Common utility functions for ethereum codebases.
Project description
Common utility functions for codebases which interact with ethereum.
This library and repository was previously located at https://github.com/pipermerriam/ethereum-utils. It was transferred to the Ethereum foundation github in November 2017 and renamed to eth-utils. The PyPi package was also renamed from ethereum-utils to `eth-utils.
Installation
pip install eth-utils
Development
Clone the repository and then run:
pip install -e .[dev] eth-hash[pycryptodome]
Running the tests
You can run the tests with:
py.test tests
Or you can install tox to run the full test suite.
Releasing
Pandoc is required for transforming the markdown README to the proper format to render correctly on pypi.
For Debian-like systems:
apt install pandoc
Or on OSX:
brew install pandoc
To release a new version:
make release bump=$$VERSION_PART_TO_BUMP$$
How to bumpversion
The version format for this repo is {major}.{minor}.{patch} for stable, and {major}.{minor}.{patch}-{stage}.{devnum} for unstable (stage can be alpha or beta).
To issue the next version in line, specify which part to bump, like make release bump=minor or make release bump=devnum.
If you are in a beta version, make release bump=stage will switch to a stable.
To issue an unstable version when the current version is stable, specify the new version explicitly, like make release bump="--new-version 4.0.0-alpha.1 devnum"
Documentation
All functions can be imported directly from the eth_utils module
Alternatively, you can get the curried version of the functions by importing them through the curried module like so:
from eth_utils.curried import hexstr_if_str
ABI Utils
event_abi_to_log_topic(event_abi) -> bytes
Returns the 32 byte log topic for the given event abi.
>>> event_abi_to_log_topic({'type': 'event', 'anonymous': False, 'name': 'MyEvent', 'inputs': []})
b'M\xbf\xb6\x8bC\xdd\xdf\xa1+Q\xeb\xe9\x9a\xb8\xfd\xedb\x0f\x9a\n\xc21B\x87\x9aO\x19*\x1byR\xd2'
event_signature_to_log_topic(event_signature) -> bytes
Returns the 32 byte log topic for the given event signature.
>>> event_signature_to_log_topic('MyEvent()')
b'M\xbf\xb6\x8bC\xdd\xdf\xa1+Q\xeb\xe9\x9a\xb8\xfd\xedb\x0f\x9a\n\xc21B\x87\x9aO\x19*\x1byR\xd2'
function_abi_to_4byte_selector(function_abi) -> bytes
Returns the 4 byte function selector for the given function abi.
>>> function_abi_to_4byte_selector({'type': 'function', 'name': 'myFunction', 'inputs': [], 'outputs': []})
b'\xc3x\n:'
function_signature_to_4byte_selector(function_signature) -> bytes
Returns the 4 byte function selector for the given function signature.
>>> function_signature_to_4byte_selector('myFunction()')
b'\xc3x\n:'
Applicators
Applicators help you apply “formatters” in various ways, most notably:
apply formatters to values by key
apply formatters to lists by index
conditionally applying a formatter
conditionally applying one of several formatters.
Here we define a “formatter” as any callable that may be called with a single positional argument. It returns the “formatted” result. For example int() could be used as a formatter.
Defining your own formatter is easy:
def i_put_my_thing_down_flip_it_and_reverse_it(lyric):
return ''.join(reversed(lyric))
These tools often work nicely when curried. Import them from the curried module to get that capability built in, like from eth_utils.curried import apply_formatter_if.
apply_formatter_if(condition, formatter, value) -> new_value
This function will apply the formatter only if bool(condition()) is True.
>>> from eth_utils.curried import apply_formatter_if, is_string
>>> bool_if_string = apply_formatter_if(is_string, bool)
>>> bool_if_string(1)
1
>>> bool_if_string('1')
True
>>> bool_if_string('')
False
apply_one_of_formatters(condition_formatter_pairs, value) -> new_value
This function will iterate through condition_formatter_pairs, and apply the first formatter which has a truthy condition. One of the formatters must match, or this function will raise a ValueError.
