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Are there any canned Python methods to convert an Integer (or Long) into a binary string in Python?
There are a myriad of dec2bin() functions out on Google... But I was hoping I could use a built-in function / library.
Python's string format method can take a format spec.
>>> "{0:b}".format(37)
'100101'
Format spec docs for Python 2
Format spec docs for Python 3
If you're looking for bin() as an equivalent to hex(), it was added in python 2.6.
Example:
>>> bin(10)
'0b1010'
Python actually does have something already built in for this, the ability to do operations such as '{0:b}'.format(42), which will give you the bit pattern (in a string) for 42, or 101010.
For a more general philosophy, no language or library will give its user base everything that they desire. If you're working in an environment that doesn't provide exactly what you need, you should be collecting snippets of code as you develop to ensure you never have to write the same thing twice. Such as, for example, the pseudo-code:
define intToBinString, receiving intVal:
if intVal is equal to zero:
return "0"
set strVal to ""
while intVal is greater than zero:
if intVal is odd:
prefix "1" to strVal
else:
prefix "0" to strVal
divide intVal by two, rounding down
return strVal
which will construct your binary string based on the decimal value. Just keep in mind that's a generic bit of pseudo-code which may not be the most efficient way of doing it though, with the iterations you seem to be proposing, it won't make much difference. It's really just meant as a guideline on how it could be done.
The general idea is to use code from (in order of preference):
the language or built-in libraries.
third-party libraries with suitable licenses.
your own collection.
something new you need to write (and save in your own collection for later).
If you want a textual representation without the 0b-prefix, you could use this:
get_bin = lambda x: format(x, 'b')
print(get_bin(3))
>>> '11'
print(get_bin(-3))
>>> '-11'
When you want a n-bit representation:
get_bin = lambda x, n: format(x, 'b').zfill(n)
>>> get_bin(12, 32)
'00000000000000000000000000001100'
>>> get_bin(-12, 32)
'-00000000000000000000000000001100'
Alternatively, if you prefer having a function:
def get_bin(x, n=0):
"""
Get the binary representation of x.
Parameters
----------
x : int
n : int
Minimum number of digits. If x needs less digits in binary, the rest
is filled with zeros.
Returns
-------
str
"""
return format(x, 'b').zfill(n)
I am surprised there is no mention of a nice way to accomplish this using formatting strings that are supported in Python 3.6 and higher. TLDR:
>>> number = 1
>>> f'0b{number:08b}'
'0b00000001'
Longer story
This is functionality of formatting strings available from Python 3.6:
>>> x, y, z = 1, 2, 3
>>> f'{x} {y} {2*z}'
'1 2 6'
You can request binary as well:
>>> f'{z:b}'
'11'
Specify the width:
>>> f'{z:8b}'
' 11'
Request zero padding:
f'{z:08b}'
'00000011'
And add common prefix to signify binary number:
>>> f'0b{z:08b}'
'0b00000011'
You can also let Python add the prefix for you but I do not like it so much as the version above because you have to take the prefix into width consideration:
>>> f'{z:#010b}'
'0b00000011'
More info is available in official documentation on Formatted string literals and Format Specification Mini-Language.
As a reference:
def toBinary(n):
return ''.join(str(1 & int(n) >> i) for i in range(64)[::-1])
This function can convert a positive integer as large as 18446744073709551615, represented as string '1111111111111111111111111111111111111111111111111111111111111111'.
It can be modified to serve a much larger integer, though it may not be as handy as "{0:b}".format() or bin().
This is for python 3 and it keeps the leading zeros !
print(format(0, '08b'))
A simple way to do that is to use string format, see this page.
>> "{0:b}".format(10)
'1010'
And if you want to have a fixed length of the binary string, you can use this:
>> "{0:{fill}8b}".format(10, fill='0')
'00001010'
If two's complement is required, then the following line can be used:
'{0:{fill}{width}b}'.format((x + 2**n) % 2**n, fill='0', width=n)
where n is the width of the binary string.
one-liner with lambda:
>>> binary = lambda n: '' if n==0 else binary(n/2) + str(n%2)
test:
>>> binary(5)
'101'
EDIT:
but then :(
t1 = time()
for i in range(1000000):
binary(i)
t2 = time()
print(t2 - t1)
# 6.57236599922
in compare to
t1 = time()
for i in range(1000000):
'{0:b}'.format(i)
t2 = time()
print(t2 - t1)
# 0.68017411232
As the preceding answers mostly used format(),
here is an f-string implementation.
integer = 7
bit_count = 5
print(f'{integer:0{bit_count}b}')
Output:
00111
For convenience here is the python docs link for formatted string literals: https://docs.python.org/3/reference/lexical_analysis.html#f-strings.
