Changes between Version 1 and Version 2 of Python3Support

Timestamp:

05/21/18 08:26:07 (7 years ago)

Author:

annakrat

Comment:

python scripting lib

Python3Support

@@ -11 +11 @@
 * wxGUI
 
-== Current state of porting
+== Python Scripting Library ==
+Possible approach:
+* functions need to accept unicode and return unicode
+* functions wrapping Python Popen class (read_command, run_command, ...) will have parameter encoding
+ * encoding=None means expects and returns bytes (the current state)
+ * encoding='default' means it takes current encoding using utils._get_encoding()
+ * encoding='utf-8' takes whatever encoding user specifies, e.g., utf-8 in this case
+ * this is similar to [https://docs.python.org/3.6/library/subprocess.html#subprocess.Popen Popen class in Python3.6]
+ * by default encoding='default' to enable expected behavior by users, the following example shows Python3 behavior if we keep using bytes instead of unicode:
+
+{{{
+# return bytes
+ret = read_command('r.what', encoding=None, ...
+
+for item in ret.splitlines():
+    line = item.split('|')[3:]
+
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+TypeError: a bytes-like object is required, not 'str'
+
+# we would have to use:
+for item in ret.splitlines():
+    line = item.split(b'|')[3:]
+}}}