Common issues we have to look out for

[maweki]

This is just a meta-issue listing the issues we have to look out for, that weren't autotranslated from python 2 to 3

• GObject constructors aren't correctly translated (see Properly instantiate ListView #5)
• Many functions expect int arguments. In python2 a / division between two int always resulted in int. In python3 the result is always float. We have to replace / with // where appropriate. (see fix some float/int mismatch errors #6)
• old-style sort-functions are in use (List.sort()). These need to be replaced with key functions (see use key function for sorting in seconds_to_timestring #9 / recindex.py: sort() takes no positional arguments #7)

Please help add to this list and keep it in mind when touching up code.

[kirienko]

Also:

• some_dict.has_key(x) for dictionaries (→ k in some_dict);
• str.decode() and other utf-related issues.

[kirienko]

A lot of changes related to Gtk, like:

• Gtk.Window: self.app.window → self.app.get_window()
• Gtk.UIManager: get_widget() now takes two arguments (self included), not five

[kirienko]

There's no Gtk.ComboBoxEntry any more. One need to use either ComboBoxText or just ComboBox. This applies also to .ui files.

Details: tutorial and class hierarchy.

[cydanil]

Mea culpa, I commented on another issue. Perhaps it's worth porting all ui files using Glade, but are we targeting GTK3 or 4?

[kirienko]

If a class is used as an exception, it must be derived from Exception. (Strictly speaking, from BaseException but I see no benefits from going to that low level.)

class MyClass(Exception):
    pass

try:
    do_stuff()
except MyClass as e:
    print("That was a bad idea")

[takluyver]

For the integer divisions: I was porting another project some time ago and wanted to find all division operations to check if they were using integers. So I built a little tool called astsearch - you can run astsearch "? / ?" to identify all divisions.