Summary of alternatives:
n=42
assert "-101010" == format(-n, 'b')
assert "-101010" == "{0:b}".format(-n)
assert "-101010" == (lambda x: x >= 0 and str(bin(x))[2:] or "-" + str(bin(x))[3:])(-n)
assert "0b101010" == bin(n)
assert "101010" == bin(n)[2:] # But this won't work for negative numbers.
Contributors include John Fouhy, Tung Nguyen, mVChr, Martin Thoma. and Martijn Pieters.
>>> format(123, 'b')
'1111011'
For those of us who need to convert signed integers (range -2**(digits-1) to 2**(digits-1)-1) to 2's complement binary strings, this works:
def int2bin(integer, digits):
if integer >= 0:
return bin(integer)[2:].zfill(digits)
else:
return bin(2**digits + integer)[2:]
This produces:
>>> int2bin(10, 8)
'00001010'
>>> int2bin(-10, 8)
'11110110'
>>> int2bin(-128, 8)
'10000000'
>>> int2bin(127, 8)
'01111111'
you can do like that :
bin(10)[2:]
or :
f = str(bin(10))
c = []
c.append("".join(map(int, f[2:])))
print c
Using numpy pack/unpackbits, they are your best friends.
Examples
--------
>>> a = np.array([[2], [7], [23]], dtype=np.uint8)
>>> a
array([[ 2],
[ 7],
[23]], dtype=uint8)
>>> b = np.unpackbits(a, axis=1)
>>> b
array([[0, 0, 0, 0, 0, 0, 1, 0],
[0, 0, 0, 0, 0, 1, 1, 1],
[0, 0, 0, 1, 0, 1, 1, 1]], dtype=uint8)
Yet another solution with another algorithm, by using bitwise operators.
def int2bin(val):
res=''
while val>0:
res += str(val&1)
val=val>>1 # val=val/2
return res[::-1] # reverse the string
A faster version without reversing the string.
def int2bin(val):
res=''
while val>0:
res = chr((val&1) + 0x30) + res
val=val>>1
return res
numpy.binary_repr(num, width=None)
Examples from the documentation link above:
>>> np.binary_repr(3)
'11'
>>> np.binary_repr(-3)
'-11'
>>> np.binary_repr(3, width=4)
'0011'
The two’s complement is returned when the input number is negative and width is specified:
>>> np.binary_repr(-3, width=3)
'101'
>>> np.binary_repr(-3, width=5)
'11101'
The accepted answer didn't address negative numbers, which I'll cover.
In addition to the answers above, you can also just use the bin and hex functions. And in the opposite direction, use binary notation:
>>> bin(37)
'0b100101'
>>> 0b100101
37
But with negative numbers, things get a bit more complicated. The question doesn't specify how you want to handle negative numbers.
Python just adds a negative sign so the result for -37 would be this:
>>> bin(-37)
'-0b100101'
In computer/hardware binary data, negative signs don't exist. All we have is 1's and 0's. So if you're reading or producing binary streams of data to be processed by other software/hardware, you need to first know the notation being used.
One notation is sign-magnitude notation, where the first bit represents the negative sign, and the rest is the actual value. In that case, -37 would be 0b1100101 and 37 would be 0b0100101. This looks like what python produces, but just add a 0 or 1 in front for positive / negative numbers.
More common is Two's complement notation, which seems more complicated and the result is very different from python's string formatting. You can read the details in the link, but with an 8bit signed integer -37 would be 0b11011011 and 37 would be 0b00100101.
Python has no easy way to produce these binary representations. You can use numpy to turn Two's complement binary values into python integers:
>>> import numpy as np
>>> np.int8(0b11011011)
-37
>>> np.uint8(0b11011011)
219
>>> np.uint8(0b00100101)
37
>>> np.int8(0b00100101)
37
But I don't know an easy way to do the opposite with builtin functions. The bitstring package can help though.
>>> from bitstring import BitArray
>>> arr = BitArray(int=-37, length=8)
>>> arr.uint
219
>>> arr.int
-37
>>> arr.bin
'11011011'
>>> BitArray(bin='11011011').int
-37
>>> BitArray(bin='11011011').uint
219
Python 3.6 added a new string formatting approach called formatted string literals or “f-strings”.
