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
Returns the 32 byte log topic for the given event abi.
>>> from eth_utils import event_abi_to_log_topic
>>> 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'
Returns the 32 byte log topic for the given event signature.
>>> from eth_utils import event_signature_to_log_topic
>>> 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'
Returns the 4 byte function selector for the given function abi.
>>> from eth_utils import function_abi_to_4byte_selector
>>> function_abi_to_4byte_selector({'type': 'function', 'name': 'myFunction', 'inputs': [], 'outputs': []})
b'\xc3x\n:'
Returns the 4 byte function selector for the given function signature.
>>> from eth_utils import function_signature_to_4byte_selector
>>> function_signature_to_4byte_selector('myFunction()')
b'\xc3x\n:'
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
.
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
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")
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]
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]
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))
Traceback (most recent call last):
IndexError: Too few formatters for sequence: 3 formatters for (1.2, 3.4, 5.6, 7.8)
>>> list_formatter((1.2, 3.4))
Traceback (most recent call last):
IndexError: Too many formatters for sequence: 3 formatters for (1.2, 3.4)
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)
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,
... })
>>> result = dict_formatter({
... 'should_be_int': 1.2,
... 'should_be_bool': 3.4,
... 'pass_through': 5.6,
... })
>>> result == {'should_be_int': 1, 'should_be_bool': True, 'pass_through': 5.6}
True
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',
... })
>>> result = dict_key_map({
... 'black': 1.2,
... 'Internet': 3.4,
... 'pass_through': 5.6,
... })
>>> result == {'orange': 1.2, 'Ethereum': 3.4, 'pass_through': 5.6}
True
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, upper/lower/mixed case, with or without
- 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'
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
>>> from eth_utils import is_address
>>> is_address('d3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
True
>>> is_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_address('000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_address('0x000000000000000000000000d3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_address('0x000000000000000000000000D3CDA913DEB6F67967B99D67ACDFA1712C293601')
False
>>> is_address('0x000000000000000000000000d3CdA913deB6f67967B99D67aCDFa1712C293601')
False
>>> is_address(b'\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')
False
>>> 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
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'
>>> from eth_utils import is_hex_address
>>> 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
Return True
if the value is a 20 byte string.
>>> from eth_utils import is_binary_address
>>> 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(b'\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
Returns True
if the value
is an address in its 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'
>>> from eth_utils import is_canonical_address
>>> is_canonical_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
False
>>> is_canonical_address(b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
True
>>> is_canonical_address('\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01xd')
False
Returns True
if the value
is a checksummed address as specified
by ERC55
>>> from eth_utils import is_checksum_address
>>> 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
Returns True
if the value
is formatted as an
ERC55 checksum address.
>>> from eth_utils import is_checksum_formatted_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
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.
>>> from eth_utils import is_normalized_address
>>> 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
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.
>>> from eth_utils import is_same_address
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', '0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
True
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', '0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
True
>>> is_same_address('0xd3cda913deb6f67967b99d67acdfa1712c293601', b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
True
to_canonical_address(value)
-> Address
Given any valid representation of an address return its canonical form.
>>> from eth_utils import to_canonical_address
>>> to_canonical_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
>>> to_canonical_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
>>> to_canonical_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
>>> to_canonical_address(b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01'
to_checksum_address(value)
-> ChecksumAddress
Given any valid representation of an address return the checksummed representation.
>>> from eth_utils import to_checksum_address
>>> to_checksum_address('0xd3cda913deb6f67967b99d67acdfa1712c293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address('0xD3CDA913DEB6F67967B99D67ACDFA1712C293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address('0xd3CdA913deB6f67967B99D67aCDFa1712C293601')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
>>> to_checksum_address(b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01')
'0xd3CdA913deB6f67967B99D67aCDFa1712C293601'
to_normalized_address(value)
-> HexAddress
Given any valid representation of an address return the normalized representation.
>>> from eth_utils import to_normalized_address
>>> to_normalized_address(b'\xd3\xcd\xa9\x13\xde\xb6\xf6yg\xb9\x9dg\xac\xdf\xa1q,)6\x01') # raw bytes
'0xd3cda913deb6f67967b99d67acdfa1712c293601'
>>> to_normalized_address('c6d9d2cd449a754c494264e1809c50e34d64562b') # hex encoded
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
>>> to_normalized_address('0xc6d9d2cd449a754c494264e1809c50e34d64562b') # hex encoded
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
>>> to_normalized_address('0XC6D9D2CD449A754C494264E1809C50E34D64562B') # cap-cased
'0xc6d9d2cd449a754c494264e1809c50e34d64562b'
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:
Takes a variety of inputs and returns its bytes equivalent. Text gets encoded as UTF-8.
