JezK
Edit File: versionpredicate.py
"""Module for parsing and testing package version predicate strings. """ import re import distutils.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: %r" % pred) comp, verStr = res.groups() return (comp, distutils.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)') The `name` attribute provides the full dotted name that is given:: >>> v.name 'pyepat.abc' The str() of a `VersionPredicate` provides a normalized human-readable version of the expression:: >>> print v pyepat.abc (> 1.0, < 3333.3a1, != 1555.1b3) The `satisfied_by()` method can be used to determine with a given version number is included in the set described by the version restrictions:: >>> 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 `VersionPredicate` is flexible in accepting extra whitespace:: >>> v = VersionPredicate(' pat( == 0.1 ) ') >>> v.name 'pat' >>> v.satisfied_by('0.1') True >>> v.satisfied_by('0.2') False If any version numbers passed in do not conform to the restrictions of `StrictVersion`, a `ValueError` is raised:: >>> v = VersionPredicate('p1.p2.p3.p4(>=1.0, <=1.3a1, !=1.2zb3)') Traceback (most recent call last): ... ValueError: invalid version number '1.2zb3' It the module or package name given does not conform to what's allowed as a legal module or package name, `ValueError` is raised:: >>> v = VersionPredicate('foo-bar') Traceback (most recent call last): ... ValueError: expected parenthesized list: '-bar' >>> v = VersionPredicate('foo bar (12.21)') Traceback (most recent call last): ... ValueError: expected parenthesized list: 'bar (12.21)' """ 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 %r" % versionPredicateStr) self.name, paren = match.groups() paren = paren.strip() if paren: match = re_paren.match(paren) if not match: raise ValueError("expected parenthesized list: %r" % 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 _provision_rx = None def split_provision(value): """Return the name and optional version number of a provision. The version number, if given, will be returned as a `StrictVersion` instance, otherwise it will be `None`. >>> split_provision('mypkg') ('mypkg', None) >>> split_provision(' mypkg( 1.2 ) ') ('mypkg', StrictVersion ('1.2')) """ global _provision_rx if _provision_rx is None: _provision_rx = re.compile( "([a-zA-Z_]\w*(?:\.[a-zA-Z_]\w*)*)(?:\s*\(\s*([^)\s]+)\s*\))?$") value = value.strip() m = _provision_rx.match(value) if not m: raise ValueError("illegal provides specification: %r" % value) ver = m.group(2) or None if ver: ver = distutils.version.StrictVersion(ver) return m.group(1), ver