Как добавить 2 полосы прокрутки с tkinter в python 3.4?

Question

У меня есть следующий код:

from win32com.client import Dispatch 
from tkinter import * 
from tkinter import ttk 
import tkinter 

class applicazione: 

def __init__(self, root): 
    self.root = root 
    self.root.title('Controllo dati per fatturazione elettronica - Manticle - Smith & Nephew Italia') 
    ttk.Frame(self.root, width=300, height=250).pack() 






    #### label list 
    self.titoli = list() 
    self.titoli_BFT = ["Num_Doc", "Cod_Art", "Unita Misura", "Tot_Prod", "Quant_Prod", "Perc_IVA_Prod", "Tot_IVA_Prod", 
         "Linea_Prod", "Sconto", "Perc_Sconto", "Tipo_Sconto", "Cod_Art2", "Desc_Art"] 
    self.titoli_HFT = ["Dest_Cod_FIS_P_Iva", "Cod_Cli", "Dest_RagSoc1", "Dest_RagSoc2", 
         "Dest_Indirizzo", "Dest_CAP", "Dest_Localita", "Dest_Provincia", "Cli_Cod_Fis_P_Iva", 
         "Cod_Dest", "Cli_RagSoc1", "Cli_RagSoc2", "Cli_Indirizzo", "Cli_CAP", 
         "Cli_Localita", "Cli_Provincia", "Tipo_Doc", "pre_Num_Doc", "Num_Doc", 
         "Data_Doc", "Vs_Rif", "Data_Rif", "Blank", "Blank2", "CPT", "Scad_Pagamento", 
         "Descr", "Num_Ord", "Tot_Imp", "Tot_IVA", "Tot_Doc", "Nazione", "IPA", "Reg_Fiscale"] 

    self.titoli_IVA = ["Num_Doc_TMP", "Num_Doc", "Imponibile", "IVA, Tot", "Perc_IVA"] 

    self.titoli_RIF_DOC = [ "Num_Doc_TMP", "Num_Doc", "Rif_Doc" ] 

    self.titoli_RIF_DOC_BFT = ["Num_Doc_TMP", "Num_Doc", "Cod_Art", "NOTE" ] 

    self.titoli_anomalieBFT = ["ordine", "anomalia"] 

    self.titoli_anomalieHFT = ["ordine", "anomalia"] 

    self.inizializza_widgets() 
    self.lettura() 



def inizializza_widgets(self): 
    #label 

    self.lblins=tkinter.Label(self.root, text="Controllo dati per fatturazione elettronica", font=("Helvetica", 12)) 
    self.lblins.place(x=10, y=10 



    for i in range (0,len(self.titoli_HFT)): 
     j = 80*i 
     self.lblnome=tkinter.Label(self.root, text= self.titoli_HFT[i], font=("Helvetica", 8)) 
     self.lblnome.place(x=85+j, y=50) 


    #buttons 

    ttk.Button(self.root, , text='Inserisci', width='10').place(x=645, y=590) 
    #pulsante lettura 
    ttk.Button(self.root, text='Modifica', width='10').place(x=725, y=590) 

    ttk.Button(self.root, text='Indietro', width='10').place(x=805, y=590) 

    ttk.Button(self.root, text='Avanti', width='10').place(x=885, y=590) 


def onFrameConfigure(self, event): 
    '''Reset the scroll region to encompass the inner frame''' 
    self.canvas.configure(scrollregion=self.canvas.bbox("all")) 

def lettura(self): 
     xl= Dispatch("Excel.Application") 
     xl.Visible = True 


     self.checkb_intvar = list() #contiene una lista di 1 o 0 associati alle checkbox nella lista quadratini 
     self.quadratiniB = l = [None] * (13 * len(self.titoli_BFT)) 
     self.quadratiniH = l = [None] * (13 * len(self.titoli_HFT)) 


     wbH = xl.Workbooks.Open(r'C:\Users\\Marco\\LAVORO\\Smith&Nephew\\appRonca\\fonte\\HFT_SAP_2.csv') 
     print("wbH") 

     wsH=wbH.WorkSheets(1) # get a reference to the first sheet 


     cont = 0 

     MAX = 3 #13 lunghezza visibile senza barra navigatrice del numero di righe nella finestra 13 
     cont = 0 
     for i in range(0, MAX): 
      for j in range(0,len(self.titoli_HFT)): 
       print("for for") 
       cont = cont + 1 
       print("i") 
       print(i) 
       print("j") 
       print(j) 

       print(" The {} set is often represented as {{0}} ".format("empty")) 