>>> from eth_utils import to_bytes
>>> 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>)
-> HexStr
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.
>>> from eth_utils import to_hex
>>> 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'
Takes a variety of inputs and returns its integer equivalent.
>>> from eth_utils import to_int
>>> 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
Takes a variety of inputs and returns its string equivalent. Text gets decoded as UTF-8.
>>> from eth_utils import to_text
>>> to_text(0x636f776dc3b6)
'cowmö'
>>> to_text(b'cowm\xc3\xb6')
'cowmö'
>>> to_text(hexstr='0x636f776dc3b6')
'cowmö'
>>> to_text(hexstr='636f776dc3b6')
'cowmö'
>>> to_text(text='cowmö')
'cowmö'
Convert text_or_primitive with the provided to_type function. Assumes the input string or primitive will be unicode text.
Return type T is the same as the return type of the provided to_type function.
>>> from eth_utils import text_if_str, to_bytes
>>> text_if_str(to_bytes, 0)
b'\x00'
>>> text_if_str(to_hex, 0)
'0x0'
>>> text_if_str(to_int, 0)
0
>>> text_if_str(to_text, 0)
'\x00'
Convert text_or_primitive with the provided to_type function. Assumes the input string or primitive will be hexstr.
Return type T is the same as the return type of the provided to_type function.
>>> from eth_utils import hexstr_if_str, to_bytes
>>> hexstr_if_str(to_bytes, '0x000F')
b'\x00\x0f'
>>> hexstr_if_str(to_hex, '0x000F')
'0x000f'
>>> hexstr_if_str(to_int, '0x000F')
15
>>> hexstr_if_str(to_text, '0x000F')
'\x00\x0f'
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:
>>> from eth_utils import keccak
>>> 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'
Object with property access to all of the various denominations for ether. Available denominations are:
denomination | amount in wei |
---|---|
wei | 1 |
kwei | 1000 |
babbage | 1000 |
femtoether | 1000 |
mwei | 1000000 |
lovelace | 1000000 |
picoether | 1000000 |
gwei | 1000000000 |
shannon | 1000000000 |
nanoether | 1000000000 |
nano | 1000000000 |
szabo | 1000000000000 |
microether | 1000000000000 |
micro | 1000000000000 |
finney | 1000000000000000 |
milliether | 1000000000000000 |
milli | 1000000000000000 |
ether | 1000000000000000000 |
kether | 1000000000000000000000 |
grand | 1000000000000000000000 |
mether | 1000000000000000000000000 |
gether | 1000000000000000000000000000 |
tether | 1000000000000000000000000000000 |
>>> from eth_utils import denoms
>>> denoms.wei
1
>>> denoms.finney
1000000000000000
>>> denoms.ether
1000000000000000000
Converts value
in the given denomination
to its equivalent in
the wei denomination.
>>> from eth_utils import to_wei
>>> to_wei(1, 'ether')
1000000000000000000
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 eth_utils import from_wei
>>> from_wei(1000000000000000000, 'ether')
Decimal('1')
>>> from_wei(123456789, 'ether')
Decimal('1.23456789E-10')
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
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
Replaces Old exceptions in a method with New exceptions. Accepts a Dict, with Old exceptions pointing to New exceptions.
>>> from eth_utils import replace_exceptions
>>> @replace_exceptions({TypeError: AttributeError})
... def thing(self):
... if True:
... raise TypeError
>>> thing()
Traceback (most recent call last):
...
AttributeError
Calling thing() will raise an AttributeError
Returns value
converted to an integer (from a big endian
representation).
>>> from eth_utils import big_endian_to_int
>>> big_endian_to_int(b'\x00')
0
>>> big_endian_to_int(b'\x01')
1
>>> big_endian_to_int(b'\x01\x00')
256
Returns value
converted to the big endian representation.
>>> from eth_utils import int_to_big_endian
>>> int_to_big_endian(0)
b'\x00'
>>> int_to_big_endian(1)
b'\x01'
>>> int_to_big_endian(256)
b'\x01\x00'
An exception that is raised when something does not pass a validation check.
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
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)
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)
Decorator which reverses the return value from the given callable
.