Example:
name = 'Bob'
number = 42
f"Hello, {name}, your number is {number:>08b}"
Output will be 'Hello, Bob, your number is 00001010!'
A discussion of this question can be found here - Here
Unless I'm misunderstanding what you mean by binary string I think the module you are looking for is struct
n=input()
print(bin(n).replace("0b", ""))
def binary(decimal) :
otherBase = ""
while decimal != 0 :
otherBase = str(decimal % 2) + otherBase
decimal //= 2
return otherBase
print binary(10)
output:
1010
Here is the code I've just implemented. This is not a method but you can use it as a ready-to-use function!
def inttobinary(number):
if number == 0:
return str(0)
result =""
while (number != 0):
remainder = number%2
number = number/2
result += str(remainder)
return result[::-1] # to invert the string
Calculator with all neccessary functions for DEC,BIN,HEX:
(made and tested with Python 3.5)
You can change the input test numbers and get the converted ones.
# CONVERTER: DEC / BIN / HEX
def dec2bin(d):
# dec -> bin
b = bin(d)
return b
def dec2hex(d):
# dec -> hex
h = hex(d)
return h
def bin2dec(b):
# bin -> dec
bin_numb="{0:b}".format(b)
d = eval(bin_numb)
return d,bin_numb
def bin2hex(b):
# bin -> hex
h = hex(b)
return h
def hex2dec(h):
# hex -> dec
d = int(h)
return d
def hex2bin(h):
# hex -> bin
b = bin(h)
return b
## TESTING NUMBERS
numb_dec = 99
numb_bin = 0b0111
numb_hex = 0xFF
## CALCULATIONS
res_dec2bin = dec2bin(numb_dec)
res_dec2hex = dec2hex(numb_dec)
res_bin2dec,bin_numb = bin2dec(numb_bin)
res_bin2hex = bin2hex(numb_bin)
res_hex2dec = hex2dec(numb_hex)
res_hex2bin = hex2bin(numb_hex)
## PRINTING
print('------- DECIMAL to BIN / HEX -------\n')
print('decimal:',numb_dec,'\nbin: ',res_dec2bin,'\nhex: ',res_dec2hex,'\n')
print('------- BINARY to DEC / HEX -------\n')
print('binary: ',bin_numb,'\ndec: ',numb_bin,'\nhex: ',res_bin2hex,'\n')
print('----- HEXADECIMAL to BIN / HEX -----\n')
print('hexadec:',hex(numb_hex),'\nbin: ',res_hex2bin,'\ndec: ',res_hex2dec,'\n')
Somewhat similar solution
def to_bin(dec):
flag = True
bin_str = ''
while flag:
remainder = dec % 2
quotient = dec / 2
if quotient == 0:
flag = False
bin_str += str(remainder)
dec = quotient
bin_str = bin_str[::-1] # reverse the string
return bin_str
here is simple solution using the divmod() fucntion which returns the reminder and the result of a division without the fraction.
def dectobin(number):
bin = ''
while (number >= 1):
number, rem = divmod(number, 2)
bin = bin + str(rem)
return bin
Here's yet another way using regular math, no loops, only recursion. (Trivial case 0 returns nothing).
def toBin(num):
if num == 0:
return ""
return toBin(num//2) + str(num%2)
print ([(toBin(i)) for i in range(10)])
['', '1', '10', '11', '100', '101', '110', '111', '1000', '1001']
To calculate binary of numbers:
print("Binary is {0:>08b}".format(16))
To calculate the Hexa decimal of a number:
print("Hexa Decimal is {0:>0x}".format(15))
To Calculate all the binary no till 16::
for i in range(17):
print("{0:>2}: binary is {0:>08b}".format(i))
To calculate Hexa decimal no till 17
for i in range(17):
print("{0:>2}: Hexa Decimal is {0:>0x}".format(i))
##as 2 digit is enogh for hexa decimal representation of a number
try:
while True:
p = ""
a = input()
while a != 0:
l = a % 2
b = a - l
a = b / 2
p = str(l) + p
print(p)
except:
print ("write 1 number")
I found a method using matrix operation to convert decimal to binary.
import numpy as np
E_mat = np.tile(E,[1,M])
M_order = pow(2,(M-1-np.array(range(M)))).T
bindata = np.remainder(np.floor(E_mat /M_order).astype(np.int),2)
Eis input decimal data,M is the binary orders. bindata is output binary data, which is in a format of 1 by M binary matrix.
I'd simply like to convert a base-2 binary number string into an int, something like this:
>>> '11111111'.fromBinaryToInt()
255
Is there a way to do this in Python?
