Changes between Version 46 and Version 47 of DeveloperGuidelines/Py_2_3

Timestamp:

07/04/19 19:55:12 (6 years ago)

Author:

Dominic König

Comment:

--

DeveloperGuidelines/Py_2_3

@@ -199 +199 @@
 === Don't unicode.encode ===
 
-Since there is no difference between {{{unicode}}} and {{{str}}}, using the {{{encode()}}} method will produce {{{bytes}}} rather than {{{str}}}.
-
-{{{bytes}}} differs from string in that it is an array of integers rather than an array of characters. It will also give a distorted result with any later {{{str()}}} or {{{s3_str()}}}.
-
-If you just want to encode a potential {{{unicode}}} instance as an utf-8 encoded {{{str}}}, use {{{s3_str}}} rather than {{{unicode.encode}}}.
+Since there is no difference between {{{unicode}}} and {{{str}}}, using the {{{encode()}}} method will produce {{{bytes}}} rather than {{{str}}}. A {{{bytes}}} object differs from string in that it is an array of integers rather than an array of characters. It will also give a distorted result with any later {{{str()}}} or {{{s3_str()}}}.
+
+{{{#!python
+if isinstance(x, unicodeT):  # unicodeT maps to str in Py3
+    x = x.encode("utf-8")    # x becomes a bytes-object in Py3, unlike in Py2 where it becomes a str
+
+str(x)                       # thus, in Py3, this results in something like "b'example'" instead of the expected "example"
+
+x[1]                         # is "e" in Py2, but 120 (an integer!) in Py3
+}}}
+
+If you just want to encode a potential {{{unicode}}} instance as an utf-8 encoded {{{str}}}, use {{{s3_str}}} rather than {{{unicode.encode}}}:
+{{{#!python
+# Do this instead (without type-check):
+x = s3_str(x)
+}}}