1 # Copyright (C) 2010 Chris Jerdonek (cjerdonek@webkit.org)
3 # Redistribution and use in source and binary forms, with or without
4 # modification, are permitted provided that the following conditions
6 # 1. Redistributions of source code must retain the above copyright
7 # notice, this list of conditions and the following disclaimer.
8 # 2. Redistributions in binary form must reproduce the above copyright
9 # notice, this list of conditions and the following disclaimer in the
10 # documentation and/or other materials provided with the distribution.
12 # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
13 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
14 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
15 # DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR
16 # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
17 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
18 # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
19 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
20 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
21 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 """Supports Python version checking."""
29 _log = logging.getLogger(__name__)
32 # The minimum Python version the webkitpy package supports.
33 _MINIMUM_SUPPORTED_PYTHON_VERSION = "2.5"
36 def compare_version(sysmodule=None, target_version=None):
37 """Compare the current Python version with a target version.
40 sysmodule: An object with version and version_info data attributes
41 used to detect the current Python version. The attributes
42 should have the same semantics as sys.version and
43 sys.version_info. This parameter should only be used
44 for unit testing. Defaults to sys.
45 target_version: A string representing the Python version to compare
46 the current version against. The string should have
47 one of the following three forms: 2, 2.5, or 2.5.3.
48 Defaults to the minimum version that the webkitpy
52 A triple of (comparison, current_version, target_version).
54 comparison: An integer representing the result of comparing the
55 current version with the target version. A positive
56 number means the current version is greater than the
57 target, 0 means they are the same, and a negative number
58 means the current version is less than the target.
59 This method compares version information only up
60 to the precision of the given target version. For
61 example, if the target version is 2.6 and the current
62 version is 2.5.3, this method uses 2.5 for the purposes
63 of comparing with the target.
64 current_version: A string representing the current Python version, for
66 target_version: A string representing the version that the current
67 version was compared against, for example 2.5.
72 if target_version is None:
73 target_version = _MINIMUM_SUPPORTED_PYTHON_VERSION
75 # The number of version parts to compare.
76 precision = len(target_version.split("."))
78 # We use sys.version_info rather than sys.version since its first
79 # three elements are guaranteed to be integers.
80 current_version_info_to_compare = sysmodule.version_info[:precision]
81 # Convert integers to strings.
82 current_version_info_to_compare = map(str, current_version_info_to_compare)
83 current_version_to_compare = ".".join(current_version_info_to_compare)
85 # Compare version strings lexicographically.
86 if current_version_to_compare > target_version:
88 elif current_version_to_compare == target_version:
93 # The version number portion of the current version string, for
95 current_version = sysmodule.version.split()[0]
97 return (comparison, current_version, target_version)
100 # FIXME: Add a logging level parameter to allow the version message
101 # to be logged at levels other than WARNING, for example CRITICAL.
102 def check_version(log=None, sysmodule=None, target_version=None):
103 """Check the current Python version against a target version.
105 Logs a warning message if the current version is less than the
109 log: A logging.logger instance to use when logging the version warning.
110 Defaults to the logger of this module.
111 sysmodule: See the compare_version() docstring.
112 target_version: See the compare_version() docstring.
115 A boolean value of whether the current version is greater than
116 or equal to the target version.
122 (comparison, current_version, target_version) = \
123 compare_version(sysmodule, target_version)
126 # Then the current version is at least the minimum version.
129 message = ("WebKit Python scripts do not support your current Python "
130 "version (%s). The minimum supported version is %s.\n"
131 " See the following page to upgrade your Python version:\n\n"
132 " http://trac.webkit.org/wiki/PythonGuidelines\n"
133 % (current_version, target_version))