Python 3.3.3 (v3.3.3:c3896275c0f6, Nov 16 2013, 23:39:35) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART ================================
>>> 
# running the function convert_base()
>>> help(convert_base)
Help on function convert_base in module __main__:

convert_base(n, b)
    convert_base(int,int) -> str
    returns the str representation of n (decimal)  in base 2<=b<=36
>>> convert_base(10,2)
'1010'
# the initial version of the function could not handle the following case
>>> convert_base(10,16)
'10'
>>> ================================ RESTART ================================
# the improved version restricts the range of b
>>> convert_base_imp(10,100)
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    convert_base_imp(10,100)
  File "/Users/Yael/Dropbox/cs1001/week3/4class/0a_convert_base.py", line 7, in convert_base_imp
    assert 2<=b<=36
AssertionError
>>> convert_base_imp(10,16)
'a'
# python has a built-in function for converting decimal to binary
>>> bin(12)
'0b1100'
>>> bin(12)[2:]
'1100'
# python has a built-in function for converting a string which represents a number in a specified base to decimal
>>> int("1100",2)
12
>>> int("1100",10)
1100
# motivating examples for studying python's memory model
# a
>>> def change_int(num):
	num=999
>>> n = 1
>>> n
1
>>> change_int(n)
>>> n
1
# b
>>> def add_to_list(lst):
	lst.append(999)

	
>>> l = [1,2,3]
>>> add_to_list(l)
>>> l
[1, 2, 3, 999]
# c
>>> def change_list(lst):
	lst = [999,999,999]
>>> l = [1,2,3]
>>> change_list(l)
>>> l
[1, 2, 3]