You use the built-in int() function, and pass it the base of the input number, i.e. 2 for a binary number:
>>> int('11111111', 2)
255
Here is documentation for Python 2, and for Python 3.
Just type 0b11111111 in python interactive interface:
>>> 0b11111111
255
Another way to do this is by using the bitstring module:
>>> from bitstring import BitArray
>>> b = BitArray(bin='11111111')
>>> b.uint
255
Note that the unsigned integer (uint) is different from the signed integer (int):
>>> b.int
-1
Your question is really asking for the unsigned integer representation; this is an important distinction.
The bitstring module isn't a requirement, but it has lots of performant methods for turning input into and from bits into other forms, as well as manipulating them.
Using int with base is the right way to go. I used to do this before I found int takes base also. It is basically a reduce applied on a list comprehension of the primitive way of converting binary to decimal ( e.g. 110 = 2**0 * 0 + 2 ** 1 * 1 + 2 ** 2 * 1)
add = lambda x,y : x + y
reduce(add, [int(x) * 2 ** y for x, y in zip(list(binstr), range(len(binstr) - 1, -1, -1))])
If you wanna know what is happening behind the scene, then here you go.
class Binary():
def __init__(self, binNumber):
self._binNumber = binNumber
self._binNumber = self._binNumber[::-1]
self._binNumber = list(self._binNumber)
self._x = [1]
self._count = 1
self._change = 2
self._amount = 0
print(self._ToNumber(self._binNumber))
def _ToNumber(self, number):
self._number = number
for i in range (1, len (self._number)):
self._total = self._count * self._change
self._count = self._total
self._x.append(self._count)
self._deep = zip(self._number, self._x)
for self._k, self._v in self._deep:
if self._k == '1':
self._amount += self._v
return self._amount
mo = Binary('101111110')
Here's another concise way to do it not mentioned in any of the above answers:
>>> eval('0b' + '11111111')
255
Admittedly, it's probably not very fast, and it's a very very bad idea if the string is coming from something you don't have control over that could be malicious (such as user input), but for completeness' sake, it does work.
A recursive Python implementation:
def int2bin(n):
return int2bin(n >> 1) + [n & 1] if n > 1 else [1]
If you are using python3.6 or later you can use f-string to do the
conversion:
Binary to decimal:
>>> print(f'{0b1011010:#0}')
90
>>> bin_2_decimal = int(f'{0b1011010:#0}')
>>> bin_2_decimal
90
binary to octal hexa and etc.
>>> f'{0b1011010:#o}'
'0o132' # octal
>>> f'{0b1011010:#x}'
'0x5a' # hexadecimal
>>> f'{0b1011010:#0}'
'90' # decimal
Pay attention to 2 piece of information separated by colon.
In this way, you can convert between {binary, octal, hexadecimal, decimal} to {binary, octal, hexadecimal, decimal} by changing right side of colon[:]
:#b -> converts to binary
:#o -> converts to octal
:#x -> converts to hexadecimal
:#0 -> converts to decimal as above example
Try changing left side of colon to have octal/hexadecimal/decimal.
For large matrix (10**5 rows and up) it is better to use a vectorized matmult. Pass in all rows and cols in one shot. It is extremely fast. There is no looping in python here. I originally designed it for converting many binary columns like 0/1 for like 10 different genre columns in MovieLens into a single integer for each example row.
def BitsToIntAFast(bits):
m,n = bits.shape
a = 2**np.arange(n)[::-1] # -1 reverses array of powers of 2 of same length as bits
return bits # a
For the record to go back and forth in basic python3:
a = 10
bin(a)
# '0b1010'
int(bin(a), 2)
# 10
eval(bin(a))
# 10
I've been reading up a lot on stuct.pack and hex and the like.
I am trying to convert a decimal to hexidecimal with 2-bytes. Reverse the hex bit order, then convert it back into decimal.
I'm trying to follow these steps...in python
Convert the decimal value **36895** to the equivalent 2-byte hexadecimal value:
**0x901F**
Reverse the order of the 2 hexadecimal bytes:
**0x1F90**
Convert the resulting 2-byte hexadecimal value to its decimal equivalent:
**8080**
Bit shifting to swap upper/lower eight bits:
>>> x = 36895
>>> ((x << 8) | (x >> 8)) & 0xFFFF
8080
Packing and unpacking unsigned short(H) with opposite endianness(<>):
>>> struct.unpack('<H',struct.pack('>H',x))[0]
8080
Convert 2-byte little-endian to big-endian...
