enable npm and maven prerelease version syntax

semver/utils.py

@@ -0,0 +1,41 @@
+import subprocess
+from semver.logger import logging, logger, console_logger
+
+try:
+    from configparser import ConfigParser
+except ImportError:
+    # Python < 3
+    from ConfigParser import ConfigParser
+
+try:
+    from subprocess import DEVNULL # py3k
+except ImportError:
+    import os
+    DEVNULL = open(os.devnull, 'wb')
+
+def get_tag_version():
+    config = ConfigParser()
+    config.read('./.bumpversion.cfg')
+    tag_expression = config.get('bumpversion','tag_name').replace('{new_version}','[0-9]*.[0-9]*.[0-9]*')
+
+    logger.debug("Tag expression: " + str(tag_expression))
+
+    # Default version is `0.0.0` or what is found in 
+    version = get_file_version(config)
+
+    # If a version is found in tags, use that the lastest tagged version
+    tagged_versions = subprocess.Popen(['git','tag','--sort=v:refname', '-l',tag_expression],
+        stdout=subprocess.PIPE, stderr=DEVNULL, cwd=".").stdout.read().decode('utf-8').rstrip().split('\n')
+    if len(tagged_versions) > 0 and tagged_versions[-1] != "":
+        version = tagged_versions[-1]
+
+    logger.debug("Tag Version: " + str(version))
+    return version
+
+def get_file_version(config):
+    version = config.get('bumpversion','current_version')
+    if not version:
+        config.set('bumpversion', 'current_version', '0.0.0')
+        version = '0.0.0'
+    return version
+