python3 sha256 pure code example

Example 1: python sha256 of file

# Python program to find SHA256 hash string of a file
import hashlib
 
filename = input("Enter the input file name: ")
sha256_hash = hashlib.sha256()
with open(filename,"rb") as f:
    # Read and update hash string value in blocks of 4K
    for byte_block in iter(lambda: f.read(4096),b""):
        sha256_hash.update(byte_block)
    print(sha256_hash.hexdigest())

Example 2: python hmac sha256

# python 2
import hmac
import hashlib

nonce = 1234
customer_id = 123232
api_key = 2342342348273482374343434
API_SECRET = 892374928347928347283473

message = '{} {} {}'.format(nonce, customer_id, api_key)
signature = hmac.new(
    str(API_SECRET),
    msg=message,
    digestmod=hashlib.sha256
).hexdigest().upper()

print signature