>>> from eth_utils.curried import apply_one_of_formatters, is_string, is_list_like
>>> multi_formatter = apply_one_of_formatters((
(is_list_like, tuple),
(is_string, i_put_my_thing_down_flip_it_and_reverse_it),
)
>>> multi_formatter('my thing')
'gniht ym'
>>> multi_formatter([1, 2])
(1, 2)
>>> multi_formatter(54)
ValueError("The provided value did not satisfy any of the formatter conditions")
apply_formatter_at_index(formatter, at_index, <list_like>) ->
This function will apply the formatter to one element of list_like, at position at_index, and return a new iterable with that element replaced. The returned value will be the same type as the one passed into the third argument.
>>> from eth_utils.curried import apply_formatter_at_index
>>> targetted_formatter = apply_formatter_at_index(bool, 1)
>>> targetted_formatter((1, 2, 3))
(1, True, 3)
>>> targetted_formatter([1, 2, 3])
[1, True, 3]
apply_formatter_to_array(formatter, <list_like>) ->
This function will apply the formatter to each element of list_like. It returns the same type as the list_like argument
>>> from eth_utils.curried import apply_formatter_to_array
>>> map_int = apply_formatter_to_array(int)
>>> map_int((1.2, 3.4, 5.6))
(1, 3, 5)
>>> map_int([1.2, 3.4, 5.6])
[1, 3, 5]
apply_formatters_to_sequence(formatters, <list_like>) ->
This function will apply each formatter at to the list-like value, at the position it was supplied. It returns the same time as the list_like argument. For example:
>>> from eth_utils.curried import apply_formatters_to_sequence
>>> list_formatter = apply_formatters_to_sequence([bool, int, str])
>>> list_formatter([1.2, 3.4, 5.6])
[True, 3, '5.6']
>>> list_formatter((1.2, 3.4, 5.6))
(True, 3, '5.6')
# Formatters and list-like value must be the same length
>>> list_formatter((1.2, 3.4, 5.6, 7.8))
IndexError: Too few formatters for sequence: 3 formatters for (1.2, 3.4, 5.6, 7.8)
>>> list_formatter((1.2, 3.4))
IndexError: Too many formatters for sequence: 3 formatters for (1.2, 3.4)
combine_argument_formatters(*formatters) -> lambda :
DEPRECATED
You can replace all current versions of:
>>> from eth_utils import combine_argument_formatters
>>> list_formatter = combine_argument_formatters(bool, int, str)
With the newer, preferred:
>>> from eth_utils.curried import apply_formatters_to_sequence
>>> list_formatter = apply_formatters_to_sequence((bool, int, str))
The old usage works like:
Combine several formatters to be applied to a list-like value, each formatter at the position it was supplied. The new formatter will return the same type as it was supplied. For example:
>>> from eth_utils import combine_argument_formatters
>>> list_formatter = combine_argument_formatters(bool, int, str)
>>> list_formatter([1.2, 3.4, 5.6])
[True, 3, '5.6']
>>> list_formatter((1.2, 3.4, 5.6))
(True, 3, '5.6')
# it will pass through items longer than the number of formatters supplied
>>> list_formatter((1.2, 3.4, 5.6, 7.8))
[True, 3, '5.6', 7.8]
apply_formatters_to_dict(formatter_dict, <dict_like>) -> dict
This function will apply the formatter to the element with the matching key in dict_like, passing through values with keys that have no matching formatter.
>>> from eth_utils.curried import apply_formatters_to_dict
>>> dict_formatter = apply_formatters_to_dict({
'should_be_int': int,
'should_be_bool': bool,
})
>>> dict_formatter({
'should_be_int': 1.2,
'should_be_bool': 3.4,
'pass_through': 5.6,
})
{
'should_be_int': 1,
'should_be_bool': True,
'pass_through': 5.6,
}
apply_key_map(formatter_dict, <dict_like>) -> dict
This function will rename keys from using the lookups provided in formatter_dict. It will pass through any unspecified keys.
>>> from eth_utils.curried import apply_key_map
>>> dict_key_map = apply_key_map({
'black': 'orange',
'Internet': 'Ethereum',
})
>>> dict_key_map({
'black': 1.2,
'Internet': 3.4,
'pass_through': 5.6,
})
{
'orange': 1.2,
'Ethereum': 3.4,
'pass_through': 5.6,
}
Address Utils
is_address(value) -> bool
Returns True if the value is one of the following accepted address formats.
