5 Best Ways to Convert a List of Ints to Hex in Python

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💡 Problem Formulation: How can one convert a list of integers to their corresponding hexadecimal representation in Python? This is a common task when dealing with low-level data processing, such as network packet analysis or binary file manipulations. For instance, converting [16, 255, 43, 88] to their hexadecimal equivalents should yield ['0x10', '0xff', '0x2b', '0x58'].

Method 1: Using the hex Function

The built-in Python function hex() takes an integer and returns its hexadecimal representation as a string. To convert a list of integers to hex, you can simply use a list comprehension that applies hex() to each integer in the list.

Here’s an example:

int_list = [16, 255, 43, 88]
hex_list = [hex(n) for n in int_list]
print(hex_list)

Output:

['0x10', '0xff', '0x2b', '0x58']

This code snippet creates a new list, hex_list, which contains the hexadecimal representations of the integers from the original int_list. The list comprehension iterates over each integer, converting it to hex using the hex() function.

Method 2: Using map with hex

The map() function can be used to apply the hex function to every item in a list. This is a functional programming approach to converting a list of integers to their hexadecimal representations.

Here’s an example:

int_list = [16, 255, 43, 88]
hex_list = list(map(hex, int_list))
print(hex_list)

Output:

['0x10', '0xff', '0x2b', '0x58']

Using the map() function, this code applies the hex function to each element of int_list. The result is then converted back to a list using the list() constructor.

Method 3: Using a Loop

For those who prefer a more explicit approach, a for loop can be used to iterate through each integer in the list, convert it to hexadecimal, and append it to a new list.

Here’s an example:

int_list = [16, 255, 43, 88]
hex_list = []
for n in int_list:
    hex_list.append(hex(n))
print(hex_list)

Output:

['0x10', '0xff', '0x2b', '0x58']

This snippet manually iterates over the int_list, converts each integer to hex using hex(), and appends the resulting string to hex_list.

Method 4: Using format

The format function in Python allows more control over the representation, such as padding or capitalization. Here’s how you can use it to convert integers to hex.

Here’s an example:

int_list = [16, 255, 43, 88]
hex_list = ['0x{:x}'.format(n) for n in int_list]
print(hex_list)

Output:

['0x10', '0xff', '0x2b', '0x58']

This method uses list comprehension with the format function, where {:x} indicates hexadecimal lowercase formatting. Each integer in int_list is formatted as a hexadecimal string and all are collected into hex_list.

Bonus One-Liner Method 5: Lambda with map

Combining a lambda function with map() allows for a one-liner solution that applies a custom formatting function to each integer in the list.

Here’s an example:

int_list = [16, 255, 43, 88]
hex_list = list(map(lambda n: f'0x{n:x}', int_list))
print(hex_list)

Output:

['0x10', '0xff', '0x2b', '0x58']

This compact code snippet uses a lambda function to format each integer to hexadecimal format prefixed with ‘0x’. The map() function iterates through int_list and returns an iterator that the list() function converts to a list of hex values.

Summary/Discussion

  • Method 1: Using hex Function. Simple and direct. Uses built-in functionality. Does not allow for formatting options.
  • Method 2: Using map with hex. More functional programming oriented. Clean and concise. Less readable for those unfamiliar with map.
  • Method 3: Using a Loop. Explicit and easy to understand. Verbose compared to other methods. Best for complex transformations.
  • Method 4: Using format. Offers formatting control. Slightly more complex syntax. Ideal for custom hex representation.
  • Bonus One-Liner Method 5: Lambda with map. Compact and powerful. Can be difficult to read. Handy for quick conversions.