avoid mutable defaults like [], {} in method declarations

common/python/nomadcore/simple_parser.py

@@ -27,7 +27,7 @@ annotate = False
 class PushbackLineFile(object):
     """a file interface where it is possible to put back read lines"""
 
-    def __init__(self, fIn, lines = []):
+    def __init__(self, fIn, lines=tuple()):
         self.fIn = fIn
         self.lines = list(lines)
         self.lineNr = 0
@@ -57,7 +57,7 @@ class SimpleMatcher(object):
         # if the matcher has weak == true, this matcher should nevel steal
         # the matcher can/should repeat immediately
 
-    def __init__(self, startReStr, endReStr = None, subMatchers = [], sections = [],
+    def __init__(self, startReStr, endReStr = None, subMatchers = tuple(), sections = tuple(),
                  subFlags = SubFlags.Sequenced,
                  weak = False,     # this matcher should not "steal" the position
                  repeats = False,  # this matcher is expected to repeat
@@ -67,10 +67,10 @@ class SimpleMatcher(object):
                  forwardMatch = False, # if start match should not eat input, but be forwarded to adHoc and subMatchers
                  name = "",
                  adHoc = None,
-                 otherMetaInfo = [], # The metainfos that are later manually added ot the backend
+                 otherMetaInfo = tuple(), # The metainfos that are later manually added ot the backend
                  fixedStartValues = None,
                  fixedEndValues = None,
-                 dependencies={},
+                 dependencies = None,
                  defLine=0,
                  defFile='',
                  coverageIgnore=False, # mark line as ignored in coverage analysis
@@ -82,8 +82,8 @@ class SimpleMatcher(object):
         self.index = -1
         self.startReStr = startReStr
         self.endReStr = endReStr
-        self.subMatchers = subMatchers
-        self.sections = sections
+        self.subMatchers = list(subMatchers)
+        self.sections = list(sections)
         self.subFlags = subFlags
         self.weak = weak
         self.repeats = repeats
@@ -92,7 +92,9 @@ class SimpleMatcher(object):
         self.forwardMatch = forwardMatch
         self.superMatcher = None
         self.adHoc = adHoc
-        self.otherMetaInfo = otherMetaInfo
+        self.otherMetaInfo = list(otherMetaInfo)
+        if dependencies is None:
+            dependencies = {}
         self.dependencies = dependencies
         self.name = name
         self.fixedStartValues = fixedStartValues
@@ -239,9 +241,12 @@ class SimpleMatcher(object):
             groups.extend(extractGroupNames(self.endReStr))
         return groups
 
-    def allMetaNames(self, metaNames=[]):
+    def allMetaNames(self, metaNames=None):
         """The names of the meta infos the could be matched by this matcher or its sub matchers.
         groups can be a """
+        if metaNames is None:
+            metaNames = []
+
         metaNames.extend(self.directMetaNames())
         for m in self.subMatchers:
             m.allMetaNames(metaNames)
@@ -1281,20 +1286,20 @@ def defaultParseFile(parserInfo):
 def mainFunction(mainFileDescription,
                  metaInfoEnv,
                  parserInfo,
-                 parseFile = None,
-                 outF = sys.stdout,
-                 cachingLevelForMetaName = {},
-                 defaultDataCachingLevel = CachingLevel.ForwardAndCache,
-                 defaultSectionCachingLevel = CachingLevel.Forward,
-                 superContext = None,
-                 onClose = {},
-                 onOpen = {},
+                 parseFile=None,
+                 outF=sys.stdout,
+                 cachingLevelForMetaName=None,
+                 defaultDataCachingLevel=CachingLevel.ForwardAndCache,
+                 defaultSectionCachingLevel=CachingLevel.Forward,
+                 superContext=None,
+                 onClose=None,
+                 onOpen=None,
                  default_units=None,
                  metainfo_units=None,
                  superBackend=None,
                  metaInfoToKeep=None,
                  mainFile=None,
-                 strValueTransform={}):
+                 strValueTransform=None):
     """
     Args:
         default_units: A list of default unit definitions.
@@ -1330,6 +1335,16 @@ def mainFunction(mainFileDescription,
     verbose = False
     fileToParse = None
     writeMatchTelemetry = False
+
+    if cachingLevelForMetaName is None:
+        cachingLevelForMetaName = {}
+    if onClose is None:
+        onClose = {}
+    if onOpen is None:
+        onOpen = {}
+    if strValueTransform is None:
+        strValueTransform = {}
+
     ii = 1
     while ii < len(sys.argv):
         arg = sys.argv[ii]
@@ -1531,7 +1546,7 @@ class ParserOptimizer(object):
     """For optimizing a hierarchy of SimpleMatchers based on a list of metainfo
     names that should be included in the parsing.
     """
-    def optimizeParsingTree(self, rootMatcher, metaInfoToKeep=[]):
+    def optimizeParsingTree(self, rootMatcher, metaInfoToKeep=None):
         """This function will remove any parsing unnecessary parsing actions
         from the parsing tree based on the given list of metainfo names to keep
         and metainfo names to skip.
@@ -1542,6 +1557,9 @@ class ParserOptimizer(object):
             metaInfoToKeep: List of metainfonames to keep in parsing
         """
         # First identify the parts that should be kept
+        if metaInfoToKeep is None:
+            metaInfoToKeep = []
+
         if metaInfoToKeep:
 
             # Single values are put inside a list for convenience