Byte string to int python

How to Convert bytes to int in Python

To convert bytes to int in Python, you can use the int.from_bytes() method. This method takes bytes, byteorder, signed, * as parameters and returns the integer represented by the given array of bytes.

Syntax

int.from_bytes(bytes, byteorder, *, signed=False)

Parameters

bytes: It is a byte object.

byteorder: It determines the order of representation of the integer value. The byteorder can have values as either “little,” where the most significant bit is stored at the end, or “big”, where MSB is stored at the start and LSB at the end.

signed: It has a False default value. It indicates whether to represent 2’s complement of a number.

Return Value

It returns the integer represented by the given array of bytes.

Example 1: How to Use int.from_bytes() Method

# Declaring byte value byte_val = b'\x21\x19' # Converting to int int_val = int.from_bytes(byte_val, "big") # printing int equivalent print(int_val)

You can see that we passed byteorder = big. The byteorder argument determines the byte order used to represent the integer. If the byteorder is “little“, the most significant byte is at the beginning of the byte array.

Example 2: Passing byteorder = “little”

If the byteorder is “little“, the most significant byte is at the end of the byte array.

# Declaring byte value byte_val = b'\x11\x21' # Converting to int int_val = int.from_bytes(byte_val, "little") # printing int equivalent print(int_val)

Example 3: Passing signed=True

The int.from_bytes() method also accepts the signed argument. By default, its value is False.

Let’s another example and pass signed = True and see the output.

# Declaring byte value byte_val = b'\xfc\x00' # Converting to int int_val = int.from_bytes(byte_val, "big", signed=True) # printing int equivalent print(int_val)

I hope you found the answer you are looking for, which is for converting bytes to integers in Python.

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Convert Bytes to Int in Python

In this post, we will see how to convert Bytes to Int in Python.

Normally, the data is stored in the storage in bytes format. In this article, we will discuss how we can convert data given as bytes to integer or int data types in python. For this, we will use the int.from_bytes() method.

How to Convert Bytes to Int in Python?

We will convert bytes to int using the int.from_bytes() method. The syntax for the from_bytes() method is as follows.

• The parameter bytes takes the bytes object that has to be converted to int as the input argument.
• The byteorder parameter is used to define the byte order of the bytes object that is passed as the first input argument.
  • If “ big ” is given as an input argument to the byteorder parameter, the first byte from the beginning of the bytes object is considered to be the most significant byte.
  • If “ little ” is given as an input argument to the byteorder parameter, the first byte from the end of the bytes object is considered to be the most significant byte.
  • To use the byte order of the machine on which the program is being run, you can use the sys.byteorder attribute using the sys module.

  How to Convert Bytes to Signed Int in Python?

  To convert the bytes object to a signed int, we will set the parameter signed to True in the from_bytes() method. To observe this, let us first create a bytes object from an integer using the int.to_bytes() method. The to_bytes() method takes the integer value as the first input argument, the length of the output bytes object as the second input argument and the byteorder as the third input argument. After execution, it returns the bytes object. Then we can convert the bytes object to int using the from_bytes() method as shown below.

  Источник

  Convert Bytes to Int in Python 2.7 and 3.x

  Craving a more dynamic learning experience? we’ve crafted a comprehensive YouTube video complementing this article embedded at the end of this page!

  

  Bytes data type has the value with a range from 0 to 255 (0x00 to 0xFF). One byte has 8 bits; that’s why its maximum value is 0xFF. In some circumstances, you need to convert bytes or bytes array to integers for further data processing. This short article introduces methods to convert byte to int in Python, like the struct.unpack method in Python 2.7 and int.from_bytes() in Python 3.x.

  Python 2.7 Bytes Data Type

  There is no built-in bytes data type in Python 2.7 version. Keyword byte is identical to str .

  bytearray is used to define a bytes or byte array object.

  >>> byteExample1 = bytearray([1]) >>> byteExample1 bytearray(b'\x01') >>> byteExample2 = bytearray([1,2,3]) >>> byteExample2 bytearray(b'\x01\x02\x03') 

  Convert Byte to Int in Python 2.7

  Python internal module struct could convert binary data (bytes) to integers. It could convert bytes or actually strings in Python 2.7 and integers in a bidirectional way.

  struct.unpack(fmt, string)  Convert the string according to the given format `fmt` to integers. The result is a tuple even if there is only one item inside. 

  struct Examples: Convert Byte to Int in Python 2.7

  import struct testBytes = b'\x00\x01\x00\x02' testResult = struct.unpack('>HH', testBytes) print testResult 

  1. > indicates the binary data is big-endian , or in other words, the data is ordered from the big end (most significant bit). For example, \x00\0x1 means \x00 is the high byte, and \x01 is the low byte.
  2. HH means there are two objects of H types in the bytes string. H represents an unsigned short integer that takes 2 bytes.