       #### indexes for DI excel cells management 
       k = 80*j  #i con j 
       l = 40*i  #k con l 


       contvalueX = i + 1 #con zero da errore allora +1 
       contvalueY = j + 1 #con zero da errore allora +1 

       self.txt1 = tkinter.Text(self.root, width='10', height='1') 


       #Reading excel cells file 

       if (wsH.Cells(contvalueX, contvalueY).Value != None): 

        self.txt1.insert('1.0', wsH.Cells(contvalueX, contvalueY).Value)#ws.Cells(1,i).Value 
        self.txt1.tag_add("start", "1.0", "1.13") 
        if (contvalueY == 1): 
         self.txt1.tag_config("start", background="white", foreground="red") 
        #self.txt1.tag_configure("red", foreground="red") 
        #self.txt1.highlight_pattern("word", "red") 
        #self.txt1 = tkinter.Text(self.root, width='10', height='1', text = ws.Cells(1,i).Value) 
        self.txt1.place(x=85+k, y=80+l) #5 + 80 
        print("if") 

       else: #None case 
        print("else") 
        self.txt1.insert('1.0', "") 
        self.txt1.place(x=85+k, y=80+l) 
        if (contvalueY == 1): 
         self.txt1.tag_config("start", background="white", foreground="red") 




     wbH.Close() 
     xl.Quit() 


if __name__ == '__main__': 
    root = tkinter.Tk() 
    w, h = root.winfo_screenwidth(), root.winfo_screenheight() 
    root.geometry("%dx%d+0+0" % (w, h)) 
    applicazione(root) 
    root.mainloop() 

запущенной Применение:

Я читать данные из файла Excel (функция lettura) , но я хотел бы добавить горизонтальную и вертикальная полоса прокрутки, которую я читаю в первую очередь:

Adding a scrollbar to a group of widgets in Tkinter

но используйте «сетку», которую я не использую, и я не могу связать свой двойной «для» «текст» с вертикальной полосой прокрутки (функция Lettura)

Следующий код редактируется с помощью полосы прокрутки, но не работает:

import tkinter as tk 

from win32com.client import Dispatch 
from tkinter import * 
#from tkinter import ttk 
import tkinter 

class Example(tk.Frame): 
    def __init__(self, root): 

     tk.Frame.__init__(self, root) 
     root.title('Controllo dati per fatturazione elettronica - Manticle - Smith & Nephew Italia') 
     #tk.Frame(root, width=100, height=450).pack() 



     self.canvas = tk.Canvas(root, borderwidth=0, background="#C0C0C0") 
     self.frame = tk.Frame(self.canvas, background="#ffffff") 
     self.vsb = tk.Scrollbar(root, orient="vertical", command=self.canvas.yview) 
     self.canvas.configure(yscrollcommand=self.vsb.set) 

     self.vsb.pack(side="right", fill="y") 
     self.canvas.pack(side="left", fill="both", expand=True) 
     self.canvas.create_window((4,4), window=self.frame, anchor="nw", 
            tags="self.frame") 

     self.frame.bind("<Configure>", self.onFrameConfigure) 


     self.titoli_BFT = ["Num_Doc", "Cod_Art", "Unita Misura", "Tot_Prod", "Quant_Prod", "Perc_IVA_Prod", "Tot_IVA_Prod", 
          "Linea_Prod", "Sconto", "Perc_Sconto", "Tipo_Sconto", "Cod_Art2", "Desc_Art"] 

     self.titoli_HFT = ["Dest_Cod_FIS_P_Iva", "Cod_Cli", "Dest_RagSoc1", "Dest_RagSoc2", 
          "Dest_Indirizzo", "Dest_CAP", "Dest_Localita", "Dest_Provincia", "Cli_Cod_Fis_P_Iva", 
          "Cod_Dest", "Cli_RagSoc1", "Cli_RagSoc2", "Cli_Indirizzo", "Cli_CAP", 
          "Cli_Localita", "Cli_Provincia", "Tipo_Doc", "pre_Num_Doc", "Num_Doc", 
          "Data_Doc", "Vs_Rif", "Data_Rif", "Blank", "Blank2", "CPT", "Scad_Pagamento", 
          "Descr", "Num_Ord", "Tot_Imp", "Tot_IVA", "Tot_Doc", "Nazione", "IPA", "Reg_Fiscale"] 