>>> int.from_bytes(x.to_bytes(2,'little'),'big')
8080
To convert from decimal to hex, use:
dec = 255
print hex(dec)[2:-1]
That will output the hex value for 255.
To convert back to decimal, use
hex = 1F90
print int(hex, 16)
That would output the decimal value for 1F90.
You should be able to reverse the bytes using:
hex = "901F"
hexbyte1 = hex[0] + hex[1]
hexbyte2 = hex[2] + hex[3]
newhex = hexbyte2 + hexbyte1
print newhex
and this would output 1F90. Hope this helps!
Keep in mind that 'hex'(base 16 0-9 and a-f) and 'decimal'(0-9) are just constructs for humans to represent numbers. It's all bits to the machine.
The python hex(int) function produces a hex 'string' . If you want to convert it back to decimal:
>>> x = 36895
>>> s = hex(x)
>>> s
'0x901f'
>>> int(s, 16) # interpret s as a base-16 number
Print formatting also works with strings.
# Get the hex digits, without the leading '0x'
hex_str = '%04X' % (36895)
# Reverse the bytes using string slices.
# hex_str[2:4] is, oddly, characters 2 to 3.
# hex_str[0:2] is characters 0 to 1.
str_to_convert = hex_str[2:4] + hex_str[0:2]
# Read back the number in base 16 (hex)
reversed = int(str_to_convert, 16)
print(reversed) # 8080!
My approach
import binascii
n = 36895
reversed_hex = format(n, 'x').decode('hex')[::-1]
h = binascii.hexlify(reversed_hex)
print int(h, 16)
or one line
print int(hex(36895)[2:].decode('hex')[::-1].encode('hex'), 16)
print int(format(36895, 'x').decode('hex')[::-1].encode('hex'), 16)
print int(binascii.hexlify(format(36895, 'x').decode('hex')[::-1]), 16)
or with bytearray
import binascii
n = 36895
b = bytearray.fromhex(format(n, 'x'))
b.reverse()
print int(binascii.hexlify(b), 16)
I have ABC123EFFF.
I want to have 001010101111000001001000111110111111111111 (i.e. binary repr. with, say, 42 digits and leading zeroes).
How?
For solving the left-side trailing zero problem:
my_hexdata = "1a"
scale = 16 ## equals to hexadecimal
num_of_bits = 8
bin(int(my_hexdata, scale))[2:].zfill(num_of_bits)
It will give 00011010 instead of the trimmed version.
import binascii
binary_string = binascii.unhexlify(hex_string)
Read
binascii.unhexlify
Return the binary data represented by the hexadecimal string specified as the parameter.
Convert hex to binary
I have ABC123EFFF.
I want to have 001010101111000001001000111110111111111111 (i.e. binary
repr. with, say, 42 digits and leading zeroes).
Short answer:
The new f-strings in Python 3.6 allow you to do this using very terse syntax:
>>> f'{0xABC123EFFF:0>42b}'
'001010101111000001001000111110111111111111'
or to break that up with the semantics:
>>> number, pad, rjust, size, kind = 0xABC123EFFF, '0', '>', 42, 'b'
>>> f'{number:{pad}{rjust}{size}{kind}}'
'001010101111000001001000111110111111111111'
Long answer:
What you are actually saying is that you have a value in a hexadecimal representation, and you want to represent an equivalent value in binary.
The value of equivalence is an integer. But you may begin with a string, and to view in binary, you must end with a string.
Convert hex to binary, 42 digits and leading zeros?
We have several direct ways to accomplish this goal, without hacks using slices.
First, before we can do any binary manipulation at all, convert to int (I presume this is in a string format, not as a literal):
>>> integer = int('ABC123EFFF', 16)
>>> integer
737679765503
alternatively we could use an integer literal as expressed in hexadecimal form:
>>> integer = 0xABC123EFFF
>>> integer
737679765503
Now we need to express our integer in a binary representation.
Use the builtin function, format
Then pass to format:
>>> format(integer, '0>42b')
'001010101111000001001000111110111111111111'
This uses the formatting specification's mini-language.
