is there a difference between one line and many lines

[vino19]

Hello, I'm a newbie.
What's the defference between

>>>a=-6; b=-6; a is b
>>>True

and

>>>a=-6
>>>b=-6
>>>a is b
>>>False

?
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Re: is there a difference between one line and many lines

[vino19]

Sure, I understand that "is" is not "==", cause "is" just compares id(a)==id(b).

I have a win32 CPython and the range of "singletons" is from -5 to 256 on my 
machine. 

I am asking about what happens in Python interpreter? Why is there a difference 
between running one line like "a=1;b=1" and two lines like "a=1 \n b=1"? Does 
it decide to locate memory in different types depend on a code?

Thanks
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Re: is there a difference between one line and many lines

[vino19]

Python 2.7.1 (downloaded from python.org a week ago)

You see, if I save this to a file and then run from CMD: "python test1.py" the 
result will be the same: "True"

When I use IDLE or IPython or DreamPie or maybe something else then result is 
not the same. So maybe as Chris Angelico said it is the IDLE(or Ipython) makes 
some optimization depend on a code style. 
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searching in list

[vino19]

I want to make a function that is called only once per one argument. I mean I 
want to store data of function calling to prevent calling it again if there is 
no need.
How to make it? For example I can make a global list that just consist of 
tuples 
[(arg1, res1), (arg2, res2), ...]. Ok, how to search if an arg135 in that list?

Thanks for answering
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Re: searching in list

[vino19]

Thanks.

It seems that dictionary is a sorted list of tuples, so the procedure of 
searching an element is quite quick.
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