     #self.inizializza_widgets() 
     self.populate() 
     self.lettura() 




    def inizializza_widgets(self): 
     #label title 

     self.lblins=tk.Label(root, text="Controllo dati per fatturazione elettronica", font=("Helvetica", 12)) 
     self.lblins.place(x=10, y=10) 



     for i in range (0,len(self.titoli_HFT)): 
      j = 80*i 
      self.lblnome=tk.Label(root, text= self.titoli_HFT[i], font=("Helvetica", 8)) 
      self.lblnome.place(x=85+j, y=50) 


     #965 560 
     tk.Button(root, text='Inserisci', width='10').place(x=645, y=590) 
     #pulsante lettura 
     tk.Button(root, text='Modifica', width='10').place(x=725, y=590) 

     tk.Button(root, text='Indietro', width='10').place(x=805, y=590) 

     tk.Button(root, text='Avanti', width='10').place(x=885, y=590) 


    def lettura(self): 
      xl= Dispatch("Excel.Application") 
      xl.Visible = True 

      wbH = xl.Workbooks.Open(r'C:\Users\\Marco\\LAVORO\\Smith&Nephew\\appRonca\\fonte\\HFT_SAP_2.csv') 
      print("wbH") 

      wsH=wbH.WorkSheets(1) # get a reference to the first sheet 



      cont = 0 

      MAX = 9 #13 lunghezza visibile senza barra navigatrice del numero di righe nella finestra 13 
      cont = 0 







      for i in range(0, MAX): 
       for j in range(0,len(self.titoli_HFT)): 
        print("for for") 
        cont = cont + 1 

        print("cont") 
        print(cont) 

        #### INDEXES 
        k = 80*j  #i con j 
        l = 40*i  #k con l 


        contvalueX = i + 1 #con zero da errore allora +1 
        contvalueY = j + 1 #con zero da errore allora +1 

        self.txt1 = tk.Text(root, width='10', height='1') 




        #Lettura celle del file HFT 

        if (wsH.Cells(contvalueX, contvalueY).Value != None): 

         self.txt1.insert('1.0', wsH.Cells(contvalueX, contvalueY).Value)#ws.Cells(1,i).Value 
         self.txt1.tag_add("start", "1.0", "1.13") 
         if (contvalueY == 1): 
          self.txt1.tag_config("start", background="white", foreground="red") 

         self.txt1.place(x=85+k, y=80+l) #5 + 80 
         print("if") 

        else: #None case 
         print("else") 
         self.txt1.insert('1.0', "") 
         self.txt1.place(x=85+k, y=80+l) 
         if (contvalueY == 1): #### qui si richiama la funziona regole con tutte le regole 
          self.txt1.tag_config("start", background="white", foreground="red") 

      wbH.Close() 
      xl.Quit() 



    def onFrameConfigure(self, event): 
     '''Reset the scroll region to encompass the inner frame''' 
     self.canvas.configure(scrollregion=self.canvas.bbox("all")) 

if __name__ == "__main__": 
    root=tk.Tk() 
    Example(root).pack(side="top", fill="both", expand=True) 
    root.mainloop() 

и это: How to add a scrollbar to a window with tkinter? , не организовать как класс.

Как я могу реализовать 2 полосы прокрутки?

UPDATE

новая версия:

from win32com.client import Dispatch 
from tkinter import * 
from tkinter import ttk 
import tkinter 


class applicazione: 


    def __init__(self, root): 
     self.root = root 

     # Top-level frame 

     self.frame = ttk.Frame(self.root, relief="sunken") 

     # Canvas creation with double scrollbar 
     hscrollbar = ttk.Scrollbar(self.frame, orient = tkinter.HORIZONTAL) 
     vscrollbar = ttk.Scrollbar(self.frame, orient = tkinter.VERTICAL) 
     self.canvas = tkinter.Canvas(self.frame, bd=0, highlightthickness=0, yscrollcommand = vscrollbar.set, xscrollcommand = hscrollbar.set) 
     vscrollbar.config(command = self.canvas.yview) 
     hscrollbar.config(command = self.canvas.xview) 


