"""An Atom."""
[docs]class AtomException(Exception):
"""An exception in this class."""
pass
[docs]class Atom(object):
def __init__(self, atom):
# We expect an atom of the form [=]CATEGORY/PACKAGE[-VERSION].
self.category = None
self.package = None
self.version = None
# We don't store the optional '='.
temp = atom.split("=")
self.atom = temp[-1]
try:
self.category, self.package = self.atom.split("/")
except ValueError:
raise AtomException(
"ATOM has to be of the form [=]SECTION/PACKAGE[-VERSION]")
# Split off version.
try:
temp = self.package.index("-")
if temp > -1:
self.version = self.package[temp + 1:]
self.package = self.package[:temp]
except ValueError:
pass
def __str__(self):
if self.version is not None:
prefix = "="
suffix = "-" + self.version
else:
prefix = ""
suffix = ""
return prefix + self.category + "/" + self.package + suffix
def __eq__(self, other):
result = (self.atom == other.atom)
return result
def __repr__(self):
return "Atom(\"%s\")" % self.__str__()