@cvp Thanks a lot to you and to @omz for his unexpected but so wanted comeback !

@mikael Thanks for your reactivity !

Here is my scrolling special key row to replace the standard one.
This script is a mix between @cvpe's script AddButtonsToPythonistaKeyboard https://github.com/cvpe/Pythonista-scripts/blob/master/AddButtonsToPythonistaKeyboard.py
and my own work.
It uses module ui3.sfsymbol of @mikaelho https://github.com/mikaelho/ui3
Thanks for all their work for Pythonista's community.
It certainly contains errors as I am not an expert coder like the majority of you but it does work for me 😉
Feel free to improve and adapt it to your needs!

# =================================================================
# This script is a mix between @cvpe's script AddButtonsToPythonistaKeyboard 
# https://github.com/cvpe/Pythonista-scripts/blob/master/AddButtonsToPythonistaKeyboard.py
# and my own work.
# It uses module ui3.sfsymbol of @mikaelho
# https://github.com/mikaelho/ui3
# 
# enez.houad@free.fr
# =================================================================

import ui, editor, clipboard
from objc_util import *
from ui3.sfsymbol import *

@on_main_thread
def tv_find(tv):
	import console, re
	
	tv.find = console.input_alert('Expression à rechercher :', '', tv.find, hide_cancel_button=True)
	txt = tv.find
	
	for sv in tv.subviews():
		if 'SUIButton_PY3' in str(sv._get_objc_classname()):
			sv.removeFromSuperview()
	if txt == '':
		return
	t = str(tv.text())
	
	for m in re.finditer(txt, t):
		st,en = m.span()
		p1 = tv.positionFromPosition_offset_(tv.beginningOfDocument(), st)
		p2 = tv.positionFromPosition_offset_(tv.beginningOfDocument(), en)
		rge = tv.textRangeFromPosition_toPosition_(p1,p2)
		rect = tv.firstRectForRange_(rge)
		x,y = rect.origin.x,rect.origin.y
		w,h = rect.size.width,rect.size.height
		
		l = ui.Button()
		l.frame = (x,y,w,h)
		if '|' not in txt:
			l.background_color = (1,0,0,0.2)
		else:
			# search multiple strings
			wrds = txt.split('|')
			idx = wrds.index(t[st:en])
			cols = [(1,0,0,0.2), (0,1,0,0.2), (0,0,1,0.2), (1,1,0,0.2), (1,0,1,0.2), (0,1,1,0.2)]
			col = cols[idx % len(cols)]
			l.background_color = col
		l.corner_radius = 4
		l.border_width = 1
		tv.addSubview_(l)		
	
# ———————————————————————————————————————————————————————————————————

def key_pressed(sender):
	
	tv = sender.objc_instance.firstResponder() # associated TextView  
	
	cursor = tv.offsetFromPosition_toPosition_(tv.beginningOfDocument(),     tv.selectedTextRange().start()) # get actual cursor position

	if sender.name == 'tab':
		tv.insertText_('\t')
	
	elif sender.name == 'paste':
		tv.insertText_(clipboard.get())	
		
	elif sender.name == 'undo':
		tv.undoManager().undo()
		
	elif sender.name == 'redo':
		tv.undoManager().redo()
	
	elif sender.name == 'del_right':
		# delete at right = delete at left of next
		if cursor == (len(str(tv.text()))-1): # already after last character
			return
		cursor_position = tv.positionFromPosition_offset_(tv.beginningOfDocument(), cursor+1)
		tv.selectedTextRange = tv.textRangeFromPosition_toPosition_(cursor_position, cursor_position)
		tv.deleteBackward()		
		
	elif sender.name == 'find':
		tv_find(tv)
		
	elif sender.name == 'line-':
		tv.insertText_('# ' + 65 * '—')
	elif sender.name == 'line=':
		tv.insertText_('# ' + 65 * '=')
	elif sender.name == 'line#':
		tv.insertText_(67 * '#')
		
	else: # all other keys > insert button title
		tv.insertText_(sender.title)
	
# ===================================================================
	
class SpecialKeyRow(ui.View):
	
	def __init__(self, pad, *args, **kwargs):
		
		self.pad = pad
	
		sw, sh = ui.get_screen_size()	
		self.uiStyle = ui.get_ui_style()
		
		self.buttonsList = []
		self.buttonWidth = (sw - (2*8) - (24*4)) / 25
		self.buttonHeight = 40
		
