avoid .split() in for loops and use tuples instead

split can be more readable for longer lists like the list in
dirstate.invalidate. As dirstate.invalidate is used in wlock() and therefoe
used heavily, I think it's worth avoiding a split there too.

mercurial/dirstate.py

@@ -230,7 +230,8 b' class dirstate(object):'
             self._pl = p
 
     def invalidate(self):
-        for a in "_map _copymap _foldmap _branch _pl _dirs _ignore".split():
+        for a in ("_map", "_copymap", "_foldmap", "_branch", "_pl", "_dirs",
+                "_ignore"):
             if a in self.__dict__:
                 delattr(self, a)
         self._dirty = False

mercurial/localrepo.py

@@ -733,7 +733,7 b' class localrepository(repo.repository):'
         self._branchcachetip = None
 
     def invalidate(self):
-        for a in "changelog manifest".split():
+        for a in ("changelog", "manifest"):
             if a in self.__dict__:
                 delattr(self, a)
         self.invalidatecaches()

mercurial/util.py

@@ -1099,7 +1099,7 b' def parsedate(date, formats=None, defaul'
         if not defaults:
             defaults = {}
         now = makedate()
-        for part in "d mb yY HI M S".split():
+        for part in ("d", "mb", "yY", "HI", "M", "S"):
             if part not in defaults:
                 if part[0] in "HMS":
                     defaults[part] = "00"
@@ -1146,7 +1146,7 b' def matchdate(date):'
 
     def upper(date):
         d = dict(mb="12", HI="23", M="59", S="59")
-        for days in "31 30 29".split():
+        for days in ("31", "30", "29"):
             try:
                 d["d"] = days
                 return parsedate(date, extendeddateformats, d)[0]