To break that down, here's the grammar form of it:
[[fill]align][sign][#][0][width][,][.precision][type]
To make that into a specification for our needs, we just exclude the things we don't need:
>>> spec = '{fill}{align}{width}{type}'.format(fill='0', align='>', width=42, type='b')
>>> spec
'0>42b'
and just pass that to format
>>> bin_representation = format(integer, spec)
>>> bin_representation
'001010101111000001001000111110111111111111'
>>> print(bin_representation)
001010101111000001001000111110111111111111
String Formatting (Templating) with str.format
We can use that in a string using str.format method:
>>> 'here is the binary form: {0:{spec}}'.format(integer, spec=spec)
'here is the binary form: 001010101111000001001000111110111111111111'
Or just put the spec directly in the original string:
>>> 'here is the binary form: {0:0>42b}'.format(integer)
'here is the binary form: 001010101111000001001000111110111111111111'
String Formatting with the new f-strings
Let's demonstrate the new f-strings. They use the same mini-language formatting rules:
>>> integer = 0xABC123EFFF
>>> length = 42
>>> f'{integer:0>{length}b}'
'001010101111000001001000111110111111111111'
Now let's put this functionality into a function to encourage reusability:
def bin_format(integer, length):
return f'{integer:0>{length}b}'
And now:
>>> bin_format(0xABC123EFFF, 42)
'001010101111000001001000111110111111111111'
Aside
If you actually just wanted to encode the data as a string of bytes in memory or on disk, you can use the int.to_bytes method, which is only available in Python 3:
>>> help(int.to_bytes)
to_bytes(...)
int.to_bytes(length, byteorder, *, signed=False) -> bytes
...
And since 42 bits divided by 8 bits per byte equals 6 bytes:
>>> integer.to_bytes(6, 'big')
b'\x00\xab\xc1#\xef\xff'
bin(int("abc123efff", 16))[2:]
>>> bin( 0xABC123EFFF )
'0b1010101111000001001000111110111111111111'
Use Built-in format() function and int() function
It's simple and easy to understand. It's little bit simplified version of Aaron answer
int()
int(string, base)
format()
format(integer, # of bits)
Example
# w/o 0b prefix
>> format(int("ABC123EFFF", 16), "040b")
1010101111000001001000111110111111111111
# with 0b prefix
>> format(int("ABC123EFFF", 16), "#042b")
0b1010101111000001001000111110111111111111
# w/o 0b prefix + 64bit
>> format(int("ABC123EFFF", 16), "064b")
0000000000000000000000001010101111000001001000111110111111111111
See also this answer
"{0:020b}".format(int('ABC123EFFF', 16))
Here's a fairly raw way to do it using bit fiddling to generate the binary strings.
The key bit to understand is:
(n & (1 << i)) and 1
Which will generate either a 0 or 1 if the i'th bit of n is set.
import binascii
def byte_to_binary(n):
return ''.join(str((n & (1 << i)) and 1) for i in reversed(range(8)))
def hex_to_binary(h):
return ''.join(byte_to_binary(ord(b)) for b in binascii.unhexlify(h))
print hex_to_binary('abc123efff')
>>> 1010101111000001001000111110111111111111
Edit: using the "new" ternary operator this:
(n & (1 << i)) and 1
Would become:
1 if n & (1 << i) or 0
(Which TBH I'm not sure how readable that is)
This is a slight touch up to Glen Maynard's solution, which I think is the right way to do it. It just adds the padding element.
def hextobin(self, hexval):
'''
Takes a string representation of hex data with
arbitrary length and converts to string representation
of binary. Includes padding 0s
'''
thelen = len(hexval)*4
binval = bin(int(hexval, 16))[2:]
while ((len(binval)) < thelen):
binval = '0' + binval
return binval
Pulled it out of a class. Just take out self, if you're working in a stand-alone script.
I added the calculation for the number of bits to fill to Onedinkenedi's solution. Here is the resulting function:
def hextobin(h):
return bin(int(h, 16))[2:].zfill(len(h) * 4)
Where 16 is the base you're converting from (hexadecimal), and 4 is how many bits you need to represent each digit, or log base 2 of the scale.
Replace each hex digit with the corresponding 4 binary digits:
1 - 0001
2 - 0010
...
a - 1010
b - 1011
...
f - 1111
hex --> decimal then decimal --> binary
#decimal to binary
def d2b(n):
bStr = ''
if n < 0: raise ValueError, "must be a positive integer"
if n == 0: return '0'
while n > 0:
bStr = str(n % 2) + bStr
n = n >> 1
return bStr
#hex to binary
def h2b(hex):
return d2b(int(hex,16))
# Python Program - Convert Hexadecimal to Binary
hexdec = input("Enter Hexadecimal string: ")
print(hexdec," in Binary = ", end="") # end is by default "\n" which prints a new line
for _hex in hexdec:
dec = int(_hex, 16) # 16 means base-16 wich is hexadecimal
print(bin(dec)[2:].rjust(4,"0"), end="") # the [2:] skips 0b, and the
Just use the module coden (note: I am the author of the module)
You can convert haxedecimal to binary there.
