ttk.treeview增加标题单击排序功能

def treeview_sort_column(tv, col, reverse):
l = [(tv.set(k, col), k) for k in tv.get_children('')]
#i = cols.index(col)

#l.sort(key=lambda t: t[i], reverse=reverse)
l.sort(reverse=reverse)
#      ^^^^^^^^^^^^^^^^^^^^^^^

for index, (val, k) in enumerate(l):
tv.move(k, '', index)

tv.heading(col,command=lambda: treeview_sort_column(tv, col, not reverse))

for col in cols:
i = cols.index(col)
#self.mat_list.heading(col, text=tree_head[i])
self.mat_list.heading(col, text=tree_head[i] , command=lambda _col=col: treeview_sort_column(self.mat_list, _col, False))