     # Add controls here 
     self.subframe = ttk.Frame(self.canvas) 

     #Packing everything 
     self.subframe.pack(padx = 15, pady = 15, fill = tkinter.BOTH, expand = tkinter.TRUE) 
     hscrollbar.pack(fill=tkinter.X, side=tkinter.BOTTOM, expand=tkinter.FALSE) 
     vscrollbar.pack(fill=tkinter.Y, side=tkinter.RIGHT, expand=tkinter.FALSE) 
     self.canvas.pack(side = tkinter.LEFT, padx = 5, pady = 5, fill = tkinter.BOTH, expand= tkinter.TRUE) 
     self.frame.pack(padx = 5, pady = 5, expand = True, fill = tkinter.BOTH) 


     self.canvas.create_window(0,0, window = self.subframe) 
     self.root.update_idletasks() # update geometry 
     self.canvas.config(scrollregion = self.canvas.bbox("all")) 
     self.canvas.xview_moveto(0) 
     self.canvas.yview_moveto(0) 


     self.root.title('Controllo dati per fatturazione elettronica - Manticle - Smith & Nephew Italia') 
     ttk.Frame(self.root, width=300, height=250).pack() 


     #### Titles 
     self.titoli_HFT = ["Dest_Cod_FIS_P_Iva", "Cod_Cli", "Dest_RagSoc1", "Dest_RagSoc2", 
          "Dest_Indirizzo", "Dest_CAP", "Dest_Localita", "Dest_Provincia", "Cli_Cod_Fis_P_Iva", 
          "Cod_Dest", "Cli_RagSoc1", "Cli_RagSoc2", "Cli_Indirizzo", "Cli_CAP", 
          "Cli_Localita", "Cli_Provincia", "Tipo_Doc", "pre_Num_Doc", "Num_Doc", 
          "Data_Doc", "Vs_Rif", "Data_Rif", "Blank", "Blank2", "CPT", "Scad_Pagamento", 
          "Descr", "Num_Ord", "Tot_Imp", "Tot_IVA", "Tot_Doc", "Nazione", "IPA", "Reg_Fiscale"] 



     self.inizializza_widgets() 


    def inizializza_widgets(self): 

     self.lblins=tkinter.Label(self.root, text="Controllo dati per fatturazione elettronica", font=("Helvetica", 12)) 
     self.lblins.place(x=10, y=10) 

     for i in range (0,len(self.titoli_HFT)): 
      j = 80*i 
      self.lblnome=tkinter.Label(self.root, text= self.titoli_HFT[i], font=("Helvetica", 8)) 
      self.lblnome.place(x=85+j, y=50) 

     ttk.Button(self.root, text='Inserisci', width='10').place(x=645, y=590) 

     ttk.Button(self.root, text='Modifica', width='10').place(x=725, y=590) 

     ttk.Button(self.root, text='Indietro', width='10').place(x=805, y=590) 

     ttk.Button(self.root, text='Avanti', width='10').place(x=885, y=590) 



if __name__ == '__main__': 
    root = tkinter.Tk() 
    root.title("Double scrollbar with tkinter") 
    w, h = root.winfo_screenwidth(), root.winfo_screenheight() 
    root.geometry("%dx%d+0+0" % (w, h)) 
    applicazione(root) 
    root.mainloop() 

Answer 1

Я также боролся с созданием двойного окна прокрутки. Вот реализация с помощью pack менеджер компоновки (вы должны быть в состоянии адаптировать его для grid макета):

import tkinter as tk 
from tkinter import ttk 

# Top-level frame 
root = tk.Tk() 
root.title("Double scrollbar with tkinter") 
root.minsize(width = 600, height = 600) 
frame = ttk.Frame(root, relief="sunken") 

# Canvas creation with double scrollbar 
hscrollbar = ttk.Scrollbar(frame, orient = tk.HORIZONTAL) 
vscrollbar = ttk.Scrollbar(frame, orient = tk.VERTICAL) 
sizegrip = ttk.Sizegrip(frame) 
canvas = tk.Canvas(frame, bd=0, highlightthickness=0, yscrollcommand = vscrollbar.set, xscrollcommand = hscrollbar.set) 
vscrollbar.config(command = canvas.yview) 
hscrollbar.config(command = canvas.xview) 


