code refactor

related to #8 (closed):

• I kept changes per commit small, so the number of commits got kind of numerous...

src/icartt/dataset.py

@@ -362,8 +362,8 @@ class Variable:
         self.miss = miss
 
     def __repr__(self):
-        # TODO: this sould be more meaningful
-        return "ICARTT Variable object repr"
+        # TODO: this sould be something else than __str__ ?
+        return self.desc()
 
     def __str__(self):
         return self.desc()
@@ -419,9 +419,10 @@ class Dataset:
         :return: list of time steps
         :rtype: list
         """
+        # TODO: this method currently does not work at all.
+        #       suggest to also change to return a numpy array of numpy.datetime64
+        #       for consistency with other data output
         return [
-            # TODO see commit f5208db0 - this will do unexpected things if
-            #      self.dateOfCollection is a naive datetime object (think DST transitions...)
             self.dateOfCollection + datetime.timedelta(seconds=x)
             for x in self.independentVariable
         ]
@@ -507,8 +508,11 @@ class Dataset:
         # line 7 - UTC date when data begin, UTC date of data reduction or revision
         # - comma delimited (yyyy, mm, dd, yyyy, mm, dd).
         dmp = f.readline()
-        self.dateOfCollection = datetime.datetime(*map(int, dmp[:3])) # TODO: set UTC ?!
+        self.dateOfCollection = datetime.datetime(*map(int, dmp[:3]))
         self.dateOfRevision = datetime.datetime(*map(int, dmp[3:6]))
+        # TODO: we should either use aware datetime (UTC), date objects or
+        #       numpy.datetime64 here to avoid some 'rough edges' of Python's datetime library...
+
 
         # line 8 - Data Interval (This value describes the time spacing (in seconds)
         # between consecutive data records. It is the (constant) interval between
@@ -865,7 +869,8 @@ class Dataset:
         # TODO: this could be more meaningful
         return "ICARTT Dataset string representation"
 
-    def __init__(self, f=None, loadData=True, splitChar=",", format=Formats.FFI1001): # TODO: why is init comming last?
+    # TODO: why is init comming last?
+    def __init__(self, f=None, loadData=True, splitChar=",", format=Formats.FFI1001):
         """Constructor method"""
         self.format = format
         self.version = None
@@ -883,8 +888,10 @@ class Dataset:
         self.dataSourceDescription = "Musterdatenprodukt"
         self.missionName = "MUSTEREX"
 
-        # TODO: not 100%  sure if this is relevant here, but those dates should refer to UTC
-        # - if you leave the datetime objects naive (no tzinfo set), they represent local time.
+        # TODO: see also comment on _readData method.
+        #       we should either use aware datetime (UTC), date objects or
+        #       numpy.datetime64 here to avoid some 'rough edges' of Python's
+        #       datetime library...
         self.dateOfCollection = datetime.datetime.today()
         self.dateOfRevision = datetime.datetime.today()
         self.dataIntervalCode = [0.0]