>>> reversed_return(lambda: [1, 5, 2, 4, 3])
(3, 4, 2, 5, 1)
Decorator which casts the return value from the given callable
to a
dictionary.
>>> from eth_utils import to_dict
>>> @to_dict
... def build_thing():
... yield 'a', 1
... yield 'b', 2
... yield 'c', 3
...
>>> build_thing() == {'a': 1, 'b': 2, 'c': 3}
True
Decorator which casts the return value from the given callable
to a
list.
>>> from eth_utils import to_list
>>> @to_list
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'c'
...
>>> build_thing()
['a', 'b', 'c']
Decorator which casts the return value from the given callable
to an
ordered dictionary of type collections.OrderedDict
.
>>> from eth_utils import to_ordered_dict
>>> @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)])
Decorator which casts the return value from the given callable
to a
tuple.
>>> from eth_utils import to_tuple
>>> @to_tuple
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'c'
...
>>> build_thing()
('a', 'b', 'c')
Decorator which casts the return value from the given callable
to a
set.
>>> from eth_utils import to_set
>>> @to_set
... def build_thing():
... yield 'a'
... yield 'b'
... yield 'a' # duplicate
... yield 'c'
...
>>> build_thing() == {'c', 'b', 'a'}
True
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.
>>> from eth_utils import apply_to_return_value
>>> double = apply_to_return_value(lambda v: v * 2)
>>> @double
... def f(v):
... return v
...
>>> f(2)
4
>>> f(3)
6
add_0x_prefix(value: HexStr)
-> HexStr
Returns value
with a 0x
prefix. If the value is already prefixed
it is returned as-is. Value must be a HexStr.
>>> from eth_utils import add_0x_prefix
>>> from eth_typing import HexStr
>>> add_0x_prefix(HexStr('12345'))
'0x12345'
>>> add_0x_prefix(HexStr('0x12345'))
'0x12345'
Returns value
decoded into a byte string. Accepts any string with or
without the 0x
prefix.
>>> from eth_utils import decode_hex
>>> decode_hex('0x123456')
b'\x124V'
>>> decode_hex('123456')
b'\x124V'
Returns value
encoded into a hexadecimal representation with a
0x
prefix
>>> from eth_utils import encode_hex
>>> encode_hex(b'\x01\x02\x03')
'0x010203'
Returns True
if value
has a 0x
prefix. Value must be a
string literal.
>>> from eth_utils import is_0x_prefixed
>>> is_0x_prefixed('12345')
False
>>> is_0x_prefixed('0x12345')
True
Returns True
if value
is a hexadecimal encoded string of text
type.
>>> from eth_utils import is_hex
>>> is_hex('')
False
>>> is_hex('0x')
True
>>> is_hex('0X')
True
>>> 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
# invalid, will raise TypeError:
>>> is_hex(b'')
Traceback (most recent call last):
TypeError: is_hex requires text typed arguments.
>>> is_hex(b'0x')
Traceback (most recent call last):
TypeError: is_hex requires text typed arguments.
>>> is_hex(b'0X')
Traceback (most recent call last):
TypeError: is_hex requires text typed arguments.
Returns True
if value
is a hexadecimal encoded string of text
type.
Note
This function differs from is_hex(value: Any)
in that it will return
False on all non-text type arguments, while is_hex
will raise a TypeError
for all non-text type arguments.
>>> from eth_utils import is_hexstr
>>> is_hexstr('')
False
>>> is_hexstr('0x')
True
>>> is_hexstr('0X')
True
>>> is_hexstr('1234567890abcdef')
True
>>> is_hexstr('0x1234567890abcdef')
True
>>> is_hexstr('0x1234567890ABCDEF')
True
>>> is_hexstr('0x1234567890AbCdEf')
True
>>> is_hexstr('12345') # odd length is ok
True
>>> is_hexstr('0x12345') # odd length is ok
True
>>> is_hexstr('123456__abcdef') # non hex characters
False
>>> is_hexstr(b'') # any non-string returns False
False
>>> is_hexstr(b'0x') # any non-string returns False
False
remove_0x_prefix(value: HexStr)
-> HexStr
Returns value
with the 0x
prefix stripped. If the value does not
have a 0x
prefix it is returned as-is. Value must be a HexStr.
>>> from eth_utils import remove_0x_prefix
>>> from eth_typing import HexStr
>>> remove_0x_prefix(HexStr('12345'))
'12345'
>>> remove_0x_prefix(HexStr('0x12345'))
'12345'
Returns the provide number of seconds as a shorthand string.