20 byte hexadecimal, upper/lower/mixed case, with or without 0x prefix:
'd3cda913deb6f67967b99d67acdfa1712c293601'
'0xd3cda913deb6f67967b99d67acdfa1712c293601'
'0xD3CDA913DEB6F67967B99D67ACDFA1712C293601'
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
20 byte hexadecimal padded to 32 bytes with null bytes, upper/lower/mixed case, with or without 0x prefix:
'000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601'
'000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601'
'0x000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601'
'0x000000000000000000000000D3CDA913DEB6F67967B99D67ACDFA1712C293601'
'0x000000000000000000000000d3CdA913deB6f67967B99D67aCDFa1712C293601'
20 text or bytes string:
'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
20 text or bytes string padded to 32 bytes with null bytes.
'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
This function has two special cases when it will return False:
a 20-byte hex string that has mixed case, with an invalid checksum
a 32-byte value that is all null bytes
>>> is_address('d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0x000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0x000000000000000000000000D3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_address('0x000000000000000000000000d3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
True
>>> is_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
True
>>> is_address('0x0000000000000000000000000000000000000000000000000000000000000000')
False
>>> is_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
False
is_hex_address(value) => bool
Return True if the value is a 20 byte hexadecimal encoded string in any of upper/lower/mixed casing, with or without the 0x prefix. Otherwise return False
'd3cda913deb6f67967b99d67acdfa1712c293601'
'0xd3cda913deb6f67967b99d67acdfa1712c293601'
'0xD3CDA913DEB6F67967B99D67ACDFA1712C293601'
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> is_hex_address('d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_hex_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_hex_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_hex_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_hex_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_hex_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_hex_address('0x000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_hex_address('0x000000000000000000000000D3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_hex_address('0x000000000000000000000000d3CdA913deB6f67967B99D67aCDFa1712C293601')
False
>>> is_hex_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
False
>>> is_hex_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
False
>>> is_hex_address('0x0000000000000000000000000000000000000000000000000000000000000000')
False
>>> is_hex_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
False
is_binary_address(value) -> bool
Return True if the value is a 20 byte string.
>>> is_binary_address('d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_binary_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_binary_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_binary_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
False
>>> is_binary_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_binary_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_binary_address('0x000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_binary_address('0x000000000000000000000000D3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_binary_address('0x000000000000000000000000d3CdA913deB6f67967B99D67aCDFa1712C293601')
False
>>> is_binary_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
True
>>> is_binary_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
False
>>> is_binary_address('0x0000000000000000000000000000000000000000000000000000000000000000')
False
>>> is_binary_address('\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
False
is_canonical_address(value) -> bool
Returns True if the value is an address in it’s canonical form.
The canonical representation of an address according to eth_utils is a 20 byte long string of bytes, eg: b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
>>> is_canonical_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_canonical_address(b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
True
>>> is_canonical_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
False
is_checksum_address(value) -> bool
Returns True if the value is a checksummed address as specified by ERC55
>>> is_checksum_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_checksum_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_checksum_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_checksum_address('0x52908400098527886E0F7030069857D2E4169EE7')
True
>>> is_checksum_address('0xde709f2102306220921060314715629080e2fb77')
True
is_checksum_formatted_address(value) -> bool
Returns True if the value is formatted as an ERC55 checksum address.
>>> is_checksum_formatted_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_checksum_formatted_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_checksum_formatted_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_checksum_formatted_address('0x52908400098527886E0F7030069857D2E4169EE7')
False
>>> is_checksum_formatted_address('0xde709f2102306220921060314715629080e2fb77')
False
is_normalized_address(value) -> bool
Returns True if the value is an address in its normalized form.
The normalized representation of an address is the lowercased 20 byte hexadecimal format.
>>> is_normalized_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
False
>>> is_normalized_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_normalized_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_normalized_address('0x52908400098527886E0F7030069857D2E4169EE7')
False
>>> is_normalized_address('0xde709f2102306220921060314715629080e2fb77')
True
is_same_address(a, b) -> bool
Returns True if both a and b are valid addresses according to the is_address function and that they are both representations of the same address.