# Add controls here 
subframe = ttk.Frame(canvas) 

#Packing everything 
subframe.pack(padx = 15, pady = 15, fill = tk.BOTH, expand = tk.TRUE) 
hscrollbar.pack(fill=tk.X, side=tk.BOTTOM, expand=tk.FALSE) 
vscrollbar.pack(fill=tk.Y, side=tk.RIGHT, expand=tk.FALSE) 
sizegrip.pack(in_ = hscrollbar, side = tk.BOTTOM, anchor = "se") 
canvas.pack(side = tk.LEFT, padx = 5, pady = 5, fill = tk.BOTH, expand= tk.TRUE) 
frame.pack(padx = 5, pady = 5, expand = True, fill = tk.BOTH) 


canvas.create_window(0,0, window = subframe) 
root.update_idletasks() # update geometry 
canvas.config(scrollregion = canvas.bbox("all")) 
canvas.xview_moveto(0) 
canvas.yview_moveto(0) 


# launch the GUI 
root.mainloop() 

(Испытано с Python 3.4).

Exemples:

Это не совершенна, так как ему не хватает небольшой блок в правом нижнем углу.

UPDATE 1: Добавлено Sizegrip получить в правом нижнем углу изменения размера углу

UPDATE 2: Добавлен рабочий раствор для обновленного кода OP в

from win32com.client import Dispatch 
from tkinter import * 
from tkinter import ttk 
import tkinter 


class applicazione(object): 


    def __init__(self, root): 
     self.root = root 

     # Top-level frame 
     self.root.title('Controllo dati per fatturazione elettronica - Manticle - Smith & Nephew Italia') 

     self.frame = ttk.Frame(self.root, width=300, height=250) 

     # Canvas creation with double scrollbar 
     hscrollbar = ttk.Scrollbar(self.frame, orient = tkinter.HORIZONTAL) 
     vscrollbar = ttk.Scrollbar(self.frame, orient = tkinter.VERTICAL) 
     sizegrip = ttk.Sizegrip(self.frame) 
     self.canvas = tkinter.Canvas(self.frame, bd=0, highlightthickness=0, yscrollcommand = vscrollbar.set, xscrollcommand = hscrollbar.set) 
     vscrollbar.config(command = self.canvas.yview) 
     hscrollbar.config(command = self.canvas.xview) 


     # Add controls here 
     self.subframe = ttk.Frame(self.canvas)   


     #### Titles 
     self.titoli_HFT = ["Dest_Cod_FIS_P_Iva", "Cod_Cli", "Dest_RagSoc1", "Dest_RagSoc2", 
          "Dest_Indirizzo", "Dest_CAP", "Dest_Localita", "Dest_Provincia", "Cli_Cod_Fis_P_Iva", 
          "Cod_Dest", "Cli_RagSoc1", "Cli_RagSoc2", "Cli_Indirizzo", "Cli_CAP", 
          "Cli_Localita", "Cli_Provincia", "Tipo_Doc", "pre_Num_Doc", "Num_Doc", 
          "Data_Doc", "Vs_Rif", "Data_Rif", "Blank", "Blank2", "CPT", "Scad_Pagamento", 
          "Descr", "Num_Ord", "Tot_Imp", "Tot_IVA", "Tot_Doc", "Nazione", "IPA", "Reg_Fiscale"] 



     self.inizializza_widgets() 

     #Packing everything 
     self.subframe.pack(fill = tkinter.BOTH, expand = tkinter.TRUE) 
     hscrollbar.pack(fill=tkinter.X, side=tkinter.BOTTOM, expand=tkinter.FALSE) 
     vscrollbar.pack(fill=tkinter.Y, side=tkinter.RIGHT, expand=tkinter.FALSE) 
     sizegrip.pack(in_= hscrollbar, side = BOTTOM, anchor = "se") 
     self.canvas.pack(side = tkinter.LEFT, padx = 5, pady = 5, fill = tkinter.BOTH, expand= tkinter.TRUE) 
     self.frame.pack(padx = 5, pady = 5, expand = True, fill = tkinter.BOTH) 


     self.canvas.create_window(0,0, window = self.subframe) 
     self.root.update_idletasks() # update geometry 
     self.canvas.config(scrollregion = self.canvas.bbox("all")) 
     self.canvas.xview_moveto(0) 
     self.canvas.yview_moveto(0)  


