#! /usr/bin/env python

import datetime
import os
import subprocess


def get_git_hash(hash_format="H"):
    """
    Returns an alphanumeric identifier of the latest git hash.
    """
    repo_dir = os.path.dirname(os.path.abspath(__file__))
    git_log = subprocess.Popen(
        'git log --pretty=format:%{} --quiet -1 HEAD'.format(hash_format),
        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
        shell=True, cwd=repo_dir, universal_newlines=True)
    git_hash = git_log.communicate()[0]

    if not git_hash:
        git_hash = 'unknown'

    return git_hash


def get_git_hash_short():
    """
    Returns an alphanumeric identifier of the latest git hash.
    """
    return get_git_hash("h")


def get_git_changeset():
    """Returns a numeric identifier of the latest git changeset.

    The result is the UTC timestamp of the changeset in YYYYMMDDHHMMSS format.
    This value isn't guaranteed to be unique, but collisions are very unlikely,
    so it's sufficient for generating the development version numbers.
    """
    repo_dir = os.path.dirname(os.path.abspath(__file__))
    git_log = subprocess.Popen(
        'git log --pretty=format:%ct --quiet -1 HEAD',
        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
        shell=True, cwd=repo_dir, universal_newlines=True)
    timestamp = git_log.communicate()[0]
    try:
        timestamp = datetime.datetime.utcfromtimestamp(int(timestamp))
    except ValueError:
        return None
    return timestamp.strftime('%Y%m%d%H%M%S')

#! /usr/bin/env python

import datetime
import os
import subprocess


def get_version(version):
    """
    Returns a PEP 386-compliant version number from VERSION

    Given a 5 tuple of (X, Y, Z, rel, N) return a PEP-386 compliant version
    string
    """
    assert len(version) == 5
    assert version[3] in ('alpha', 'beta', 'rc', 'final')

    # Now build the two parts of the version number:
    # main = X.Y[.Z]
    # sub = .devN - for pre-alpha releases
    #     | {a|b|c}N - for alpha, beta and rc releases

    parts = 2 if version[2] == 0 else 3
    main = '.'.join(str(x) for x in version[:parts])

    sub = ''
    if version[3] == 'alpha' and version[4] == 0:
        git_changeset = get_git_changeset()
        if git_changeset:
            sub = '.dev%s' % git_changeset

    elif version[3] != 'final':
        mapping = {'alpha': 'a', 'beta': 'b', 'rc': 'c'}
        sub = mapping[version[3]] + str(version[4])

    return str(main + sub)


def get_git_hash(hash_format="H"):
    """
    Returns an alphanumeric identifier of the latest git hash.
    """
    repo_dir = os.path.dirname(os.path.abspath(__file__))
    git_log = subprocess.Popen(
        'git log --pretty=format:%{} --quiet -1 HEAD'.format(hash_format),
        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
        shell=True, cwd=repo_dir, universal_newlines=True)
    git_hash = git_log.communicate()[0]

    if not git_hash:
        git_hash = 'unknown'

    return git_hash


def get_git_hash_short():
    """
    Returns an alphanumeric identifier of the latest git hash.
    """
    return get_git_hash("h")


def get_git_changeset():
    """Returns a numeric identifier of the latest git changeset.

    The result is the UTC timestamp of the changeset in YYYYMMDDHHMMSS format.
    This value isn't guaranteed to be unique, but collisions are very unlikely,
    so it's sufficient for generating the development version numbers.
    """
    repo_dir = os.path.dirname(os.path.abspath(__file__))
    git_log = subprocess.Popen(
        'git log --pretty=format:%ct --quiet -1 HEAD',
        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
        shell=True, cwd=repo_dir, universal_newlines=True)
    timestamp = git_log.communicate()[0]
    try:
        timestamp = datetime.datetime.utcfromtimestamp(int(timestamp))
    except ValueError:
        return None
    return timestamp.strftime('%Y%m%d%H%M%S')

Add function to turn a 5-tuple into a PEP-386 compliant version string