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', '0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', '0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', '\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
True
to_canonical_address(value) -> bytes
Given any valid representation of an address return it’s canonical form.
>>> to_canonical_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd'
>>> to_canonical_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd'
>>> to_canonical_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd'
>>> to_canonical_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd'
to_checksum_address(value) -> text
Given any valid representation of an address return the checksummed representation.
>>> to_checksum_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
to_normalized_address(value) -> text
Given any valid representation of an address return the normalized representation.
>>> to_normalized_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01') # raw bytes
'0xd3cda913deb6f67967b99d67acdfa1712c293601'
>>> to_normalized_address(b'0xc6d9d2cd449a754c494264e1809c50e34d64562b') # hex encoded (as byte string)
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
>>> to_normalized_address('0xc6d9d2cd449a754c494264e1809c50e34d64562b') # hex encoded
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
>>> to_normalized_address('0XC6D9D2CD449A754C494264E1809C50E34D64562B') # cap-cased
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
>>> to_normalized_address('0x000000000000000000000000c305c901078781c232a2a521c2af7980f8385ee9') # padded to 32 bytes
'0xc305c901078781c232a2a521c2af7980f8385ee9',
Conversion Utils
These methods convert values using standard practices in the Ethereum ecosystem. For example, strings are encoded to binary using UTF-8.
Because there is no reliable way to distinguish between text and a hex-encoded bytestring, you must explicitly specify which of the two is being supplied when passing in a str.
Only supply one of the arguments:
to_bytes(<bytes/int/bool>, text=<str>, hexstr=<str>) -> bytes
Takes a variety of inputs and returns its bytes equivalent. Text gets encoded as UTF-8.
>>> to_bytes(0)
b'\x00'
>>> to_bytes(0x000F)
b'\x0f'
>>> to_bytes(b'')
b''
>>> to_bytes(b'\x00\x0F')
b'\x00\x0f'
>>> to_bytes(False)
b'\x00'
>>> to_bytes(True)
b'\x01'
>>> to_bytes(hexstr='0x000F')
b'\x00\x0f'
>>> to_bytes(hexstr='000F')
b'\x00\x0f'
>>> to_bytes(text='')
b''
>>> to_bytes(text='cowmö')
b'cowm\xc3\xb6'
to_hex(<bytes/int/bool>, text=<str>, hexstr=<str>) -> str
Takes a variety of inputs and returns it in its hexadecimal representation. It follows the rules for converting to hex in the JSON-RPC spec. Roughly, it leaves leading 0s on bytes input, and trims leading zeros on int input.
>>> to_hex(0)
'0x0'
>>> to_hex(1)
'0x1'
>>> to_hex(0x0)
'0x0'
>>> to_hex(0x000F)
'0xf'
>>> to_hex(b'')
'0x'
>>> to_hex(b'\x00\x0F')
'0x000f'
>>> to_hex(False)
'0x0'
>>> to_hex(True)
'0x1'
>>> to_hex(hexstr='0x000F')
'0x000f'
>>> to_hex(hexstr='000F')
'0x000f'
>>> to_hex(text='')
'0x'
>>> to_hex(text='cowmö')
'0x636f776dc3b6'
to_int(<bytes/int/bool>, text=<str>, hexstr=<str>) -> int
Takes a variety of inputs and returns its integer equivalent.
>>> to_int(0)
0
>>> to_int(0x000F)
15
>>> to_int(b'\x00\x0F')
15
>>> to_int(False)
0
>>> to_int(True)
1
>>> to_int(hexstr='0x000F')
15
>>> to_int(hexstr='000F')
15
to_text(<bytes/int/bool>, text=<str>, hexstr=<str>) -> str
Takes a variety of inputs and returns its string equivalent. Text gets decoded as UTF-8.
>>> Web3.toText(0x636f776dc3b6)
'cowmö'
>>> Web3.toText(b'cowm\xc3\xb6')
'cowmö'
>>> Web3.toText(hexstr='0x636f776dc3b6')
'cowmö'
>>> Web3.toText(hexstr='636f776dc3b6')
'cowmö'
>>> Web3.toText(text='cowmö')
'cowmö'
Crypto Utils
Because there is no reliable way to distinguish between text and a hex-encoded bytestring, you must explicitly specify which of the two is being supplied when passing in a str.
