BinField 0.6.1

binfield

Python binfield implementation for binary data manipulation.

Pros:

• Free software: Apache license

• Open Source: https://github.com/penguinolog/binfield

• Self-documented code: docstrings with types in comments

• Tested: see bages on top

• Support miltiple Python versions:

Python 2.7
Python 3.4
Python 3.5
Python 3.6
PyPy

Usage

Not mapped objects could be created simply from BinField class:

bf = BinField(42)

Data with fixed size should be created as new class (type):

class TwoBytes(BinField):
    _size_ = 16  # Size in bits


bf = TwoBytes(42)
2 == len(bf)  # Length is in bytes for easier conversion to bytes

Also binary mask could be attached and data will be always conform with it:

class MyBinField(BinField):
    _mask_ = 0b11
    _size_ = 8


bf = MyBinField(5)
0b001 == bf  # Mask was applied and 0b101 & 0b011 = 0b001

Mapped objects is also should be created as new class (type):

class MyBinField(BinField):
    first = 0  # Single bit
    two_bits = [1, 3]  # Also could be mapped as tuple and slice
    _mask_ = 0b1011


bf = MyBinField(0b1101)
0b1001 == bf
4 == bf._size_  # Size is generated during creation from mask
0b01 == bf.two_bits._mask_  # Mask is inherited from parent object
MyBinField.first == 0  # Getter was generated from mapping
MyBinField.two_bits == slice(1, 3)  # Slices is mapped during class generation

Nested mapping is supported:

class MyBinField(BinField):
    first = 0  # Single bit
    two_bits = [1, 3]  # Also could be mapped as tuple and slice
    nested = {
        '_index_': [3, 8],  # Index is mandatory, it should be slice, list or tuple
        'nested_bit': 0,  # In nested objects use relative indexing
        'nested_bits': [1, 3]
    }
    # Nested objects could contain less indexed area, than block size,
    # but mask will be calculated from outer level indexes only.
    MyBinField.nested_bits == slice(1, 3)  # Nested objects is exposed as indexes only at class property.


bf = MyBinField(0xFF)
0b00011111 == bf.nested
# Nested received (generated as all bits in range) mask from top
# and size from slice
1 == bf.nested.nested_bit  # __getitem__ and properties is available
bf.nested.nested_bit = 0  # property has setters
0b11110111 == bf  # Change on nested is returned to main object

Note: negative indexes is not supported by design!

Testing

The main test mechanism for the package binfield is using tox. Test environments available:

pep8
py27
py34
py35
py36
pypy
pylint

CI systems

For code checking several CI systems is used in parallel:

1. Travis CI: is used for checking: PEP8, pylint, bandit, installation possibility and unit tests. Also it’s publishes coverage on coveralls.

2. coveralls: is used for coverage display.