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long(), print(), xrange() for Python 3

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Also remove trailing whitespace
This commit is contained in:
cclauss 2017-08-24 18:37:02 +02:00 committed by GitHub
parent 3c0b24edd7
commit 35fef9a94f
1 changed files with 35 additions and 34 deletions
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69
code/proof-of-work-example.py
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@ -4,60 +4,61 @@
import hashlib
import time
max_nonce = 2 ** 32 # 4 billion
try:
long # Python 2
xrange
except NameError:
long = int # Python 3
xrange = range
max_nonce = 2 ** 32 # 4 billion
def proof_of_work(header, difficulty_bits):
# calculate the difficulty target
target = 2 ** (256-difficulty_bits)
target = 2 ** (256 - difficulty_bits)
for nonce in xrange(max_nonce):
hash_result = hashlib.sha256(str(header)+str(nonce)).hexdigest()
hash_result = hashlib.sha256(str(header) + str(nonce)).hexdigest()
# check if this is a valid result, below the target
if long(hash_result, 16) < target:
print "Success with nonce %d" % nonce
print "Hash is %s" % hash_result
return (hash_result,nonce)
print "Failed after %d (max_nonce) tries" % nonce
print("Success with nonce %d" % nonce)
print("Hash is %s" % hash_result)
return (hash_result, nonce)
print("Failed after %d (max_nonce) tries" % nonce)
return nonce
if __name__ == '__main__':
nonce = 0
hash_result = ''
# difficulty from 0 to 31 bits
# difficulty from 0 to 31 bits
for difficulty_bits in xrange(32):
difficulty = 2 ** difficulty_bits
print "Difficulty: %ld (%d bits)" % (difficulty, difficulty_bits)
print "Starting search..."
print("Difficulty: %ld (%d bits)" % (difficulty, difficulty_bits))
print("Starting search...")
# checkpoint the current time
start_time = time.time()
# make a new block which includes the hash from the previous block
# we fake a block of transactions - just a string
new_block = 'test block with transactions' + hash_result
new_block = 'test block with transactions' + hash_result
# find a valid nonce for the new block
(hash_result, nonce) = proof_of_work(new_block, difficulty_bits)
(hash_result, nonce) = proof_of_work(new_block, difficulty_bits)
# checkpoint how long it took to find a result
end_time = time.time()
elapsed_time = end_time - start_time
print "Elapsed Time: %.4f seconds" % elapsed_time
print("Elapsed Time: %.4f seconds" % elapsed_time)
if elapsed_time > 0:
# estimate the hashes per second
hash_power = float(long(nonce)/elapsed_time)
print "Hashing Power: %ld hashes per second" % hash_power
hash_power = float(long(nonce) / elapsed_time)
print("Hashing Power: %ld hashes per second" % hash_power)