Given a hex string, i.e., a string of hexadecimal digits like so:
You want to convert a batch of k hex digits to an integer. For example with k=2, you obtain the following batches of two hex digits each:
01 ff a8 71 35 af fc d4 5d ee be
Now, convert each of those pairs of hex digits to an integer:
[1, 255, 168, 113, 53, 175, 252, 212, 93, 238, 190]
Note that if you’re looking to convert such a hex string to NumPy array, check out this tutorial instead.
The following one-liner iterates over each
k-th position of the hex string and bundles together
k subsequent hex digits. It converts each of those hex digits to an integer using
int(..., base=16) in a list comprehension statement.
[int(hex_str[i:i+k], base=16) for i in range(0, len(hex_str), k)]
Here’s the minimal code example:
def hex_to_int_list(hex_str, k): ''' Aggregates bundles of k subsequent hex digits to one integer. Yields a list of ints.''' return [int(hex_str[i:i+k], base=16) for i in range(0, len(hex_str), k)] print(hex_to_int_list('01ffa87135affcd45deebe', 2)) # [1, 255, 168, 113, 53, 175, 252, 212, 93, 238, 190]
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If not, keep reading for the not-so-concise multi-liner solution. 🙂
You can use a
for loop to iterate over the
k-th indices using the
range() function like before.
def hex_to_int_list(hex_str, k): ''' Aggregates bundles of k subsequent hex digits to one integer. Yields a list of ints.''' lst =  for i in range(0, len(hex_str), k): x = hex_str[i:i+k] x_int = int(x, base=16) lst.append(x_int) return lst print(hex_to_int_list('01ffa87135affcd45deebe', 2)) # [1, 255, 168, 113, 53, 175, 252, 212, 93, 238, 190]
You use slicing
hex_str[i:i+k] to batch
k digits at a time to a substring and convert it to an integer.
You use the list
append() method to add one integer at a time to the list of ints.
You return a list of integers. If you want to return an array of integers, simply convert the list to a NumPy array using the
np.array(lst) function call:
import numpy as np def hex_to_int_list(hex_str, k): ''' Aggregates bundles of k subsequent hex digits to one integer. Yields a list of ints.''' lst =  for i in range(0, len(hex_str), k): x = hex_str[i:i+k] x_int = int(x, base=16) lst.append(x_int) return np.array(lst) print(hex_to_int_list('01ffa87135affcd45deebe', 2)) # [ 1 255 168 113 53 175 252 212 93 238 190]
Let’s use two different values for
print(hex_to_int_list('01ffa87135affcd45deebe', 1)) # [ 0 1 15 15 10 8 7 1 3 5 10 15 15 12 13 4 5 13 14 14 11 14] print(hex_to_int_list('01ffa87135affcd45deebe', 4)) # [ 511 43121 13743 64724 24046 190]
Works too! 🙂
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