
with open('Namescore.txt', 'w') as score:
score.write(fullName + '\n')
the code you wrote would IIRC re-make the file each time you ran the code. I believe this is the correct way to do it:
with open("Namescore.txt", "a") as file:
file.write(name, score, "\n") # I don't know what your vars are called
This will append to the file rather than rewrite :)
If you want to do it your way, the correct way would be:
def writeScore(name, score):
file = open("Namescore.txt", "a")
file.write(name, score, "\n")
file.close()
writeScore("Example Examlpus", 201)

Writing multiple lines to file and then reading them with Python

I've just undertaken my first proper project with Python, a code snippet storing program.
To do this I need to first write, then read, multiple lines to a .txt file. I've done quite a bit of googling and found a few things about writing to the file (which didn't really work). What I have currently got working is a function that reads each line of a multiline input and writes it into a list before writing it into a file. I had thought that I would just be able to read that from the text file and add each line into a list then print each line separately using a while loop, which unfortunately didn't work.
After going and doing more research I decided to ask here. This is the code I have currently:
'''
Project created to store useful code snippets, prehaps one day it will evolve
into something goregous, but, for now it's just a simple archiver/library
'''
#!/usr/local/bin/python
import sys, os, curses
os.system("clear")
Menu ="""
#----------- Main Menu ---------#
# 1. Create or edit a snippet #
# 2. Read a snippet #
# 0. Quit #
#-------------------------------#
\n
"""
CreateMenu ="""
#-------------- Creation and deletion --------------#
# 1. Create a snippet #
# 2. Edit a snippet #
# 3. Delete a snippet (Will ask for validation) #
# 0. Go back #
#---------------------------------------------------#
\n
"""
ReadMenu="""
#------ Read a snippet ------#
# 1. Enter Snippet name #
# 2. List alphabetically #
# 3. Extra #
# 0. Go Back #
#----------------------------#
"""
def readFileLoop(usrChoice, directory):
count = 0
if usrChoice == 'y' or 'n':
if usrChoice == 'y':
f = open(directory, 'r')
text = f.read()
f.close()
length = len(text)
print text
print length
raw_input('Enter to continue')
readMenu()
f.close()
elif choice == 'n':
readMenu()
def raw_lines(prompt=''):
result = []
getmore = True
while getmore:
line = raw_input(prompt)
if len(line) > 0:
result.append(line)
else:
getmore = False
result = str(result)
result.replace('[','').replace(']','')
return result
def mainMenu():
os.system("clear")
print Menu
choice = ''
choice = raw_input('--: ')
createLoop = True
if choice == '1':
return creationMenu()
elif choice == '2':
readMenu()
elif choice == '0':
os.system("clear")
sys.exit(0)
def create():
os.system("clear")
name = raw_input("Enter the file name: ")
dire = ('shelf/'+name+'.txt')
if os.path.exists(dire):
while os.path.exists(dire):
os.system("clear")
print("This snippet already exists")
name = raw_input("Enter a different name: ")
dire = ('shelf/'+name+'.txt')
print("File created\n")
f = open(dire, "w")
print("---------Paste code below---------\n")
text = raw_lines()
raw_input('\nEnter to write to file')
f.writelines(text)
f.close()
raw_input('\nSnippet successfully filled, enter to continue')
else:
print("File created")
f = open(dire, "w")
print("---------Paste code below---------\n")
text = raw_lines()
print text
raw_input('\nEnter to write to file')
f.writelines(text)
f.close()
raw_input('\nSnippet successfully filled, enter to continue')
def readMenu():
os.system("clear")
name = ''
dire = ''
print ReadMenu
choice = raw_input('--:')
if choice == '1':
os.system("clear")
name = raw_input ('Enter Snippet name: ')
dire = ('shelf/'+name+'.txt')
if os.path.exists(dire):
choice = ''
choice = raw_input('The Snippet exists! Open? (y/n)')
'''if not choice == 'y' or 'n':
while (choice != 'y') or (choice != 'n'):
choice = raw_input('Enter \'y\' or \'n\' to continue: ')
if choice == 'y' or 'n':
break'''
readFileLoop(choice, dire)
else:
raw_input('No snippet with that name exists. Enter to continue: ') #add options to retry, create snippet or go back
readMenu()
elif choice == '0':
os.system("clear")
print Menu
def creationMenu(): ###### Menu to create, edit and delete a snippet ######
os.system("clear")
print CreateMenu
choice = raw_input('--: ')
if choice == '1': ### Create a snippet
os.system("clear")
print create()
print creationMenu()
elif choice == '2':
os.system("clear") ### Edit a snippet
print ("teh editon staton")
raw_input()
print creationMenu()
elif choice == '3':
os.system("clear") ### Delete a snippet
print ("Deletion staton")
raw_input()
print creationMenu()
elif choice == '0': ### Go Back
os.system("clear")
######## Main loop #######
running = True
print ('Welcome to the code library, please don\'t disturb other readers!\n\n')
while running:
mainMenu()
######## Main loop #######
Tl;Dr: Need to write and read multiline text files
The problem that I'm having is the way the multilines are being stored to the file, it's stored in list format e.g ['line1', 'line2', 'line3'] which is making it difficult to read as multilines because I can't get it to be read as a list, when I tried it added the whole stored string into one list item. I don't know if I'm writing to the file correctly.
OK, so the problem is with writing the file. You're reading it in correctly, it just doesn't have the data you want. And the problem is in your raw_lines function. First it assembles a list of lines in the result variable, which is good. Then it does this:
result = str(result)
result.replace('[','').replace(']','')
There are two small problems and one big one here.
First, replace:
Return[s] a copy of the string with all occurrences of substring old replaced by new.
Python strings are immutable. None of their methods change them in-place; all of them return a new string instead. You're not doing anything with that new string, so that line has no effect.
Second, if you want to join a sequence of strings into a string, you don't do that by calling str on the sequence and then trying to parse it. That's what the join method is for. For example, if your lines already end with newlines, you want ''.join(result). If not, you want something like '\n'.join(result) + '\n'. What you're doing has all kinds of problems—you forgot to remove the extra commas, you will remove any brackets (or commas, once you fix that) within the strings themselves, etc.
Finally, you shouldn't be doing this in the first place. You want to return something that can be passed to writelines, which:
Write[s] a sequence of strings to the file. The sequence can be any iterable object producing strings, typically a list of strings.
You have a list of strings, which is exactly what writelines wants. Don't try to join them up into one string. If you do, it will run, but it won't do the right thing (because a string is, itself, a sequence of 1-character strings).
So, if you just remove those two lines entirely, your code will almost work.
But there's one last problem: raw_input:
… reads a line from input, converts it to a string (stripping a trailing newline), and returns that.
But writelines:
… does not add line separators.
So, you'll end up with all of your lines concatenated together. You need the newlines, but raw_input throws them away. So, you have to add them back on. You can fix this with a simple one-line change:
result.append(line + '\n')
To read multiple lines from a file, it's easiest to use readlines(), which will return a list of all lines in the file. To read the file use:
with open(directory, 'r') as f:
lines = f.readlines()
And to write out your changes, use:
with open(directory, 'w') as f:
f.writelines(lines)
fileList = [line for line in open("file.txt")]
While the previously mention idiom will work for reading files, I like mine. Its short and to the point.

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