		# ———————————————————————————————————————————————————————————————————
		# MAIN VIEW	
	
		self.width, self.height = sw, 50
		self.alpha = 0.98
		
		# ———————————————————————————————————————————————————————————————————
		# SCROLL VIEW
		
		sv = ui.ScrollView(name='scrollview')
		sv.width, sv.height = (sw, 50)
		sv.content_size = (2*sw, 50)
		sv.bounces = False
		sv.shows_horizontal_scroll_indicator = False
		sv.paging_enabled = True
		sv.x, sv.y = (0, 0)
		colorDict = {'light':'#D6D8DD', 'dark':'#343639'}
		sv.background_color = colorDict[self.uiStyle]
		
		self.add_subview(sv)
		
		# ———————————————————————————————————————————————————————————————————
		# BUTTONS IN SCROLL VIEW
		# ———————————————————————————————————————————————————————————————————

		for pad_elem in self.pad:
			if not 'style' in pad_elem: bStyle = 'light'
			else: bStyle = pad_elem['style']
			if 'title' in pad_elem:
				b = self.add_text_button(name=pad_elem['key'], title=pad_elem['title'], style=bStyle)
			elif 'symbol' in pad_elem:
				b = self.add_symbol_button(name=pad_elem['key'], symbol_name=pad_elem['symbol'], style=bStyle)
			self.add_scrollview_button(b)
		
	# ===================================================================
		 
	def add_scrollview_button(self, b):
		b.y = 10
		if self.buttonsList == []: b.x = 8 # 1er bouton
		else:
			lastButton = self.buttonsList[-1]
			b.x = lastButton.x + lastButton.width + 4 # intervalle 4 px
			if len(self.buttonsList) == 25: b.x += 12 # 2e page
		b.action = key_pressed
		retain_global(b)
		self['scrollview'].add_subview(b)
		self.buttonsList.append(b)
			
	# ———————————————————————————————————————————————————————————————————
	
	def add_text_button(self, name='', title='', width=40, style='light'):
		b = self.add_button(name, style)
		b.title = title
		b.font = ('<system>', 18)
		if width == None: b.width = ui.measure_string(b.title,font=b.font)[0] + 28
		else: b.width = self.buttonWidth		
		return b
		
	# ———————————————————————————————————————————————————————————————————
	
	def add_symbol_button(self, name='', symbol_name='', style='light'):
		b = self.add_button(name, style)
		symbol_image = SymbolImage(symbol_name, point_size=11, weight=LIGHT, scale=SMALL)
		b.image = symbol_image	
		b.width = self.buttonWidth	
		return b
		
	# ———————————————————————————————————————————————————————————————————
	
	def add_button(self, name='', backgroundStyle='light'):
		
		b = ui.Button(name=name)
		b.corner_radius = 8
		
		colorsDict = {	'light'	:({'light':'#FFFFFF', 'dark':'#B4B9C1'}, 'black'), 
						'dark'	:({'light':'#717274', 'dark':'#4D4F50'}, 'white') }
		b.background_color = colorsDict[self.uiStyle][0][backgroundStyle]
		b.tint_color = colorsDict[self.uiStyle][1]
		
		b.alpha = self.alpha
		
		b.font = ('<system>', 18)
		b.height = self.buttonHeight		
		return b
				
# ===================================================================

@on_main_thread
def AddButtonsToPythonistaKeyboard(pad=None):
	
	def numeric_keys(): 
		list = []
		for i in range(1, 10):
			list.append({'key':str(i), 'title':str(i)})
		list.append({'key':'0', 'title':'0'})
		return list
		
	if not pad:		
		pad = [
				{'key':'tab', 'symbol':'arrow.right.to.line.alt'},				
			
				{'key':'undo', 'symbol':'arrow.uturn.left', 'style':'dark'},
				{'key':'redo','symbol':'arrow.uturn.right', 'style':'dark'},
				
				{'key':'paste', 'symbol':'doc.on.clipboard'},
			
				{'key':'#', 'title':'#'},
				{'key':'_', 'title':'_'},
			
				{'key':"'", 'title':"'"},
				{'key':'"', 'title':'"'},
				{'key':"'''", 'title':"'''"},
			