>>> from eth_utils import humanize_seconds
>>> humanize_seconds(0)
'0s'
>>> humanize_seconds(1)
'1s'
>>> humanize_seconds(60)
'1m'
>>> humanize_seconds(61)
'1m1s'
Returns the provided byte string in a human readable format.
If the value is 5 bytes or less it is returned in full in its hexadecimal representation (without a 0x
prefix)
If the value is longer that 5 bytes it is returned in its hexadecimal
representation (without a 0x
prefix) with the middle segment replaced by an
ellipsis, only showing the first and last four hexadecimal nibbles.
>>> from eth_utils import humanize_bytes
>>> humanize_bytes(bytes(range(3)))
'000102'
>>> humanize_bytes(bytes(range(5)))
'0001020304'
>>> humanize_bytes(bytes(range(32)))
'0001..1e1f'
A loose wrapper around humanize_bytes
that is typed specifically for the
eth_typing.Hash32
type.
>>> from eth_utils import humanize_hash
>>> humanize_hash(bytes(range(32)))
'0001..1e1f'
Returns a concise representation of the provided sequence of integer values.
>>> from eth_utils import humanize_integer_sequence
>>> humanize_integer_sequence((1, 2, 3, 4))
'1-4'
>>> humanize_integer_sequence((1, 2, 3, 4, 6, 8, 9, 10))
'1-4|6|8-10'
Returns the provided IPFS uri, with the middle segment of the hash replaced by an ellipsis, only showing the first and last four characters of the hash.
>>> from eth_utils import humanize_ipfs_uri
>>> humanize_ipfs_uri('ipfs://QmTKB75Y73zhNbD3Y73xeXGjYrZHmaXXNxoZqGCagu7r8u')
'ipfs://QmTK..7r8u'
Returns a human-friendly form of units given an amount of wei.
>>> from eth_utils import humanize_wei
>>> humanize_wei(0)
'0 wei'
>>> humanize_wei(1000000000000000000000)
'1000 ether'
>>> humanize_wei(9876543)
'0.009876543 gwei'
This API is similar to the standard library logging.getLogger
however, the
logger it returns will be an instance of the provided logger_class
. If
logger_class
is not provided this returns an instance of whatever the
current default logger class is set on the logging
.
>>> import logging
>>> from eth_utils import get_logger
>>> logger = get_logger('my_application')
>>> assert logger.name == 'my_application'
>>> assert isinstance(logger, logging.getLoggerClass())
Like get_logger
except that it always returns an instance of ExtendedDebugLogger
>>> from eth_utils import get_extended_debug_logger, ExtendedDebugLogger
>>> logger = get_extended_debug_logger('my_application')
>>> assert logger.name == 'my_application'
>>> assert isinstance(logger, ExtendedDebugLogger), type(logger)
Classes which inherit from this class will have an instance of a logger
available on the attribute logger
>>> from eth_utils import HasLogger
>>> class MyClass(HasLogger):
... pass
...
>>> MyClass.logger.debug("This works")
>>> instance = MyClass()
>>> instance.logger.debug("This also works")
The name
of the logger instance is derived from the __qualname__
for
the class.
Warning
This class will not behave nicely with the standard library
typing.Generic
. If you need to create a Generic
class then you'll
need to assign your logging instances manually.
A subclass of logging.Logger
which exposes a debug2
function which can
be used to log a message at the DEBUG2
log level.
Note
This class works fine on its own but will produce cleaner logs if you make
sure to call eth_utils.setup_DEBUG2_logging
at least once before
issuing any debug2
level logs.
Same as the HasLogger
class except the logger it exposes is an instance of
ExtendedDebugLogger
Installs the DEBUG2
level to the standard library logging
module which
uses the numeric level of 8
. This includes adding it to the known levels
as well as providing a logging.DEBUG2
convenience property on the logging
module.
This function is purely for convenience. You can use ExtendedDebugLogger
without this, though your logs will be printed with the label 'Level 8'
.
>>> from eth_utils import setup_DEBUG2_logging
>>> import logging
>>> logging.getLevelName(8)
'Level 8'
>>> setup_DEBUG2_logging()
>>> logging.getLevelName(8)
'DEBUG2'
>>> logging.DEBUG2
8
Note
This function is idempotent
This is the metaclass which is responsible for adding the logger instance to the class. It exposes two additional APIs.
HasLoggerMeta.replace_logger_class(cls: logging.Logger)
Returns a new metaclass which will use the provided logger class.
