Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.9/dist-packages/bitstring/methods.py: 18%

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 

8from bitstring.bitstore import BitStore 

9from bitstring.bitstore_helpers import bitstore_from_token 

10 

11 

12def pack(fmt: Union[str, List[str]], *values, **kwargs) -> BitStream: 

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

14 

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

16 describing how to create the BitStream. 

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

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

19 format string will be replaced with their given value. 

20 

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

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

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

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

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

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

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

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

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

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

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

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

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

34 'bin:1' : single bit binary string 

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

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

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

38 'bytes:10' : 10 bytes as a bytes object 

39 'bool' : 1 bit as a bool 

40 'pad:3' : 3 zero bits as padding 

41 

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

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

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

45 

46 """ 

47 tokens = [] 

48 if isinstance(fmt, str): 

49 fmt = [fmt] 

50 try: 

51 for f_item in fmt: 

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

53 tokens.extend(tkns) 

54 except ValueError as e: 

55 raise CreationError(*e.args) 

56 value_iter = iter(values) 

57 bsl: List[BitStore] = [] 

58 try: 

59 for name, length, value in tokens: 

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

61 value = kwargs.get(value, value) 

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

63 length = kwargs.get(length, length) 

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

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

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

67 continue 

68 if length is not None: 

69 length = int(length) 

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

71 # Take the next value from the ones provided 

72 value = next(value_iter) 

73 if name == 'bits': 

74 value = bitstring.bits.Bits(value) 

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

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

77 bsl.append(value._bitstore) 

78 continue 

79 bsl.append(bitstore_from_token(name, length, value)) 

80 except StopIteration: 

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

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

83 

84 try: 

85 next(value_iter) 

86 except StopIteration: 

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

88 s = BitStream() 

89 if bitstring.options.lsb0: 

90 bsl.reverse() 

91 for b in bsl: 

92 s._bitstore += b 

93 return s 

94 

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