diff --git a/src/icartt/dataset.py b/src/icartt/dataset.py
index 1528158734013c22172b05a39313f1faaddb41f6..d49ceaf7d7379a577edba30d88f905b60ab44714 100644
--- a/src/icartt/dataset.py
+++ b/src/icartt/dataset.py
@@ -352,9 +352,9 @@ class Variable:
         # The first character must be a letter,
         firstIsAlpha = bool(re.match("[a-zA-Z]", name[0]))
         # and the name can be at most 31 characters in length.
-        lessThan31Chars = len(name) <= 31
+        le31Chars = len(name) <= 31
 
-        return allAreAlphaOrUnderscore and firstIsAlpha and lessThan31Chars
+        return allAreAlphaOrUnderscore and firstIsAlpha and le31Chars
 
     def __init__(
         self,
@@ -401,6 +401,9 @@ class Variable:
         self.scale = scale
         self.miss = miss
 
+    def __repr__(self):
+        return f"[{self.units}], {self.vartype.name}"
+
     def __str__(self):
         return self.desc()
 
@@ -448,7 +451,7 @@ class Dataset:
         if self.defineMode:
             return np.datetime64("NaT")
 
-        # for 1001, its an array, for 2110 a dict
+        # for 1001 it's an array, for 2110 a dict
         if not isinstance(self.data.data, (np.ndarray, dict)):
             return np.datetime64("NaT")
 
@@ -1011,8 +1014,10 @@ class Dataset:
 
             if not self.isValidFileName(pathlib.Path(f).name):
                 warnings.warn(f"{pathlib.Path(f).name} is not a valid ICARTT filename")
-            else:  # try to obtain dataID and locationID from file name
+            else:
+                # try to obtain dataID and locationID from file name
                 parts = pathlib.Path(f).name.split("_")
+                # there should be at least 3 parts; data ID, location ID and revision date + file name extension
                 if len(parts) > 2:
                     self.dataID = parts[0]
                     self.locationID = parts[1]