version.py

# PEP0440 compatible formatted version, see:
# https://www.python.org/dev/peps/pep-0440/
#
# Final Releases:
#   X(.Y)*
#   Ex: 0.9
#       0.9.1
#       0.9.2
# Pre-releases
#   X.YaN   # Alpha release
#   X.YbN   # Beta release
#   X.YrcN  # Release Candidate
#   X.Y.Z   # For bug-fix releases
#
# Post-releases:
#   X.YaN.postM   # Post-release of an alpha release
#   X.YbN.postM   # Post-release of a beta release
#   X.YrcN.postM  # Post-release of a release candidate
#
# Developmental releases
#   X.YaN.devM       # Developmental release of an alpha release
#   X.YbN.devM       # Developmental release of a beta release
#   X.YrcN.devM      # Developmental release of a release candidate
#   X.Y.postN.devM   # Developmental release of a post-release

import os

VERSION_FILE_NAME = "VERSION.txt"
VERSION_FILE_PATH = os.path.join(os.path.split(__file__)[0], VERSION_FILE_NAME)

# Read the VERSION.txt file and extract the version number
# Version number is saved in the following format
# (major, minor, patch, level, pre_identifier, dev_identifier, post_identifier)
try:
    with open(VERSION_FILE_PATH) as vf:
        _version = tuple(
            vf.read().strip().split(","))
        VERSION = (int(_version[0]), int(_version[1]), int(_version[2]), _version[3], int(
            _version[4]), int(_version[5]), int(_version[6]))
except IOError:
    raise RuntimeError(
        "Unable to read version file on path : {0}".format(VERSION_FILE_PATH))


def _construct_version(major, minor, patch, level, pre_identifier, dev_identifier, post_identifier):
    """Construct a PEP0440 compatible version number to be set to __version__"""
    assert level in ["alpha", "beta", "candidate", "final"]

    version = "{0}.{1}".format(major, minor)
    if patch:
        version += ".{0}".format(patch)

    if level == "final":
        if post_identifier:
            version += ".{0}{1}".format("post", post_identifier)
        if dev_identifier:
            version += ".{0}{1}".format("dev", dev_identifier)
    else:
        level_short = {"alpha": "a", "beta": "b", "candidate": "rc"}[level]
        version += "{0}{1}".format(level_short, pre_identifier)
        if post_identifier:
            version += ".{0}{1}".format("post", post_identifier)
        if dev_identifier:
            version += ".{0}{1}".format("dev", dev_identifier)
    return version


def construct_release_version(release_type, release_level="final"):
    """Constructs the version number based on the release type and level."""
    assert release_type in ["major", "minor", "patch", "premajor",
                            "preminor", "prepatch", "prenext", "dev", "post"]
    assert release_level in ["alpha", "beta", "candidate", "final"]

    # Extract the version sub parts from VERSION
    major, minor, patch, level, pre_identifier, dev_identifier, post_identifier = VERSION

    version = "{0}.{1}".format(major, minor)
    if release_type == "major":
        major += 1
        version = (major, 0, 0, release_level, 0, 0, 0)
    elif release_type == "minor":
        minor += 1
        version = (major, minor, 0, release_level, 0, 0, 0)
    elif release_type == "patch":
        patch += 1
        version = (major, minor, patch, release_level, 0, 0, 0)
    elif release_type == "premajor":
        major += 1
        version = (major, 0, 0, release_level, 1, 0, 0)
    elif release_type == "preminor":
        minor += 1
        version = (major, minor, 0, release_level, 1, 0, 0)
    elif release_type == "prepatch":
        patch += 1
        version = (major, minor, patch, release_level, 1, 0, 0)
    elif release_type == "prenext":
        pre_identifier += 1
        version = (major, minor, patch, release_level, pre_identifier, 0, 0)
    elif release_type == "dev":
        dev_identifier += 1
        version = (major, minor, patch, release_level,
                   pre_identifier, dev_identifier, post_identifier)
    elif release_type == "post":
        post_identifier += 1
        version = (major, minor, patch, release_level,
                   pre_identifier, dev_identifier, post_identifier)

    # Update the version file
    update_version_file(version)

    return _construct_version(*version)


def update_version_file(version):
    """Updates the version number in VERSION.txt file."""
    try:
        with open(VERSION_FILE_PATH, "w") as f:
            f.write(','.join(str(v) for v in version))
    except IOError:
        raise RuntimeError(
            "Unable to write to version file on path : {0}".format(VERSION_FILE_PATH))


__version__ = _construct_version(*VERSION)