Install using pip
pip install coden
Convert
a_hexadecimal_number = "f1ff"
binary_output = coden.hex_to_bin(a_hexadecimal_number)
The converting Keywords are:
hex for hexadeimal
bin for binary
int for decimal
_to_ - the converting keyword for the function
So you can also format:
e. hexadecimal_output = bin_to_hex(a_binary_number)
Another way:
import math
def hextobinary(hex_string):
s = int(hex_string, 16)
num_digits = int(math.ceil(math.log(s) / math.log(2)))
digit_lst = ['0'] * num_digits
idx = num_digits
while s > 0:
idx -= 1
if s % 2 == 1: digit_lst[idx] = '1'
s = s / 2
return ''.join(digit_lst)
print hextobinary('abc123efff')
The binary version of ABC123EFFF is actually 1010101111000001001000111110111111111111
For almost all applications you want the binary version to have a length that is a multiple of 4 with leading padding of 0s.
To get this in Python:
def hex_to_binary( hex_code ):
bin_code = bin( hex_code )[2:]
padding = (4-len(bin_code)%4)%4
return '0'*padding + bin_code
Example 1:
>>> hex_to_binary( 0xABC123EFFF )
'1010101111000001001000111110111111111111'
Example 2:
>>> hex_to_binary( 0x7123 )
'0111000100100011'
Note that this also works in Micropython :)
i have a short snipped hope that helps :-)
input = 'ABC123EFFF'
for index, value in enumerate(input):
print(value)
print(bin(int(value,16)+16)[3:])
string = ''.join([bin(int(x,16)+16)[3:] for y,x in enumerate(input)])
print(string)
first i use your input and enumerate it to get each symbol. then i convert it to binary and trim from 3th position to the end. The trick to get the 0 is to add the max value of the input -> in this case always 16 :-)
the short form ist the join method. Enjoy.
HEX_TO_BINARY_CONVERSION_TABLE = {
'0': '0000',
'1': '0001',
'2': '0010',
'3': '0011',
'4': '0100',
'5': '0101',
'6': '0110',
'7': '0111',
'8': '1000',
'9': '1001',
'a': '1010',
'b': '1011',
'c': '1100',
'd': '1101',
'e': '1110',
'f': '1111'}
def hex_to_binary(hex_string):
binary_string = ""
for character in hex_string:
binary_string += HEX_TO_BINARY_CONVERSION_TABLE[character]
return binary_string
when I time hex_to_binary("123ade")
%timeit hex_to_binary("123ade")
here is the result:
316 ns ± 2.52 ns per loop
Alternatively, you could use "join" method:
def hex_to_binary_join(hex_string):
hex_array=[]
for character in hex_string:
hex_array.append(HEX_TO_BINARY_CONVERSION_TABLE[character])
return "".join(hex_array)
I timed this too:
%timeit hex_to_binary_join("123ade")
397 ns ± 4.64 ns per loop
a = raw_input('hex number\n')
length = len(a)
ab = bin(int(a, 16))[2:]
while len(ab)<(length * 4):
ab = '0' + ab
print ab
import binascii
hexa_input = input('Enter hex String to convert to Binary: ')
pad_bits=len(hexa_input)*4
Integer_output=int(hexa_input,16)
Binary_output= bin(Integer_output)[2:]. zfill(pad_bits)
print(Binary_output)
"""zfill(x) i.e. x no of 0 s to be padded left - Integers will overwrite 0 s
starting from right side but remaining 0 s will display till quantity x
[y:] where y is no of output chars which need to destroy starting from left"""
def conversion():
e=raw_input("enter hexadecimal no.:")
e1=("a","b","c","d","e","f")
e2=(10,11,12,13,14,15)
e3=1
e4=len(e)
e5=()
while e3<=e4:
e5=e5+(e[e3-1],)
e3=e3+1
print e5
e6=1
e8=()
while e6<=e4:
e7=e5[e6-1]
if e7=="A":
e7=10
if e7=="B":
e7=11
if e7=="C":
e7=12
if e7=="D":
e7=13
if e7=="E":
e7=14
if e7=="F":
e7=15
else:
e7=int(e7)
e8=e8+(e7,)
e6=e6+1
print e8
e9=1
e10=len(e8)
e11=()
while e9<=e10:
e12=e8[e9-1]
a1=e12
a2=()
a3=1
while a3<=1:
a4=a1%2
a2=a2+(a4,)
a1=a1/2
if a1<2:
if a1==1:
a2=a2+(1,)
