ethereum.utils.safe_arithmetic

Safe Arithmetic for U256 Integer Type ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. contents:: Table of Contents :backlinks: none :local:

Introduction

Safe arithmetic utility functions for U256 integer type.

u256_safe_add

Adds together the given sequence of numbers. If the total sum of the numbers exceeds U256.MAX_VALUE then an exception is raised. If exception_type = None then the exception raised defaults to the one raised by U256 when U256.value > U256.MAX_VALUE else exception_type is raised.

Parameters

numbers : The sequence of numbers that need to be added together.

exception_type: The exception that needs to be raised if the sum of the numbers exceeds U256.MAX_VALUE.

Returns

result : ethereum.base_types.U256 The sum of the given sequence of numbers if the total is less than U256.MAX_VALUE else an exception is raised. If exception_type = None then the exception raised defaults to the one raised by U256 when U256.value > U256.MAX_VALUE else exception_type is raised.

def u256_safe_add(​*numbers: Union[U256, Uint], ​​exception_type: Optional[Type[BaseException]]​) -> U256:
23
    """
24
    Adds together the given sequence of numbers. If the total sum of the
25
    numbers exceeds `U256.MAX_VALUE` then an exception is raised.
26
    If `exception_type` = None then the exception raised defaults to the one
27
    raised by `U256` when `U256.value > U256.MAX_VALUE`
28
    else `exception_type` is raised.
29
30
    Parameters
31
    ----------
32
    numbers :
33
        The sequence of numbers that need to be added together.
34
35
    exception_type:
36
        The exception that needs to be raised if the sum of the `numbers`
37
        exceeds `U256.MAX_VALUE`.
38
39
    Returns
40
    -------
41
    result : `ethereum.base_types.U256`
42
        The sum of the given sequence of numbers if the total is less than
43
        `U256.MAX_VALUE` else an exception is raised.
44
        If `exception_type` = None then the exception raised defaults to the
45
        one raised by `U256` when `U256.value > U256.MAX_VALUE`
46
        else `exception_type` is raised.
47
    """
48
    try:
49
        return U256(sum(int(n) for n in numbers))
50
    except ValueError as e:
51
        if exception_type:
52
            raise exception_type from e
53
        else:
54
            raise e

u256_safe_multiply

Multiplies together the given sequence of numbers. If the net product of the numbers exceeds U256.MAX_VALUE then an exception is raised. If exception_type = None then the exception raised defaults to the one raised by U256 when U256.value > U256.MAX_VALUE else exception_type is raised.

Parameters

numbers : The sequence of numbers that need to be multiplies together.

exception_type: The exception that needs to be raised if the sum of the numbers exceeds U256.MAX_VALUE.

Returns

result : ethereum.base_types.U256 The multiplication product of the given sequence of numbers if the net product is less than U256.MAX_VALUE else an exception is raised. If exception_type = None then the exception raised defaults to the one raised by U256 when U256.value > U256.MAX_VALUE else exception_type is raised.

def u256_safe_multiply(​*numbers: Union[U256, Uint], ​​exception_type: Optional[Type[BaseException]]​) -> U256:
61
    """
62
    Multiplies together the given sequence of numbers. If the net product of
63
    the numbers exceeds `U256.MAX_VALUE` then an exception is raised.
64
    If `exception_type` = None then the exception raised defaults to the one
65
    raised by `U256` when `U256.value > U256.MAX_VALUE` else
66
    `exception_type` is raised.
67
68
    Parameters
69
    ----------
70
    numbers :
71
        The sequence of numbers that need to be multiplies together.
72
73
    exception_type:
74
        The exception that needs to be raised if the sum of the `numbers`
75
        exceeds `U256.MAX_VALUE`.
76
77
    Returns
78
    -------
79
    result : `ethereum.base_types.U256`
80
        The multiplication product of the given sequence of numbers if the
81
        net product  is less than `U256.MAX_VALUE` else an exception is raised.
82
        If `exception_type` = None then the exception raised defaults to the
83
        one raised by `U256` when `U256.value > U256.MAX_VALUE`
84
        else `exception_type` is raised.
85
    """
86
    result = Uint(numbers[0])
87
    try:
88
        for number in numbers[1:]:
89
            result *= Uint(number)
90
        return U256(result)
91
    except ValueError as e:
92
        if exception_type:
93
            raise exception_type from e
94
        else:
95
            raise e