Changes between Version 24 and Version 25 of DeveloperGuidelines/Py_2_3

Timestamp:

06/28/19 08:24:43 (6 years ago)

Author:

Dominic König

Comment:

--

DeveloperGuidelines/Py_2_3

@@ -128 +128 @@
 
 The same applies to {{{dict.iterkeys()}}} (use {{{dict.keys()}}} instead) and {{{dict.itervalues()}}} (use {{{dict.values()}}} instead).
+
+=== Map and Zip return generators ===
+
+In Python-3, the {{{map()}}} and {{{zip()}}} functions return generator objects rather than lists. Where lists are required, the return value must be converted explicitly using the list constructor. Where possible, we prefer list comprehensions.
+{{{
+# This is fine:
+for item in map(func, values):
+# This could be wrong:
+result = map(func, values)
+# This is better:
+result = list(map(func, values))
+# This could be even better (though not for multiple iterables):
+result = [func(v) for v in values]
+}}}