parse_ranges: nouvelle solution

parse_ranges/parse_ranges.py

@@ -54,4 +54,42 @@ def parse_ranges_v4(range_string):
                 yield number
 
 
-parse_ranges = parse_ranges_v4
+def parse_ranges_v5(range_string):
+    """Revisiting the solution after reading Trey's answer.
+    
+    The part 'for (begin, _, end) in [subrange.partition("-")]' is tricky as it is here
+    to 'iterate' over the one element list and thus assign the 3-tuple we need inside
+    the comprehension.
+
+    Comprehesion are a way to write for loops and the one we want to write is:
+        ranges = []
+        for subrange in range_string.split(","):
+            begin, _, end = subrange.partition("-")
+            if end.isdecimal():
+                ranges.append(start, end)
+            else:
+                ranges.append(start, start)
+
+    Read more here: https://nedbatchelder.com/blog/201802/a_python_gargoyle.html
+    """
+    range_string = range_string.replace("->", "-")
+
+    return (
+        number
+        for start, stop in (
+            (begin, end) if end.isdecimal() else (begin, begin)
+            for subrange in range_string.split(",")
+            for (begin, _, end) in [subrange.partition("-")]
+        )
+        for number in range(int(start), int(stop) + 1)
+    )
+
+
+# L'idée principale de la correction est l'expression de générateur :
+# (EXPRESSION for NOM in ITERABLE) qui permet de rester 'fainéant' de bout en bout !
+#
+# Et bien sûr la gargouille for (begin, _, end) in [subrange.partition("-")]
+# à utiliser avec modération car la lisibilité compte !
+
+
+parse_ranges = parse_ranges_v5