Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/bitstring/methods.py: 20%

1from __future__ import annotations 

2 

3import bitstring 

4from bitstring.bitstream import BitStream 

5from bitstring.utils import tokenparser 

6from bitstring.exceptions import CreationError 

7from typing import Union, List 

8 

9MutableBitStore = bitstring.bitstore.MutableBitStore 

10helpers = bitstring.bitstore_helpers 

11common_helpers = bitstring.bitstore_common_helpers 

12 

13 

14def pack(fmt: Union[str, List[str]], *values, **kwargs) -> BitStream: 

15 """Pack the values according to the format string and return a new BitStream. 

16 

17 fmt -- A single string or a list of strings with comma separated tokens 

18 describing how to create the BitStream. 

19 values -- Zero or more values to pack according to the format. 

20 kwargs -- A dictionary or keyword-value pairs - the keywords used in the 

21 format string will be replaced with their given value. 

22 

23 Token examples: 'int:12' : 12 bits as a signed integer 

24 'uint:8' : 8 bits as an unsigned integer 

25 'float:64' : 8 bytes as a big-endian float 

26 'intbe:16' : 2 bytes as a big-endian signed integer 

27 'uintbe:16' : 2 bytes as a big-endian unsigned integer 

28 'intle:32' : 4 bytes as a little-endian signed integer 

29 'uintle:32' : 4 bytes as a little-endian unsigned integer 

30 'floatle:64': 8 bytes as a little-endian float 

31 'intne:24' : 3 bytes as a native-endian signed integer 

32 'uintne:24' : 3 bytes as a native-endian unsigned integer 

33 'floatne:32': 4 bytes as a native-endian float 

34 'hex:80' : 80 bits as a hex string 

35 'oct:9' : 9 bits as an octal string 

36 'bin:1' : single bit binary string 

37 'ue' / 'uie': next bits as unsigned exp-Golomb code 

38 'se' / 'sie': next bits as signed exp-Golomb code 

39 'bits:5' : 5 bits as a bitstring object 

40 'bytes:10' : 10 bytes as a bytes object 

41 'bool' : 1 bit as a bool 

42 'pad:3' : 3 zero bits as padding 

43 

44 >>> s = pack('uint:12, bits', 100, '0xffe') 

45 >>> t = pack(['bits', 'bin:3'], s, '111') 

46 >>> u = pack('uint:8=a, uint:8=b, uint:55=a', a=6, b=44) 

47 

48 """ 

49 tokens = [] 

50 if isinstance(fmt, str): 

51 fmt = [fmt] 

52 try: 

53 for f_item in fmt: 

54 _, tkns = tokenparser(f_item, tuple(sorted(kwargs.keys()))) 

55 tokens.extend(tkns) 

56 except ValueError as e: 

57 raise CreationError(*e.args) 

58 value_iter = iter(values) 

59 bsl: List[BitStore] = [] 

60 try: 

61 for name, length, value in tokens: 

62 # If the value is in the kwd dictionary then it takes precedence. 

63 value = kwargs.get(value, value) 

64 # If the length is in the kwd dictionary then use that too. 

65 length = kwargs.get(length, length) 

66 # Also if we just have a dictionary name then we want to use it 

67 if name in kwargs and length is None and value is None: 

68 bsl.append(BitStream(kwargs[name])._bitstore) 

69 continue 

70 if length is not None: 

71 length = int(length) 

72 if value is None and name != 'pad': 

73 # Take the next value from the ones provided 

74 value = next(value_iter) 

75 if name == 'bits': 

76 value = bitstring.bits.Bits(value) 

77 if length is not None and length != len(value): 

78 raise CreationError(f"Token with length {length} packed with value of length {len(value)}.") 

79 bsl.append(value._bitstore) 

80 continue 

81 bsl.append(common_helpers.bitstore_from_token(name, length, value)) 

82 except StopIteration: 

83 raise CreationError(f"Not enough parameters present to pack according to the " 

84 f"format. {len(tokens)} values are needed.") 

85 

86 try: 

87 next(value_iter) 

88 except StopIteration: 

89 # Good, we've used up all the *values. 

90 s = BitStream() 

91 if bitstring.options.lsb0: 

92 bsl.reverse() 

93 for b in bsl: 

94 s._bitstore += b 

95 return s 

96 

97 raise CreationError(f"Too many parameters present to pack according to the format. Only {len(tokens)} values were expected.")