[Tutor] help with random.randint

[Benno Lang]

On Wed, Feb 3, 2010 at 12:21 PM, David <ldl08 at gmx.net> wrote:
> Hello list,
>
> I thought this was easy even for me, but I was wrong, I guess.
> Here is what I want to do: take two random numbers between 1 and 99, and put
> them into a list.
>
> import random
> terms =  []
> for i in range(2):
>        terms = random.randint(1, 99)

All you're doing here is assigning an integer value to 'terms', twice.
This assignment means 'terms' is no longer a list, but is now just an
int. What you want is probably:
terms.append (random.randint(1, 99))

> So I tried to change line 4 to the following:
>        terms += random.randint(1, 99)

You can't freely mix types with python operators, i.e. a_list += an_int
But you can use += with 2 ints or 2 lists, so you could do:
terms += [random.randint(1, 99)]
I think using append is much nicer though.

> I understand this error thus: once an int has been placed into the list
> terms, no further int can be added. But: terms is a mutable list, and NOT an
> 'int' object!

The int was never added to the list in the first place, because list
+= int is not something Python understands.

> So here are my questions: what is the problem, and how can I generate two
> random numbers and store them (preferably in a tuple)?

I hope what I wrote above answers the first question.
IIRC tuples are immutable, so you either to create the list first and
then convert it to a tuple:
terms_tuple = tuple(terms)

Or you can create a tuple from the beginning (without a loop):
terms_tuple = (random.randint(1, 99), random.randint(1, 99))

HTH,
benno