Python conversion from binary string to hexadecimal

int given base 2 and then hex:

>>> int('010110', 2)
22
>>> hex(int('010110', 2))
'0x16'
>>> 

>>> hex(int('0000010010001101', 2))
'0x48d'

The doc of int:

int(x[, base]) -> integer

Convert a string or number to an integer, if possible.  A floating

point argument will be truncated towards zero (this does not include a string representation of a floating point number!) When converting a string, use the optional base. It is an error to supply a base when converting a non-string. If base is zero, the proper base is guessed based on the string content. If the argument is outside the integer range a long object will be returned instead.

The doc of hex:

hex(number) -> string

Return the hexadecimal representation of an integer or long

integer.

bstr = '0000 0100 1000 1101'.replace(' ', '')
hstr = '%0*X' % ((len(bstr) + 3) // 4, int(bstr, 2))

Converting Binary into hex without ignoring leading zeros:

You could use the format() built-in function like this:

"{0:0>4X}".format(int("0000010010001101", 2))

On python3 using the hexlify function:

import binascii
def bin2hex(str1):
    bytes_str = bytes(str1, 'utf-8')
    return binascii.hexlify(bytes_str)

a="abc123"
c=bin2hex(a)
c

Will give you back:

b'616263313233'

and you can get the string of it like:

c.decode('utf-8')

gives:

'616263313233'

I would do:

dec_str = format(int('0000010010001101', 2),'x')
dec_str.rjust(4,'0')

Result: '048d'

To convert binary string to hexadecimal string, we don't need any external libraries. Use formatted string literals (known as f-strings). This feature was added in python 3.6 (PEP 498)

>>> bs = '0000010010001101'
>>> hexs = f'{int(bs, 2):X}'
>>> print(hexs)
>>> '48D'

If you want hexadecimal strings in small-case, use small "x" as follows

f'{int(bs, 2):x}'

Where bs inside f-string is a variable which contains binary strings assigned prior

f-strings are lost more useful and effective. They are not being used at their full potential.

Assuming they are grouped by 4 and separated by whitespace. This preserves the leading 0.

b = '0000 0100 1000 1101'
h = ''.join(hex(int(a, 2))[2:] for a in b.split())

>>> import string
>>> s="0000 0100 1000 1101"
>>> ''.join([ "%x"%string.atoi(bin,2) for bin in s.split() ]  )
'048d'
>>>

or

>>> s="0000 0100 1000 1101"
>>> hex(string.atoi(s.replace(" ",""),2))
'0x48d'

 x = int(input("press 1 for dec to oct,bin,hex \n press 2 for bin to dec,hex,oct \n press 3 for oct to bin,hex,dec \n press 4 for hex to bin,dec,oct \n"))


   if x is 1:

  decimal =int(input('Enter the decimal number: '))

  print(bin(decimal),"in binary.")
 print(oct(decimal),"in octal.")
    print(hex(decimal),"in hexadecimal.")

      if x is 2:

       binary = input("Enter number in Binary Format: ");

  decimal = int(binary, 2);
  print(binary,"in Decimal =",decimal);
  print(binary,"in Hexadecimal =",hex(decimal));
  print(binary,"in octal =",oct(decimal));

    if x is 3:

      octal = input("Enter number in Octal Format: ");

      decimal = int(octal, 8);
      print(octal,"in Decimal =",decimal);
      print(octal,"in Hexadecimal =",hex(decimal));
      print(octal,"in Binary =",bin(decimal));

          if x is 4:

         hex = input("Enter number in hexa-decimal Format: ");

      decimal = int(hex, 16);
        print(hex,"in Decimal =",decimal);
      print(hex,"in octal =",oct(decimal));
        print(hex,"in Binary =",bin(decimal));