In this tutorial you will learn how to convert a string to hex in Python, and a hex to string in Python.
Table of Contents
- String to Hex
- Hex to String
- Hex to integer
String to Hex
There exist different methods of converting a string into a hex in python.
Hexadecimal values have a base of 16, and the prefix 0x is used to display any given string in hexadecimal format. Strings can be converted into a hexadecimal format in one of the following ways.
The encode() method is one of the most popular methods of converting any string into hex format. In this method, firstly string is converted into bytes using the encode() method, and then the resulting value is converted into hex format using the hex method.
# Converting a string into bytes using encode method string = "Converting string into hex format.".encode('utf-8') # Using the hex method to convert the bytes into hexadecimal format string.hex() # Printing the hexadecimal value of the given string print(string.hex())
Using ast library method
In this method, the ast library is used to convert a given string into hex format. Firstly, literal_eval is imported from the ast library. Secondly, a string is created with the prefix 0x because this method only accepts the characters with 0x prefixes.
After making the string, it is passed through the literal_eval method. This method gives the integer format of the given string, which can then be passed through the hex method to obtain the hex value of the given string.
# Importing literal_eval from ast library from ast import literal_eval string = "0x569" # Converting a string into an integer using literal_eval method str_into_int = literal_eval(string) # Passing integer value through hex method hex_value = hex(str_into_int) # Printing the hex value print(hex_value)
Using the hex() method
hex() method is generally used to convert the hexadecimal integers string value to hexadecimal values. In this method, a hexadecimal integer is passed as a parameter through the hex() method, and it provides the hexadecimal value of the given string.
For this method to work, the given string should be converted into a hexadecimal integer value, and then the integer value should be passed through the hex function.
Any given string can be converted into a hexadecimal integer value by passing it through the int method along with the base 16 as a parameter.
hex_string = "0x64533490" # Passing the string through the int method with base 16 to convert it into an integer int_format = int(hex_string, 16) # Passing the integer value through the hex method hex_format = hex(int_format) # Print the hexadecimal format of the integer print(hex_format)
Sometimes you will encounter syntax errors and typeErrors because the hex method only accepts integer values and if you pass a string through it, then it will give an error.
Another fastest way of converting a string into a hexadecimal value is using b with hex method. In this method, “b” is placed at the beginning of a string which indicates the conversion of the string into bytes.
Generally, hex values start with 0x, so the prefix “0x” can be placed with the output to get the hexadecimal value of any given string.
print("0x"+ converting string into hex format".hex())
In this method, binascii library is used to convert any given string into hex format.
Firstly, we import the binascii module. Secondly, the given string is converted into a byte object using b.
Finally, the byte object is passed through the hexlify method, which gives the hex value of the given string.
# Importing library import binascii # Using b to convert the string into bytes string = b"Hello" # Using the hexlify method to convert bytes into hexadecimal format print(binascii.hexlify(string))
If the purpose is just to convert the strings of the alphabet into the hexadecimal format, then the ord method along with the hex method can be applied to get the hex value of any given alphabet.
Hex to String
Hexadecimal string and ASCII values in python are interchangeable and different methods can be used to convert a given hex value to a string and vice versa.
Using decode() method
In this method, bytearray.decode (encoding, error) takes the byte array as an input and then decodes it using the encoding specified as an argument.
In order to decode a hex value, the first step is to convert the hex string into a byte string and then apply the bytearray.decode() method.
To convert hex string into bytes, bytearray.fromhex() method can be used.
# Converting hex value to a string string = "68656c6c6f" # Using fromhex method from bytearray to convert hex value to byte byte_array = bytearray.fromhex(string) # Using decode method to convert bytes into ASCII string byte_array.decode() # Printing the string print(byte_array.decode())
Using codecs.decode() method
In this method, codecs module is imported to convert the hex values into strings. This method requires a codecs library for conversion, which contains base classes for encoding and decoding data, commonly used in Unicode text-based files.
This method is similar to the decode() method. The only difference is that along with encoding and error arguments, this method also takes the objects as input arguments.
Error argument in this method is used to handle errors during the execution of the program. The codecs.decodes() method in this case returns a byte object, which is then converted into the string using the str() method.
# Importing the codecs library import codecs # The hexadecimal string string = "68656c6c6f" # Converting the hex string into bytes using the codecs.decode() method binary_str = codecs.decode(string, "hex") # Converting the resultant byte into the string str(binary_str,'utf-8') # Printing out the string print(str(binary_str,'utf-8'))
By appending hex to a string
In this method, a hex value is converted into a string and then combined with the other string. It’s an efficient one-liner that reads in a single hex value at a time converts it to an ASCII character and appends it to the end of the variable.
This repeats until the conversion is complete.
def hex_to_str(hex): if hex[:2] == '0x': hex = hex[2:] str_value = bytes.fromhex(hex).decode('utf-8') return str_value hex_value = '0x737472696e67' print(hex_value) string = 'Converting hex to ' + hex_to_str('737472696e67') print(string)
“Converting hex to string”.
Using the binascii module
It is one of the simplest ways of converting a hex value to a string format. In this method, the unhexlify method of the binascii module is used for the conversion of hex value to string format.
# Importing binascii module import binascii # Using unhexlify method from binascii module binascii.unhexlify('737472696e67') # Printing the output print(binascii.unhexlify('737472696e67'))
Hex to integer
The int constructor
int() can be used for conversion between a hex string and an integer. The int constructor takes the string and the base you are converting from and will give the corresponding integer value of given hex.
hex_value = "0x64" x = int(hex_value, 0) print(x)
There are many ways to convert strings to hexadecimals, and hexadecimals to strings in Python. A practical use case for these conversion methods could be obtaining character codes being read in from files.