otp.param#

class OnetickParameter(name, dtype, string_literal=True)#

Bases: onetick.py.core.column_operations.base.Operation

Data type representing OneTick parameter.

This object can be used in all places where Operation can be used and also in some additional places, e.g. some functions’ parameters.

Parameters

  • name (str) – The name of the parameter.

  • dtype – The type of the parameter.

  • string_literal (bool) –

    By default, OneTick inserts string parameters as is in the graph, and they are interpreted as an expression.

    In case this parameter is True quotes are added when evaluating string parameters, making them the string literals. We assume that in most cases it’s desirable for the user’s parameters to be used as a string literal, so the default value for this is True.

    If you want your string parameters to be interpreted as OneTick expressions, set this to False.

Examples

Generate tick with parametrized field value:

>>> t = otp.Tick(A=otp.param('PARAM', dtype=int))
>>> otp.run(t, query_params={'PARAM': 1})
        Time  A
0 2003-12-01  1

Set bucket interval in aggregation as a parameter:

>>> t = otp.Ticks(A=[1, 2, 3, 4, 5, 6])
>>> t = t.agg({'A': otp.agg.sum('A')},
...           bucket_units='ticks', bucket_interval=otp.param('PARAM', dtype=int))
>>> otp.run(t, query_params={'PARAM': 3})
                     Time   A
0 2003-12-01 00:00:00.002   6
1 2003-12-01 00:00:00.005  15

Parameter string_literal=False can be used if you need string to be interpreted as an expression:

>>> t = otp.Tick(A=otp.param('PARAM', dtype=str),
...              B=otp.param('PARAM', dtype=str, string_literal=False))
>>> otp.run(t, query_params={'PARAM': 'TOSTRING(NAN())'})
        Time                A    B
0 2003-12-01  TOSTRING(NAN())  nan