PyC4 - Python C4

Python module for the Cinema Content Creation Cloud frame work.

Python Classes

C4

The pyc4.C4 class can be used to generate c4 id hashes of file names. All operations are done in the main thread.

>>> import pyc4
>>> c4 = pyc4.C4()
>>> c4id = c4.from_file('tests/conftest.py')
>>> str(c4id)
'c42M9bHvXEt7dX78AvxXVwA9FzadXeNGYyLEiDV4UJMbjsi3VoMLLooWwog88VegG4W4R6m1d5Mj6UozNqk2HkKZyd'
>>> c4id.format()
'c42M9bHvXEt7dX78AvxXVwA9FzadXeNGYyLEiDV4UJMbjsi3VoMLLooWwog88VegG4W4R6m1d5Mj6UozNqk2HkKZyd'
>>> print(c4id.format(show_metadata=True, absolute=True))
c42M9bHvXEt7dX78AvxXVwA9FzadXeNGYyLEiDV4UJMbjsi3VoMLLooWwog88VegG4W4R6m1d5Mj6UozNqk2HkKZyd:
  path: "tests/conftest.py"
  name:  "conftest.py"
  folder:  false
  link:  false
  bytes:  1263

If you want to report progress you can store a callback function on the c4 instance. The progress callback takes a single argument that is a int from 0 to 100 that represents the percentage of the file hash completed. If the file is smaller than c4.block_size, this function may not be called. The command line interface uses the C4.progress_default function.

>>> c4 = pyc4.C4()
>>> c4.block_size = 1000 # Set a custom block size so we can see progress on a small file
>>> def progress_report(percent):
...     print('Hash progress: {}'.format(percent))
...
>>> c4.progress_callback = progress_report
>>> c4id = c4.from_file('tests/test_c4.py')
Hash progress: 25
Hash progress: 50
Hash progress: 75
Hash progress: 100

C4Queue

The pyc4.C4Queue class can be used to generate c4 id hashes in multiple threads using python's threading and queue system.

>>> import pyc4
>>> import glob
>>> c4 = pyc4.C4Queue()
>>> c4.max_threads = 10 # limit the number of threads used to process
>>> c4.files = glob.glob('tests/*.*')
>>> c4.files
['tests/test_c4queue.py', 'tests/README.md', 'tests/test_c4.py', 'tests/conftest.py']
>>> c4.start() # start processing c4.files
>>> c4.join() # wait for all files to be processed
>>> for c4id in c4.hashes.values(): # view the results
...     print(c4id.format(show_path=True))
...
c45eU7ER3yEH8XTQARpvqXmis7xACMDGxc5Js57adRdkgqWzBPrUHW5Lr3duA7eZfQAHn8zbX7uiqGuTAfnVKExg3w:
  path: "tests/test_c4queue.py"
c41SEWLV2BU5thHvo68gkiYKxkxNgpJ9gjboeWyYbMNmNcabEZEpT3FXSbqiVG3SidzSZxT83nnSyihfe6SduS3m8b:
  path: "tests/README.md"
c43Nw48VmxSF8w9Nzxz3CffVPVVrKkiA8qPqexboMGq5EDncxHXiayPTX2zHo6cxJY2mqnCxAw7tRuQn2pDMEe1omv:
  path: "tests/test_c4.py"
c4627mr9eneAJSgEEDPQgTYa8Qecu5mp6To649fj1CBUyGEmzpEr7HGRghnqrJmR7FUv8f1o9ieX5qR7BR1WAcknzh:
  path: "tests/conftest.py"

C4Queue.join may call C4Queue.progress_callback if there are more files than max_threads. The percent represents the total number of items processed, not how much of a individual file has been processed.

When using C4Queue, you can store a callback function on the C4Queue.worker_finished_callback method. This will be called every time a worker thread finishes processing a file in its queue. The worker finished callback should take a C4id object.

>>> import pyc4
>>> import glob
>>> def hash_finished(c4id):
...     print(c4id.format(show_path=True))
...
>>> c4 = pyc4.C4Queue()
>>> c4.worker_finished_callback = hash_finished
>>> c4.files = glob.glob('tests/*.*')
>>> c4.start()
c45eU7ER3yEH8XTQARpvqXmis7xACMDGxc5Js57adRdkgqWzBPrUHW5Lr3duA7eZfQAHn8zbX7uiqGuTAfnVKExg3w:
  path: "tests/test_c4queue.py"
c41SEWLV2BU5thHvo68gkiYKxkxNgpJ9gjboeWyYbMNmNcabEZEpT3FXSbqiVG3SidzSZxT83nnSyihfe6SduS3m8b:
  path: "tests/README.md"
c43Nw48VmxSF8w9Nzxz3CffVPVVrKkiA8qPqexboMGq5EDncxHXiayPTX2zHo6cxJY2mqnCxAw7tRuQn2pDMEe1omv:
  path: "tests/test_c4.py"
c4627mr9eneAJSgEEDPQgTYa8Qecu5mp6To649fj1CBUyGEmzpEr7HGRghnqrJmR7FUv8f1o9ieX5qR7BR1WAcknzh:
  path: "tests/conftest.py"

C4id

This class contains the metadata for a given c4 id and file. It contains the file path and c4id string, and can be used to generate c4 id metadata strings.

Command line use

The main pyc4.py file can be used to generate c4 hashes from the command line.

$ python /usr/lib/python2.7/site-packages/pyc4.py tests
c454KKaE2vUn4PqkwthZwcWBqgySyGWBKbZ74k1JRJM59spUbGU6bTRMEbP2hsUuA1u11ipYBfUodNtWxQEGp53CwW
c44762SPbNNtwpa9GmTcGf5tFj1de9xbU52Ai25eQNNRT85D9J9XkLuKCS2DsT4fuMBop97jCfsV7QKd7tPxLGsKTQ
...

 $ python /usr/lib/python2.7/site-packages/pyc4.py tests/conftest.py -m
c42M9bHvXEt7dX78AvxXVwA9FzadXeNGYyLEiDV4UJMbjsi3VoMLLooWwog88VegG4W4R6m1d5Mj6UozNqk2HkKZyd:
  path: "tests/conftest.py"
  name:  "conftest.py"
  folder:  false
  link:  false
  bytes:  1263

However, if you are using the command line, a better option would be c4 cli written in go.