Add patchVersion function that I will use for version management

fsl/version.py

@@ -5,7 +5,7 @@
 # Author: Paul McCarthy <pauldmccarthy@gmail.com>
 #
 """The primary purpose of this module is as a container for the ``fslpy``
-version number. A couple of conveniense functions for comparing version
+version number. A handful of convenience functions for managing version
 numbers are also defined here.
 
 .. autosummary::
@@ -14,10 +14,13 @@ numbers are also defined here.
    __version__
    parseVersionString
    compareVersions
+   patchVersion
 
 
 The ``fslpy`` version number consists of three numbers, separated by a period,
-which roughly obeys the Semantic Versioning conventions (http://semver.org/):
+roughly obeys the Semantic Versioning conventions (http://semver.org/), and
+is compatible with PEP 440 (https://www.python.org/dev/peps/pep-0440/):
+
 
  1. The major release number. This gets updated for major/external releases.
 
@@ -26,13 +29,19 @@ which roughly obeys the Semantic Versioning conventions (http://semver.org/):
 
  3. The point release number. This gets updated for minor/internal releases,
     which primarily involve bug-fixes and minor changes.
+
+
+The sole exception to the above convention are evelopment versions, which end
+in ``'.dev'``.
 """
 
 
-import string
+import os.path as op
+import            re
+import            string
 
 
-__version__ = 'dev'
+__version__ = '1.0.2.dev'
 """Current version number, as a string. """
 
 
@@ -44,21 +53,26 @@ def parseVersionString(versionString):
     An error is raised if the ``versionString`` is invalid.
     """
 
-    if versionString == 'dev':
-        return 9999, 9999, 9999
-
     components = versionString.split('.')
 
+    # Truncate after three elements -
+    # a development (unreleased0 version
+    # number will end with '.dev', but
+    # we ignore this for the purposes of
+    # comparison.
+    if len(components) == 4 and components[3] == 'dev':
+        components = components[:3]
+
     # Major, minor, and point
     # version are always numeric
     major, minor, point = [c for c in components]
 
-    # Early versions of FSLeyes
+    # But early versions of FSLeyes
     # used a letter at the end
     # to denote a hotfix release.
     # Don't break if we get one
     # of these old version numbers.
-    point = point.strip(string.ascii_letters)
+    point = point.rstrip(string.ascii_letters)
 
     return [int(c) for c in [major, minor, point]]
 
@@ -91,3 +105,27 @@ def compareVersions(v1, v2, ignorePoint=False):
         if p1 < p2: return -1
 
     return 0
+
+
+def patchVersion(filename, newversion):
+    """Patches the given ``filename``, in place, with the given
+    ``newversion``. Searches for a line of the form::
+
+        __version__ = '<oldversion>'
+
+    and replaces ``<oldversion>`` with ``newversion``.
+    """
+    filename = op.abspath(filename)
+
+    with open(filename, 'rt') as f:
+        lines = f.readlines()
+
+    pattern = re.compile('^__version__ *= *\'.*\' *$')
+
+    for i, line in enumerate(lines):
+        if pattern.match(line):
+            lines[i] = '__version__ = \'{0}\'\n'.format(newversion)
+            break
+
+    with open(filename, 'wt') as f:
+        lines = f.writelines(lines)