				{'key':'(', 'title':'('},
				{'key':')', 'title':')'},			
				{'key':'[', 'title':'['},
				{'key':']', 'title':']'},
				{'key':'{', 'title':'{'},
				{'key':'}', 'title':'}'},
			
				{'key':'+', 'title':'+'},
				{'key':'-', 'title':'-'},
				{'key':'*', 'title':'*'},
				{'key':'/', 'title':'/'},
				{'key':"\\", 'title':"\\"},
			
				{'key':'<', 'title':'<'},
				{'key':'>', 'title':'>'},
				{'key':'=', 'title':'='},
				{'key':':', 'title':':'},
			
				{'key':'del_right', 'symbol':'delete.right', 'style':'dark'},
			
				{'key':'find', 'symbol':'magnifyingglass', 'style':'dark'}
				]
				
		pad += numeric_keys() 
		
		pad += [
				{'key':'+', 'title':'+'},
				{'key':'-', 'title':'-'},
				{'key':'*', 'title':'*'},
				{'key':'/', 'title':'/'},
				{'key':'<', 'title':'<'},
				{'key':'>', 'title':'>'},
				{'key':'=', 'title':'='},
			
				{'key':'line-', 'title':'---'},
				{'key':'line=', 'title':'==='},
				{'key':'line#', 'title':'###'}
				]	
		
	ev = editor._get_editor_tab().editorView()
	tv = ev.textView()
	
	v = SpecialKeyRow(pad)                        
	vo = ObjCInstance(v)  

	retain_global(v)
	
	tv.setInputAccessoryView_(vo)   # attach accessory to textview
	tv.find = ''
	
# ===================================================================
	
if __name__ == '__main__':
	AddButtonsToPythonistaKeyboard() ```

@mikael, Perfect 👏👏🙏👍
Thank you very much, I would find it hard to do without Scripter!

That's it, I did it! I just had forgotten to delete the original stash.launch !

I’ve go the obj exception :

The app was terminated due to an Objective-C exception. Details below:

2023-01-25 22:48:24.867065
Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread.

But I don’t understand what it meens !

@cvp Yes, but on my iPad mini 4 running ipadOS 15.7.3, I get a crash when I run launch_stash.

I’ve tried wrapping in_background as recommended with :

import ui
@ui.in_background()
def launch(*args):
_stash.launch(*args)

launch(ns.command)

but I still get a crash !

@cvp Exact, I’ve found it ! I’ve done a clean install of Pythonista 3.4 beta and at the moment I'm struggling to reinstall Slash and it's not easy ;-) but I will win !

@cvp Thanks a lot to you and to @omz for his unexpected but so wanted comeback !

@cvp So, now I need to put my own content of my old site-packages-3 in the site-packages, exact ?

In 3 3.4 (340006) beta on my iPad mini 4 iPadOS 15.7.3 the folder site-packages-3 is not visible in Python Modules.

@mikael Thanks for your reactivity !

@mikael , I regularly use your modules and I thank you for it. Unfortunately, since the last version of ui3, I have an error when I want to use it.
Here is the Traceback :

Traceback (most recent call last):
  File "/private/var/mobile/Library/Mobile Documents/iCloud~com~omz-software~Pythonista3/Documents/ui3-master/sheet.py", line 7, in <module>
    from ui3.anchor import *
  File "/private/var/mobile/Library/Mobile Documents/iCloud~com~omz-software~Pythonista3/Documents/ui3-master/ui3/__init__.py", line 12, in <module>
    from ui3.anchor import *
  File "/private/var/mobile/Library/Mobile Documents/iCloud~com~omz-software~Pythonista3/Documents/ui3-master/ui3/anchor/__init__.py", line 821, in <module>
    via_screen,
NameError: name 'via_screen' is not defined ```

@cvp Thanks a lot ! I’m happy to see that I progress slowly…
I had found textView().becomeFirstResponder() but couldn’t find to witch element it had to be applied. The _get_editor_tab is not documented ! To find it, do you open editor.py in the site-packages of Standard Library ?
It's very instructive 🤓, I'm going to end up managing on my own. 😉