Python short course: Tuples in Action
Python tuple is a collectio type. Tuples are immutable (cannot be changed in place). The tuple is similar but different from the list.
Basic operation
In [1]: (1, 2) + (3, 4)
Out[1]: (1, 2, 3, 4)
In [2]: (1, 2) * 4
Out[2]: (1, 2, 1, 2, 1, 2, 1, 2)
In [3]: T = (1, 2, 3, 4)
In [4]: T[0], T[1:3]
Out[4]: (1, (2, 3))
A tuple is immutable, but a list can change its element
In [5]: T = (1., [2, 3], 4)
In [6]: T[0]
Out[6]: 1.0
In [7]: T[0] = 5
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-7-0e6a27ccfe54> in <module>
----> 1 T[0] = 5
TypeError: 'tuple' object does not support item assignment
In [8]: T[1][0] = 'changed'
In [9]: T
Out[9]: (1.0, ['changed', 3], 4)
Reference:
Lutz, M. Learning Python (5th ed.) O'Reilly, 2013, 1594
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