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Re: Can tuples be replaced with lists all the time?

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On 2014-02-23, Sam <lightaiyee@gmail.com> wrote:

> My understanding of Python tuples is that they are like immutable
> lists. If this is the cause, why can't we replace tuples with lists
> all the time (just don't reassign the lists)? Correct me if I am
> wrong.

In addition to the things related to one being mutable and the other
immutable, there is a certain tradition that often results in differnt
usages for them. 

Though it's certainly not required, lists are more often used as
variable length _homogeneous_ containers -- sort of like a variable
length array or linked list in C.  The "type" or "meaning" of element
#N is the same as that of element #M.

In constrast, tuples are often used as fixed-length heterogenous
containers (more like a struct in C except the fields are named 0, 1,
2, 3, etc.).  In a particular context, the Nth element of a tuple will
always mean one thing (e.g. a person's last name) while the Mth
element will always be something else (e.g. a person's age).

-- 
Grant

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Thread

Can tuples be replaced with lists all the time? Sam <lightaiyee@gmail.com> - 2014-02-22 20:06 -0800
  Re: Can tuples be replaced with lists all the time? Paul Rubin <no.email@nospam.invalid> - 2014-02-22 20:28 -0800
  Re: Can tuples be replaced with lists all the time? Chris Angelico <rosuav@gmail.com> - 2014-02-23 15:18 +1100
  Re: Can tuples be replaced with lists all the time? Ben Finney <ben+python@benfinney.id.au> - 2014-02-23 15:49 +1100
  Re: Can tuples be replaced with lists all the time? 88888 Dihedral <dihedral88888@gmail.com> - 2014-02-23 11:45 -0800
  Re: Can tuples be replaced with lists all the time? Roy Smith <roy@panix.com> - 2014-02-22 23:19 -0500
    Re: Can tuples be replaced with lists all the time? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-03-02 17:21 -0500
  Re: Can tuples be replaced with lists all the time? Grant Edwards <invalid@invalid.invalid> - 2014-02-23 17:07 +0000
    Re: Can tuples be replaced with lists all the time? Roy Smith <roy@panix.com> - 2014-02-23 12:48 -0500
      Re: Can tuples be replaced with lists all the time? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-03-01 21:20 +0000
      Re: Can tuples be replaced with lists all the time? Terry Reedy <tjreedy@udel.edu> - 2014-03-01 18:15 -0500

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