Changes between Version 73 and Version 74 of DeveloperGuidelines/Py_2_3

Timestamp:

07/10/19 22:14:23 (6 years ago)

Author:

Dominic König

Comment:

--

DeveloperGuidelines/Py_2_3

@@ -300 +300 @@
 
 - {{{zipfile}}} expects and returns {{{bytes}}}
+
+=== Sorting requires type consistency ===
+
+When sorting iterables with {{{i.sort()}}} or {{{sorted(i)}}}, all elements must have the same type - otherwise it will raise a {{{TypeError}}} in Python-3.
+
+This is particularly relevant when the iterable can contain {{{None}}}. In such a case, use a key function to deal with None:
+{{{#!python
+l = [4,2,7,None]
+
+# Works in Py2, but raises a TypeError in Py3:
+l.sort()
+
+# Works in both:
+l.sort(key=lambda item: item if item is not None else -float('inf'))
+}}}