python random in lists

Question

This is my current code:

import random

while True:
    try:
        num   = int(input("Enter the total number of digits you want to generate:"))
        upper = int(input("Enter your highest number:"))
        lower = int(input("Enter your lowest number:"))

        if upper < 1 or lower < 1 or upper <= lower:
            print ("Sorry, invalid. Make sure your upper bound is higher than lower bound, make sure all numbers are integers greater than 0.")
            continue

        if num < 1:
            print ("Sorry, invalid. Try again.")
            continue

        **mylist = [0] * num
        for x in range (lower, upper):**

The part directly above here is the part that I am not quite sure how to go forward on. I want to generate random numbers depending on the number the user enters and within the upper and lower bounds that the user enters into a list that displays here. Can someone guide me through this? thank you!

except:
    print ("Sorry, invalid. Try again.")

else:
    print ("Thank you.")
    break

num, upper, and lower are either redundant or conflicting.

President James K. Polk
– President James K. Polk

2012-12-11 00:49:26 +00:00
Commented Dec 11, 2012 at 0:49 — President James K. Polk
– President James K. Polk, Commented Dec 11, 2012 at 0:49

mVChr · Accepted Answer · 2012-12-11 00:43:39Z

2

If you replace your ** lines with the following, using random.randint(lower, upper), you'll display the list you want:

mylist = []
for _ in range(num):
    mylist.append(random.randint(lower, upper))

print mylist

You could also do this with a list comprehension:

mylist = [random.randint(lower, upper) for _ in range(num)]
print mylist

answered Dec 11, 2012 at 0:43

mVChr

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2 Comments

user1762229 Over a year ago

thank you @mvchr, is there a way write the first code so that the same number does not repeat in the list more than once

mVChr Over a year ago

@user1762229 see Brenden Brown's answer

Lars · Accepted Answer · 2012-12-11 00:48:57Z

1

you probably need:

print [random.randint(lower, upper) for n in range(num)]

which displays a list of num random integers with minimum lower and maximum upper (inclusive).

answered Dec 11, 2012 at 0:48

Lars

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Comments

Kartik · Accepted Answer · 2012-12-11 00:43:56Z

0

You can use the randint to generate numbers in the given range.

Return a random integer x such that a <= x <= b.

import random
print random.randint(a, b)

So to generate N numbers in the range a and b

numbers = [random.randint(a, b) for i in range(N)]
print numbers

edited Dec 11, 2012 at 0:43

answered Dec 11, 2012 at 0:38

Kartik

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1 Comment

gmlobdell Over a year ago

look at the random library. Don't forget to use random.seed().

Brenden Brown · Accepted Answer · 2012-12-11 00:59:14Z

0

If you wanted a random subset of the numbers between lower and upper, inclusive, you could use:

random.sample(num, xrange(lower, upper + 1))

http://docs.python.org/2/library/random.html#random.sample

But I think you wanted duplicates to be possible, in which case use one of the other answers.

edited Dec 11, 2012 at 0:59

answered Dec 11, 2012 at 0:36

Brenden Brown

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3 Comments

James Waldby - jwpat7 Over a year ago

That will generate num numbers, instead of num digits of random numbers. (The question may be badly worded, on this point.)

gmlobdell Over a year ago

This generates a sequence with no repeats from the population. What if num is greater than upper-lower?

Lars Over a year ago

sampe gives unique numbers, no repeats, you probably need: print [random.randint(lower, upper) for n in range(num)] which displays a list of num random integer numbers with minimum lower and maximum upper (inclusive).

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