Only supply one of the arguments:
keccak(<bytes/int/bool>, text=<str>, hexstr=<str>) -> bytes
>>> keccak(text='')
b"\xc5\xd2F\x01\x86\xf7#<\x92~}\xb2\xdc\xc7\x03\xc0\xe5\x00\xb6S\xca\x82';{\xfa\xd8\x04]\x85\xa4p"
# A series of equivalent hash inputs:
>>> keccak(text='☢')
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(0xe298a2)
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(b'\xe2\x98\xa2')
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(hexstr='0xe298a2')
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
Please Note - When using Python’s native hex literals, python converts the hex to an int, so leading 0 bytes are truncated. But all other formats maintain zeros on the left. Hex literals are only padded until a whole number of bytes are provided to keccak. For example:
>>> keccak(0xe298a2)
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(0x0e298a2)
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(0x00e298a2)
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(0x000e298a2)
b'\x85\xe8\x07"\xeb\x93\r\xe9;\xcc\xa8{\xa5\xdf\xda\x89\n\xa12\x95\xae\xad.\xec\xc9\x0b\xb2\xd9z\x14\x93\x16'
>>> keccak(hexstr='0x0e298a2')
b'i\x0f$\xbd\xbe\xf7c\xbb\xb9M\xd9\x12H"\x9f\x1f\x87\\E\xa36\xc2\xea,\x8f.\r\xf5\x95\xdc\x19\x9b'
>>> keccak(hexstr='0x00e298a2')
b'i\x0f$\xbd\xbe\xf7c\xbb\xb9M\xd9\x12H"\x9f\x1f\x87\\E\xa36\xc2\xea,\x8f.\r\xf5\x95\xdc\x19\x9b'
>>> keccak(hexstr='0x000e298a2')
b'!$Ezy\xdeU<\xec\x1f\xd1\x10\x05\xff\x11\xfc=J\xcf\xd5H\x0f\xb3c\xcc\xb5\xae\xb1\x1eA\x8b\xd3'
Currency Utils
denoms
Object with property access to all of the various denominations for ether. Available denominations are:
denomination |
amount in wei |
wei kwei babbage femtoether mwei lovelace picoether gwei shannon nanoether nano szabo microether micro finney milliether milli ether kether grand mether gether tether |
1 1000 1000 1000 1000000 1000000 1000000 1000000000 1000000000 1000000000 1000000000 1000000000000 1000000000000 1000000000000 1000000000000000 1000000000000000 1000000000000000 1000000000000000000 1000000000000000000000 1000000000000000000000 1000000000000000000000000 1000000000000000000000000000 1000000000000000000000000000000 |
>>> denoms.wei
1
>>> denoms.finney
1000000000000000
>>> denoms.ether
1000000000000000000
to_wei(value, denomination) -> integer
Converts value in the given denomination to its equivalent in the wei denomination.
>>> to_wei(1, 'ether')
1000000000000000000
from_wei(value, denomination) -> decimal.Decimal
Converts the value in the wei denomination to its equivalent in the given denomination. Return value is a decimal.Decimal with the appropriate precision to be a lossless conversion.
>>> from_wei(1000000000000000000, 'ether')
Decimal('1')
>>> from_wei(123456789, 'ether')
Decimal('1.23456789E-10')
Debug Utils
Generate environment info
At the shell:
$ python -m eth_utils
Python version:
3.5.3 (default, Nov 23 2017, 11:34:05)
[GCC 6.3.0 20170406]
Operating System: Linux-4.10.0-42-generic-x86_64-with-Ubuntu-17.04-zesty
pip freeze result:
bumpversion==0.5.3
cytoolz==0.9.0
flake8==3.4.1
ipython==6.2.1
pytest==3.3.2
virtualenv==15.1.0
... etc
Decorators
@combomethod
Decorates methods in a class that can be called as both an instance method or a @classmethod.