  You could get different results from the same string if the assigned data format is different.

  >>> testResult = struct.unpack(', testBytes) >>> testResult (256, 512) 

  >>> testResult = struct.unpack(', testBytes) >>> testResult (0, 1, 0, 2) 

  B means the data is unsigned char taking 1 byte. Hence, \x00\x01\x00\x02 will be converted to 4 values of unsigned char , but not 2 values of unsigned short anymore.

  The data length represented by the format string shall be the same as the given data; otherwise, it reports an error.

  >>> testResult = struct.unpack(', b'\x00\x01\x00\x02')  Traceback (most recent call last):  File "", line 1, in module>  testResult = struct.unpack(', b'\x00\x01\x00\x02') error: unpack requires a string argument of length 3 

  You could check the struct module’s official document to get more information on format strings.

  Python 3 Bytes Data Type

  bytes is a built-in data type in Python 3; therefore, you could define bytes directly using the bytes keyword.

  >>> testByte = bytes(18) >>> type(testByte) class 'bytes'> 

  You could also directly define a bytes or bytes array like below.

  >>> testBytes = b'\x01\x21\31\41' >>> type(testBytes) class 'bytes'> 

  Convert Bytes to Int in Python 3

  Besides the struct module as already introduced in Python 2.7, you could also use a new Python 3 built-in int method to do the bytes-to-integers conversions, that is, the int.from_bytes() method.

  int.from_bytes() Examples: Convert Byte to Int

  >>> testBytes = b'\xF1\x10' >>> int.from_bytes(testBytes, byteorder='big') 61712 

  The byteorder option is similar to struct.unpack() format byte order definition.

  int.from_bytes() has a third option signed to assign the integer type to be signed or unsigned .

  >>> testBytes = b'\xF1\x10' >>> int.from_bytes(testBytes, byteorder='big', signed=True) -3824 

  Use [] When Bytes Is unsigned char

  If the format of data has the format of unsigned char containing only one byte, you could directly use object index to access and get the integer of the data.

  >>> testBytes = b'\xF1\x10' >>> testBytes[0] 241 >>> testBytes[1] 16 

  Founder of DelftStack.com. Jinku has worked in the robotics and automotive industries for over 8 years. He sharpened his coding skills when he needed to do the automatic testing, data collection from remote servers and report creation from the endurance test. He is from an electrical/electronics engineering background but has expanded his interest to embedded electronics, embedded programming and front-/back-end programming.

  Related Article — Python Bytes

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  Python bytes to int

  

  This python 3 tutorial help to convert bytes to an integer. Python 3.2 has introduced a function int.from_bytes() , that helps to convert bytes to an integer. It returns immutable bytes object initialized with the given size and data. The bytes() is a built-in method that use to create bytes.

  Python bytes to int

  Let’s convert bytes to int into python using int.from_bytes() method. A byte value can be interchanged to an int value using the int.from_bytes() function. It returns the integer represented of the given array of bytes.

  The syntax

  int.from_bytes(bytes, byteorder, *, signed=False)

  • bytes: This is a byte object.
  • byteorder: It help to determines the order of representation of the integer value. .
  • signed: The default value is False. It indicates whether two’s complement is used to represent the integer..

  Python Code to Convert Bytes to INT

  # Declaring byte value byte_val = b'\x03\x45' # Converting bytes to int int_val = int.from_bytes(byte_val, "big") # print output print(int_val)

  Convert Bytes to INT by byteorder = “little”

  Let’s pass byteorder = “little” into int.from_bytes () method:

  # Declaring byte value byte_val = b'\x03\x45' # Converting bytes to int int_val = int.from_bytes(byte_val, "little") # print output print(int_val)

  Output:
  17667

  Convert Bytes to INT by Passing signed=True

  The int.from_bytes() method also accepts the signed argument. its default value is False. We’ll pass signed = True into this method.

  # Declaring byte value byte_val = b'\xcd\x45' # Converting bytes to int int_val = int.from_bytes(byte_val, "big", signed=True) # print output print(int_val)

  Output:
  -12987

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