Python conversion from binary string to hexadecimal

Question

How can I perform a conversion of a binary string to the corresponding hex value in Python?

I have 0000 0100 1000 1101 and I want to get 048D I'm using Python 2.6.

Solution 1

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.

Solution 2

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

Solution 3

Use python's binascii module

import binascii

binFile = open('somebinaryfile.exe','rb')
binaryData = binFile.read(8)

print binascii.hexlify(binaryData)

Solution 4

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))

Solution 5

Using no messy concatenations and padding :

'{:0{width}x}'.format(int(temp,2), width=4)

Will give a hex representation with padding preserved

View more solutions

Comments

[Ignacio Vazquez-Abrams]

This fails to preserve leading 0s.

[SilentGhost]

you don't need list comprehension there

[Eli Bendersky]

@Ignacio, you're right, but I don't think the OP asked about that. In any case, ++ to your answer for pointing that out.

[Eli Bendersky]

@SO should really add per-language coloring. Here it thinks // is a C++ comment and grays out everything following. // in Python isn't a comment, but truncating integer division

[John Machin]

@Eli: the OP specifically said he wanted 048d i.e. wants leading zero, DOESN'T want 0x

[ghostdog74]

so what's the problem? Its still in Python 2.6

[John Machin]

It's still in 2.X for the benefit of people who were using it in 1.X. string.atoi() is according to the 2.6 docs """Deprecated since version 2.0: Use the int() built-in function.""" and is not present in 3.X. The 2.X implementation of string.atoi() calls int(). There is no good reason for telling some newcomer that string.atoi() even exists let alone telling them to use it instead of telling them to use int().

[Andrei]

This works only for 2-byte numbers, while Ignacio's answer works for any length.

[Andrei]

You need to replace spaces before conversion.

[Andrei]

You still need to replace spaces if any.

[Andrei]

Brilliant answer. I am surprised why it's not upvoted/accepted yet.

[Dennis]

This may not preserve the leading zeroes, but it's much more readable than the clever hacks below.

[user253751]

@Dennis the first line is just cleaning up the binary string. The second line formats it as a hexadecimal string, padded to (len(bstr) + 3) // 4 hex digits, which is number of bits / 4 rounded up, i.e. the number of hex digits required. The last part of the second line parses the binary string to a number, because the %X format specifier is for numbers not binary strings.

[Michal aka Miki]

Where is bin_value_to_hex_string?

[Djunzu]

What is the equivalent in Python 3? Using "".format()