How To Convert a String to Hex in Python

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

Python Strings Example - Iterate Th...
Python Strings Example - Iterate Through A String

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.

Using encode()

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())

Output:

436f6e76657274696e6720737472696e6720696e746f2068657820666f726d61742e

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)

Output:

0x569

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)

Output:

0x64533490

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())

Output:

0x436f6e76657274696e6720737472696e6720696e746f2068657820666f726d6174

Using binascii

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))

Output:

b'48656c6c6f'

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.

print(hex(ord("a")))
print(hex(ord("T")))

Output:

0x61
0x54

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())

Output:

“hello”

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'))

Output:

“hello”.

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)

Output:

“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'))

Output:

“string”

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) 

Output:

100

Conclusion

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.

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