Tuple

t = ([10, 12], "math", 2022.01.01T09:10:01, 97c, 22l, 3.5f)
type(t)

Output: tuple

1. Access a tuple item by referring to the position.

   t[3]

   Output: 'a'

   t[-2]

   Output: 22

2. Access tuple items by slicing. Note that the step parameter cannot be specified in Python Parser.

   t[0:4]

   Output: ([10, 12], 'math', 2022.01.01T09:10:01, a)

   t[4:]

   Output: (22, 3.5)

A tuple is an immutable sequence whose items cannot be changed, removed, or added. It is infeasible to update a tuple directly through indices. However, you can modify the mutable sequences in a tuple by assigning the mutable sequence to a new variable and updating the value of this variable.

tmp = t[0]
tmp[0]=1
t
// not support: t[0][0]=1

Output: ([1, 12], 'math', 2022.01.01T09:10:01, a, 22, 3.5)

dir(s)

Output: ['__add__', '__at__', '__dir__', '__eq__', '__iadd__', '__imultiply__', '__init__', '__iter__', '__len__', '__multiply__', '__ne__', '__repr__', '__req__', '__rne__', '__str__', 'toddb']

toddb is a unique method in Python Parser, which supports converting a Python Parser tuple into a DolphinDB tuple.

s = (1, 2, 3)
type(s.toddb())

Output: dolphindb.VECTOR.ANY