Use the decorator like so:
from eth_utils import combomethod
class Storage:
val = 1
@combomethod
def get(combo):
if isinstance(combo, type):
print("classmethod call")
elif isinstance(combo, Storage):
print("instance method call")
else:
raise TypeError("Unreachable, unless you really monkey around")
return combo.val
As usual, instances create their own copy on assignment.
>>> store = Storage()
>>> store.val = 2
>>> store.get()
instance method call
2
>>> Storage.get()
classmethod call
1
Encoding Utils
big_endian_to_int(value) -> integer
Returns value converted to an integer (from a big endian representation).
>>> big_endian_to_int(b'\x00')
0
>>> big_endian_to_int(b'\x01')
1
>>> big_endian_to_int(b'\x01\x00')
256
int_to_big_endian(value) -> bytes
Returns value converted to the big endian representation.
>>> int_to_big_endian(0)
b'\x00'
>>> int_to_big_endian(1)
b'\x01'
>>> int_to_big_endian(256)
b'\x01\x00'
Functional Utils
compose(*callables) -> callable
DEPRECATED in 0.3.0.
Returns a single function which is the composition of the given callables.
>>> def f(v): ... return v * 3 ... >>> def g(v): ... return v + 2 ... >>> def h(v): ... return v % 5 ... >>> compose(f, g, h)(1) 0 >>> h(g(f(1))) 0 >>> compose(f, g, h)(2) 3 >>> h(g(f(1))) 3 >>> compose(f, g, h)(3) 1 >>> h(g(f(1))) 1 >>> compose(f, g, h)(4) 4 >>> h(g(f(1))) 4
flatten_return(callable) -> callable() -> tuple
Decorator which performs a non-recursive flattening of the return value from the given callable.
>>> flatten_return(lambda: [[1, 2, 3], [4, 5], [6]])
(1, 2, 3, 4, 5, 6)
sort_return(callable) => callable() -> tuple
Decorator which sorts the return value from the given callable.
>>> flatten_return(lambda: [[1, 2, 3], [4, 5], [6]])
(1, 2, 3, 4, 5, 6)
reversed_return(callable) => callable() -> tuple
Decorator which reverses the return value from the given callable.
>>> reversed_return(lambda: [1, 5, 2, 4, 3])
(3, 4, 2, 5, 1)
to_dict(callable) => callable() -> dict
Decorator which casts the return value from the given callable to a dictionary.
>>> @to_dict
... def build_thing():
... yield 'a', 1
... yield 'b', 2
... yield 'c', 3
...
>>> build_thing()
{'a': 1, 'b': 2, 'c': 3}
to_list(callable) => callable() -> list
Decorator which casts the return value from the given callable to a list.
>>> @to_list
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'c'
...
>>> build_thing()
['a', 'b', 'c']
to_ordered_dict(callable) => callable() -> collections.OrderedDict
Decorator which casts the return value from the given callable to an ordered dictionary of type collections.OrderedDict.
>>> @to_ordered_dict
... def build_thing():
... yield 'd', 4
... yield 'a', 1
... yield 'b', 2
... yield 'c', 3
...
>>> build_thing()
OrderedDict([('d', 4), ('a', 1), ('b', 2), ('c', 3)])
to_tuple(callable) => callable() -> tuple
Decorator which casts the return value from the given callable to a tuple.
>>> @to_tuple
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'c'
...
>>> build_thing()
('a', 'b', 'c')
to_set(callable) => callable() -> set
Decorator which casts the return value from the given callable to a set.
>>> @to_set
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'a' # duplicate
... yield 'c'
...
>>> build_thing()
{'a', 'b', 'c'}
apply_to_return_value(callable) => decorator_fn
This function takes a single callable and returns a decorator. The returned decorator, when applied to a function, will incercept the function’s return value, pass it to the callable, and return the value returned by the callable.
>>> double = apply_to_return_value(lambda v: v * 2)
>>> @double
... def f(v):
... return v
...
>>> f(2)
4
>>> f(3)
6
Hexidecimal Utils
add_0x_prefix(value) -> string
Returns value with a 0x prefix. If the value is already prefixed it is returned as-is.
>>> add_0x_prefix('12345')
'0x12345'
>>> add_0x_prefix('0x12345')
'0x12345'
decode_hex(value) -> bytes
Returns value decoded into a byte string. Accepts any string with or without the 0x prefix.