if a1==0:
a2=a2+(0,)
a3=a3+1
a5=len(a2)
a6=1
a7=""
a56=a5
while a6<=a5:
a7=a7+str(a2[a56-1])
a6=a6+1
a56=a56-1
if a5<=3:
if a5==1:
a8="000"
a7=a8+a7
if a5==2:
a8="00"
a7=a8+a7
if a5==3:
a8="0"
a7=a8+a7
else:
a7=a7
print a7,
e9=e9+1
no=raw_input("Enter your number in hexa decimal :")
def convert(a):
if a=="0":
c="0000"
elif a=="1":
c="0001"
elif a=="2":
c="0010"
elif a=="3":
c="0011"
elif a=="4":
c="0100"
elif a=="5":
c="0101"
elif a=="6":
c="0110"
elif a=="7":
c="0111"
elif a=="8":
c="1000"
elif a=="9":
c="1001"
elif a=="A":
c="1010"
elif a=="B":
c="1011"
elif a=="C":
c="1100"
elif a=="D":
c="1101"
elif a=="E":
c="1110"
elif a=="F":
c="1111"
else:
c="invalid"
return c
a=len(no)
b=0
l=""
while b<a:
l=l+convert(no[b])
b+=1
print l
I have a non-negative int and I would like to efficiently convert it to a big-endian string containing the same data. For example, the int 1245427 (which is 0x1300F3) should result in a string of length 3 containing three characters whose byte values are 0x13, 0x00, and 0xf3.
My ints are on the scale of 35 (base-10) digits.
How do I do this?
In Python 3.2+, you can use int.to_bytes:
If you don't want to specify the size
>>> n = 1245427
>>> n.to_bytes((n.bit_length() + 7) // 8, 'big') or b'\0'
b'\x13\x00\xf3'
If you don't mind specifying the size
>>> (1245427).to_bytes(3, byteorder='big')
b'\x13\x00\xf3'
You can use the struct module:
import struct
print(struct.pack('>I', your_int))
'>I' is a format string. > means big endian and I means unsigned int. Check the documentation for more format chars.
This is fast and works for small and (arbitrary) large ints:
def Dump(n):
s = '%x' % n
if len(s) & 1:
s = '0' + s
return s.decode('hex')
print repr(Dump(1245427)) #: '\x13\x00\xf3'
Probably the best way is via the built-in struct module:
>>> import struct
>>> x = 1245427
>>> struct.pack('>BH', x >> 16, x & 0xFFFF)
'\x13\x00\xf3'
>>> struct.pack('>L', x)[1:] # could do it this way too
'\x13\x00\xf3'
Alternatively -- and I wouldn't usually recommend this, because it's mistake-prone -- you can do it "manually" by shifting and the chr() function:
>>> x = 1245427
>>> chr((x >> 16) & 0xFF) + chr((x >> 8) & 0xFF) + chr(x & 0xFF)
'\x13\x00\xf3'
Out of curiosity, why do you only want three bytes? Usually you'd pack such an integer into a full 32 bits (a C unsigned long), and use struct.pack('>L', 1245427) but skip the [1:] step?
def tost(i):
result = []
while i:
result.append(chr(i&0xFF))
i >>= 8
result.reverse()
return ''.join(result)
Single-source Python 2/3 compatible version based on #pts' answer:
#!/usr/bin/env python
import binascii
def int2bytes(i):
hex_string = '%x' % i
n = len(hex_string)
return binascii.unhexlify(hex_string.zfill(n + (n & 1)))
print(int2bytes(1245427))
# -> b'\x13\x00\xf3'
The shortest way, I think, is the following:
import struct
val = 0x11223344
val = struct.unpack("<I", struct.pack(">I", val))[0]
print "%08x" % val
This converts an integer to a byte-swapped integer.
Using the bitstring module:
>>> bitstring.BitArray(uint=1245427, length=24).bytes
'\x13\x00\xf3'
Note though that for this method you need to specify the length in bits of the bitstring you are creating.
Internally this is pretty much the same as Alex's answer, but the module has a lot of extra functionality available if you want to do more with your data.
Very easy with pwntools , the tools created for software hacking
(Un-ironically, I stumbled across this thread and tried solutions here, until I realised there exists conversion functionality in pwntools)
import pwntools
x2 = p32(x1)