Python:如何将可变长度的前导零添加到二进制字符串中

Question

我希望将前导零添加到my_string='01001010'，以确保最小的'length'位字符串，其中length>=len(my_string(

Answer 1

我定义了一个函数，它将未知基数的整数(十六进制、十进制、八进制、二进制等(转换为位。这些位用零填充到用户定义长度的最小值，必要时溢出到额外的位，而不填充零。

def convert_bits(obj, **kwargs):

if 'base' in kwargs:
base = int(kwargs.get('base'))
else:
base = 10
if 'location' in kwargs:
location = int(kwargs.get('location'))
else:
location = -1
if 'subroutine' in kwargs:
subroutine = str(kwargs.get('subroutine'))
else:
subroutine = ''
try:
if 'length' in kwargs:
length = int(kwargs.get('length'))
bitstream = "{0:0{1:}b}".format(int(str(obj), base), length)           
if len(bitstream) != length:
raise OverflowException(
bitstream=bitstream, length=length, location=location, 
subroutine=subroutine)
else:
bitstream = "{0:0b}".format(int(str(obj), base))
except Exception as e:
print(f"Exception in convert_bits method: {e}n")
return bitstream
class OverflowException(Exception):
def __init__(self, **kwargs):
if kwargs:
try:
self.length = int(kwargs.get('length'))
self.bitstream = str(kwargs.get('bitstream'))
self.location = int(kwargs.get('location'))
self.subroutine = str(kwargs.get('subroutine'))
except:
print('exception intializing OverflowExceptionn')
self.length = 0
self.bitstream = ''
def __str__(self):
if self.bitstream and self.length:
if self.subroutine and self.location is not None:
return f"OVERFLOW! Bitstream has {len(self.bitstream)} bits, exceeding {self.length} at index:{self.location} in {self.subroutine}"
else:
print('No location / subroutine found!n')
return f"OVERFLOW! Bitstream has {len(self.bitstream)} bits, exceeding {self.length}"
else:
return f"OVERFLOW!"