Python code to guess a number produces same number twice or thrice when close

Question

I am new to python, sorry about a basic one.

The code works fine but it guesses same number twice or maybe more number of times. I want to guess an unique number every time.

import random

print("Hey human guess a number between 1 to 50 and i will try guessing what it is ! \n ")
input("Press enter when you have done the first step \n")
print("after my guess if its correct then hit y, if i need to guess higher than hit g and if i need to guess lower then hit l\n")

answer = ""
m = 1
n = 50

while(answer!='y'):

    guess = random.randint(m,n)
    print(guess)
    reply = input("Is my guess correct ?")

    if reply  ==  'y':
        print("GG")
        answer  = 'y'

    elif reply  ==  'l':
        n = guess
        print("\n Okay let me try again")

    elif reply  ==  'g':
        m = guess
        print("\n aaah let me try again please \n")

    else:
        print("\n Seriously man what did i tell you before ?")

Thank you in advance.

score 1 · Accepted Answer · answered Jan 15 '17 at 13:26

1

As stated in the docstring of random.randint, this method "returns a random integer in range [a, b], including both end points". That means that when you assign the guess to either m or n the guess is going to be included for the range of the random.

Thus, to fix your code you could modify the following lines:

m = 0
n = 51

guess = random.randint(m+1,n-1)

In this way, you never include the guess in the range of the random. Hope this helps.

answered Jan 15 '17 at 13:26

José Sánchez

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Glad to hear it helped! Do you mind then accepting the answer? :) – José Sánchez Jan 15 '17 at 13:32

score 0 · Answer 2 · answered Jan 15 '17 at 13:31

0

Create a list of guessed numbers guessed_numbers = []

Then whenever save the guess guessed_numbers.append(guess)

And before setting guess, check that guess is not in guessed numbers.

So you wind up with:

n = 50
guessed_numbers = []

while (answer != 'y'):

    guess = random.randint(m, n)
    while (guess in guessed_numbers):
        guess = random.randint(m, n)
    guessed_numbers.append(guess)
    print(guess)

answered Jan 15 '17 at 13:31

Anthony Manning-Franklin

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A set would be much better suited for this. – miradulo Jan 15 '17 at 13:51
On my phone, but I thought the point of sets were that they're immutable, thus no append method? – Anthony Manning-Franklin Jan 15 '17 at 13:52
1

You are mistaken, and probably thinking of a tuple. [See this maybe](http://stackoverflow.com/questions/2831212/python-sets-vs-lists). – miradulo Jan 15 '17 at 13:54

score -1 · Answer 3 · answered Jan 15 '17 at 13:24

The problem is likely that random.randint produces a number between m and n inclusive. If the range is 1-50, and the program guesses 50, it sets the upper bound to 50 again, which means it could guess that number twice. It will be more likely to happen as the range narrows.

I think if you change the line

n=guess

to read

n=guess-1

and similarly add one for m when it guesses too low, you'll get the result you're looking for.

Python code to guess a number produces same number twice or thrice when close

3 Answers3