    def inizializza_widgets(self): 

     self.LabelFrame = ttk.Frame(self.subframe) 
     self.lblins = tkinter.Label(self.LabelFrame, text="Controllo dati per fatturazione elettronica", font=("Helvetica", 12)) 
     self.lblins.pack() 

     for i in range (0,len(self.titoli_HFT)): 
      j = 80*i 
      self.lblnome=tkinter.Label(self.LabelFrame, text= self.titoli_HFT[i], font=("Helvetica", 8)) 
      self.lblnome.pack(side = LEFT)#place(x=85+j, y=50) 

     self.ContentFrame = ttk.Frame(self.subframe, width = 600, height = 600) 

     self.ButtonsFrame = ttk.Frame(self.subframe) 
     ttk.Frame(self.ButtonsFrame).pack(side=LEFT, fill = X, expand=TRUE) 
     ttk.Button(self.ButtonsFrame, text='Inserisci', width='10').pack(side = LEFT) 
     ttk.Button(self.ButtonsFrame, text='Modifica', width='10').pack(side = LEFT) 
     ttk.Button(self.ButtonsFrame, text='Indietro', width='10').pack(side = LEFT) 
     ttk.Button(self.ButtonsFrame, text='Avanti', width='10').pack(side = LEFT) 
     ttk.Frame(self.ButtonsFrame).pack(side=RIGHT, fill = X, expand=TRUE) 

     self.LabelFrame.pack(side = TOP, fill = X, expand=TRUE) 
     self.ContentFrame.pack(fill = BOTH, expand = TRUE) 
     self.ButtonsFrame.pack(side = BOTTOM, fill = X, expand = TRUE) 



if __name__ == '__main__': 
    root = tkinter.Tk() 
    root.title("Double scrollbar with tkinter") 
    w, h = root.winfo_screenwidth(), root.winfo_screenheight() 
    root.geometry("%dx%d+0+0" % (0.99*w, 0.9*h)) 
    applicazione(root) 


    root.mainloop() 

Answer 2

Процесс добавления как горизонтальная, так и вертикальная полоса прокрутки для коллекции виджетов точно такая же, как и решение, представленное в этом ответе: https://stackoverflow.com/a/3092341/7432. Этот ответ показывает только вертикальную полосу прокрутки, но добавление горизонтального - это всего лишь пара строк кода.

Решение очень прямолинейно:

• добавить виджеты к каркасу с помощью любого метода вы хотите
• добавить рамку на холст, используя create_window метод холста
• добавить полосы прокрутки полотно обычным способом
• установить атрибут scrollregion на холсте, чтобы он был достаточно большим, чтобы добавить весь кадр, который был добавлен
  • делать это всякий раз, когда вы добавляете или удалять виджеты из кадра
  • вы также должны делать это каждый раз, когда изменяется размер холста

Answer 3

Просто расширить ответ на @georgesl и продемонстрировать использование ttk sizegrip, а также показать, что grid прекрасно работает для такого рода задач, вот краткий пример, показывающий текстовый виджет с 2 полосами прокрутки и sizegrip в углу.

# Demonstrate text widget with two scrollbars and the sizegrip. 
import tkinter as tk 
import tkinter.ttk as ttk 

root = tk.Tk() 
text = tk.Text(root) 
vs = ttk.Scrollbar(root, orient="vertical") 
hs = ttk.Scrollbar(root, orient="horizontal") 
sizegrip = ttk.Sizegrip(root) 

# hook up the scrollbars to the text widget 
text.configure(yscrollcommand=vs.set, xscrollcommand=hs.set, wrap="none") 
vs.configure(command=text.yview) 
hs.configure(command=text.xview) 

# grid everything on-screen 
text.grid(row=0,column=0,sticky="news") 
vs.grid(row=0,column=1,sticky="ns") 
hs.grid(row=1,column=0,sticky="news") 
sizegrip.grid(row=1,column=1,sticky="news") 
root.grid_rowconfigure(0, weight=1) 
root.grid_columnconfigure(0, weight=1) 

def fill(): 
    for n in range(30): 
     text.insert("end", 'hello ' * 20, "", "\n") 
root.after(20, fill) 
root.mainloop()