>>> decode_hex('0x123456')
b'\x124V'
>>> decode_hex('123456')
b'\x124V'
encode_hex(value) -> string
Returns value encoded into a hexadecimal representation with a 0x prefix
>>> encode_hex('\x01\x02\x03')
'0x010203'
is_0x_prefixed(value) -> bool
Returns True if value has a 0x prefix.
>>> is_0x_prefixed('12345')
False
>>> is_0x_prefixed('0x12345')
True
>>> is_0x_prefixed(b'0x12345')
True
is_hex(value) -> bool
Returns True if value is a hexadecimal encoded string of text type.
>>> is_hex('')
False
>>> is_hex(b'')
False
>>> is_hex('0x')
True
>>> is_hex(b'0x')
False
>>> is_hex('0X')
True
>>> is_hex(b'0X')
False
>>> is_hex('1234567890abcdef')
True
>>> is_hex('0x1234567890abcdef')
True
>>> is_hex('0x1234567890ABCDEF')
True
>>> is_hex('0x1234567890AbCdEf')
True
>>> is_hex('12345') # odd length is ok
True
>>> is_hex('0x12345') # odd length is ok
True
>>> is_hex('123456__abcdef') # non hex characters
False
remove_0x_prefix(value) -> string
Returns value with the 0x prefix stripped. If the value does not have a 0x prefix it is returned as-is.
>>> remove_0x_prefix('12345')
'12345'
>>> remove_0x_prefix('0x12345')
'12345'
>>> remove_0x_prefix(b'0x12345')
b'12345'
Type Utils
is_boolean(value) -> bool
Returns True if value is of type bool
>>> is_boolean(True)
True
>>> is_boolean(False)
False
>>> is_boolean(1)
False
is_bytes(value) -> bool
Returns True if value is a byte string or a byte array.
>>> is_bytes('abcd')
False
>>> is_bytes(b'abcd')
True
>>> is_bytes(bytearray((1, 2, 3)))
True
is_dict(value) -> bool
Returns True if value is a mapping type.
>>> is_dict({'a': 1})
True
>>> is_dict([1, 2, 3])
False
is_integer(value) -> bool
Returns True if value is an integer
>>> is_integer(0)
True
>>> is_integer(1)
True
>>> is_integer('1')
False
>>> is_integer(1.1)
False
is_list_like(value) -> bool
Returns True if value is a non-string sequence such as a sequence (such as a list or tuple).
>>> is_list_like('abcd')
False
>>> is_list_like([])
True
>>> is_list_like(tuple())
True
is_list(value) -> bool
Returns True if value is a non-string sequence such as a list.
>>> is_list('abcd')
False
>>> is_list([])
True
>>> is_list(tuple())
False
is_tuple(value) -> bool
Returns True if value is a non-string sequence such as a tuple.
>>> is_tuple('abcd')
False
>>> is_tuple([])
False
>>> is_tuple(tuple())
True
is_null(value) -> bool
Returns True if value is None
>>> is_null(None)
True
>>> is_null(False)
False
is_number(value) -> bool
Returns True if value is numeric
>>> is_number(1)
True
>>> is_number(1.1)
True
>>> is_number('1')
False
>>> is_number(decimal.Decimal('1'))
True
is_string(value) -> bool
Returns True if value is of any string type.
>>> is_string('abcd')
True
>>> is_string(b'abcd')
True
>>> is_string(bytearray((1, 2, 3)))
True
is_text(value) -> bool
Returns True if value is a text string.
>>> is_text(u'abcd')
True
>>> is_text(b'abcd')
False
>>> is_text(bytearray((1, 2, 3)))
False
How to bumpversion
The version format for this repo is {major}.{minor}.{patch} for stable, and {major}.{minor}.{patch}-{stage}.{devnum} for unstable (stage can be alpha or beta).
To issue the next version in line, use bumpversion and specify which part to bump, like bumpversion minor or bumpversion devnum.
If you are in a beta version, bumpversion stage will switch to a stable.
To issue an unstable version when the current version is stable, specify the new version explicitly, like bumpversion --new-version 4.0.0-alpha.1 devnum
Project details
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