On Friday, February 14, 2014 11:26:13 AM UTC-7, Jussi Piitulainen wrote: > dave em writes: > > > > > He is asking a question I am having trouble answering which is how a > > > variable containing a value differs from a variable containing a > > > list or more specifically a list reference. > > > > My quite serious answer is: not at all. In particular, a list is a > > value. > > > > All those pointers to references to locations are implementation > > details. The user of the language needs to understand that an object > > keeps its identity when it's passed around: passed as an argument, > > returned by a function, stored in whatever location, retrieved from > > whatever location.
Jessi, Thanks for your quick response. I'm still not sure we understand. The code below illustrates the concept we are trying to understand. Case 1: Example of variable with a specific value from P 170 of IYOCGWP >>> spam = 42 >>> cheese = spam >>> spam = 100 >>> spam 100 >>> cheese 42 Case 2: Example of variable with a list reference from p 170 >>> spam = [0, 1, 2, 3, 4, 5] >>> cheese = spam >>> cheese[1] = 'Hello!' >>> spam [0, 'Hello!', 2, 3, 4, 5] >>> cheese [0, 'Hello!', 2, 3, 4, 5] What I am trying to explain is this, why in case 1 when acting on spam (changing the value from 42 to 100) only affects spam and not cheese. Meanwhile, in case two acting on cheese also affects spam. Thanks and v/r, Dave -- https://mail.python.org/mailman/listinfo/python-list
