Tuples

https://docs.python.org/3/library/stdtypes.html#tuples

INTRODUCTION

Tuples are immutable heterogeneous sequences.

+----------------------+----------------------------+
| Operation            | Meaning                    |
+----------------------+----------------------------+
| T = () ; T = tuple() | empty tuple                |
| T = (0,)             | one item                   |
| T = tuple([0])       | one item (from list)       |
| T = (1, 3, 5, 7)     | four items                 |
| T = tuple(iterable)  | make tuple from iterable   |
| len(T)               | length                     |
| T1 + T2              | concatenation              |
| T * n, n * T         | repetition                 |
| T[i]                 | get item at index          |
| T[i:j]               | slice of T (new tuple)     |
| T[i:j:k]             | slice of T (new tuple)     |
| for item in T: pass  | iteration                  |
| item in T            | containing (linear-time)   |
| item not in T        | containing (linear-time)   |
| T.index(item)        | first occurrence           |
| T.count(item)        | number of occurrences      |
| max(T), min(T)       | the largest|smallest item  |
| del T                | remove the name T          |
| (x, y) = (a, b)      | x = a ; y = b # assignment |
+----------------------+----------------------------+

# help(tuple)
T = (3, 5, 7)
#T[1] = 9   # TypeError
#T.append(9)   # AttributeError
tuple([1, 3, 5])   # (1, 3, 5)
tuple("abc")   # ("a", "b", "c")

x, y = [1, 2]   # x = 1 ; y = 2
x, y = "ab"   # x = "a" ; y = "b"
x, y = y, x   # exchanging references, x = "b", y = "a"