HasLoggerMeta.meta_compat(other: type)
Returns a new metaclass that derives from both metaclasses. This is useful when working in conjunction with
abc.ABC
ortyping.Generic
.
This metaclass uses the ExtendedDebugLogger class, derived from HasLoggerMeta.replace_logger_class(ExtendedDebugLogger).
Import a variable/class name for a module given the dotted_path string.
Raises an ImportError if the module could not be found.
>>> from eth_utils import import_string
>>> import_string("eth_utils.decorators.combomethod")
<class 'eth_utils.decorators.combomethod'>
The :class:`~eth-utils.Networks` class provides methods to obtain network names and
other metadata given a chain_id
.
Returns the Network
for the given chain_id
int value.
>>> from eth_utils import network
>>> network.network_from_chain_id(1)
Network(chain_id=1, name='Ethereum Mainnet', shortName='eth', symbol=<ChainId.ETH: 1>)
>>> network.network_from_chain_id(2)
Network(chain_id=2, name='Expanse Network', shortName='exp', symbol=<ChainId.EXP: 2>)
>>> network.network_from_chain_id(100)
Network(chain_id=100, name='Gnosis', shortName='gno', symbol=<ChainId.GNO: 100>)
Returns the name
of the Network
with the given chain_id
int value.
>>> from eth_utils import network
>>> network.name_from_chain_id(1)
'Ethereum Mainnet'
>>> network.name_from_chain_id(2)
'Expanse Network'
>>> network.name_from_chain_id(100)
'Gnosis'
Returns the short_name
of the Network
with the given chain_id
int value.
>>> from eth_utils import network
>>> network.short_name_from_chain_id(1)
'eth'
>>> network.short_name_from_chain_id(2)
'exp'
>>> network.short_name_from_chain_id(100)
'gno'
Returns value
clamped within the inclusive range defined by [lower_bound,
upper_bound]
. The value can be any number type that supports <
and >
comparisons against the provided bounds.
>>> from eth_utils import clamp
>>> clamp(5, 7, 4)
5
>>> clamp(5, 7, 5)
5
>>> clamp(5, 7, 6)
6
>>> clamp(5, 7, 7)
7
>>> clamp(5, 7, 8)
7
Returns True
if value
is of type bool
>>> from eth_utils import is_boolean
>>> is_boolean(True)
True
>>> is_boolean(False)
True
>>> is_boolean(1)
False
Returns True
if value
is a byte string or a byte array.
>>> from eth_utils import is_bytes
>>> is_bytes('abcd')
False
>>> is_bytes(b'abcd')
True
>>> is_bytes(bytearray((1, 2, 3)))
True
Returns True
if value
is a mapping type.
>>> from eth_utils import is_dict
>>> is_dict({'a': 1})
True
>>> is_dict([1, 2, 3])
False
Returns True
if value
is an integer
>>> from eth_utils import is_integer
>>> is_integer(0)
True
>>> is_integer(1)
True
>>> is_integer('1')
False
>>> is_integer(1.1)
False
Returns True
if value
is a non-string sequence such as a
sequence (such as a list or tuple).
>>> from eth_utils import is_list_like
>>> is_list_like('abcd')
False
>>> is_list_like([])
True
>>> is_list_like(tuple())
True
Returns True
if value
is a non-string sequence such as a list.
>>> from eth_utils import is_list
>>> is_list('abcd')
False
>>> is_list([])
True
>>> is_list(tuple())
False
Returns True
if value
is a non-string sequence such as a tuple.
>>> from eth_utils import is_tuple
>>> is_tuple('abcd')
False
>>> is_tuple([])
False
>>> is_tuple(tuple())
True
Returns True
if value
is None
>>> from eth_utils import is_null
>>> is_null(None)
True
>>> is_null(False)
False
Returns True
if value
is numeric
>>> from eth_utils import is_number
>>> is_number(1)
True
>>> is_number(1.1)
True
>>> is_number('1')
False
>>> from decimal import Decimal
>>> is_number(Decimal('1'))
True
Returns True
if value
is of any string type.
>>> from eth_utils import is_string
>>> is_string('abcd')
True
>>> is_string(b'abcd')
True
>>> is_string(bytearray((1, 2, 3)))
True
Returns True
if value
is a text string.
>>> from eth_utils import is_text
>>> is_text(u'abcd')
True
>>> is_text(b'abcd')
False
>>> is_text(bytearray((1, 2, 3)))
False