[Python-checkins] python/dist/src/Lib/distutils versionpredicate.py, NONE, 1.1

Sun Mar 20 23:17:04 CET 2005

Update of /cvsroot/python/python/dist/src/Lib/distutils
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv5161
Added Files:
	versionpredicate.py 
Log Message:
helper code, mostly from Andy Harrington, for PEP 314 completion
--- NEW FILE: versionpredicate.py ---
"""Module for parsing and testing package version predicate strings.
"""
import re
import version
import operator
re_validPackage = re.compile(r"(?i)^\s*([a-z_]\w*(?:\.[a-z_]\w*)*)(.*)")
# (package) (rest)
re_paren = re.compile(r"^\s*\((.*)\)\s*$") # (list) inside of parentheses
re_splitComparison = re.compile(r"^\s*(<=|>=|<|>|!=|==)\s*([^\s,]+)\s*$")
# (comp) (version)
def splitUp(pred):
 """Parse a single version comparison.
 Return (comparison string, StrictVersion)
 """
 res = re_splitComparison.match(pred)
 if not res:
 raise ValueError, "Bad package restriction syntax: " + pred
 comp, verStr = res.groups()
 return (comp, version.StrictVersion(verStr))
compmap = {"<": operator.lt, "<=": operator.le, "==": operator.eq,
 ">": operator.gt, ">=": operator.ge, "!=": operator.ne}
class VersionPredicate:
 """Parse and test package version predicates.
 >>> v = VersionPredicate("pyepat.abc (>1.0, <3333.3a1, !=1555.1b3)")
 >>> print v
 pyepat.abc (> 1.0, < 3333.3a1, != 1555.1b3)
 >>> v.satisfied_by("1.1")
 True
 >>> v.satisfied_by("1.4")
 True
 >>> v.satisfied_by("1.0")
 False
 >>> v.satisfied_by("4444.4")
 False
 >>> v.satisfied_by("1555.1b3")
 False
 >>> v = VersionPredicate("pat( == 0.1 ) ")
 >>> v.satisfied_by("0.1")
 True
 >>> v.satisfied_by("0.2")
 False
 >>> v = VersionPredicate("p1.p2.p3.p4(>=1.0, <=1.3a1, !=1.2zb3)")
 Traceback (most recent call last):
 ...
 ValueError: invalid version number '1.2zb3'
 """
 def __init__(self, versionPredicateStr):
 """Parse a version predicate string.
 """
 # Fields:
 # name: package name
 # pred: list of (comparison string, StrictVersion)
 versionPredicateStr = versionPredicateStr.strip()
 if not versionPredicateStr:
 raise ValueError, "Empty package restriction"
 match = re_validPackage.match(versionPredicateStr)
 if not match:
 raise ValueError, "Bad package name in " + versionPredicateStr
 self.name, paren = match.groups()
 paren = paren.strip()
 if paren:
 match = re_paren.match(paren)
 if not match:
 raise ValueError, "Expected parenthesized list: " + paren
 str = match.groups()[0]
 self.pred = [splitUp(aPred) for aPred in str.split(",")]
 if not self.pred:
 raise ValueError("Empty Parenthesized list in %r" 
 % versionPredicateStr )
 else:
 self.pred=[]
 def __str__(self):
 if self.pred:
 seq = [cond + " " + str(ver) for cond, ver in self.pred]
 return self.name + " (" + ", ".join(seq) + ")"
 else:
 return self.name
 def satisfied_by(self, version):
 """True if version is compatible with all the predicates in self.
 The parameter version must be acceptable to the StrictVersion
 constructor. It may be either a string or StrictVersion.
 """
 for cond, ver in self.pred:
 if not compmap[cond](version, ver):
 return False
 return True
def check_provision(value):
 m = re.match("[a-zA-Z_]\w*(\.[a-zA-Z_]\w*)*(\s*\([^)]+\))?$", value)
 if not m:
 raise ValueError("illegal provides specification: %r" % value)