如何在 tkinter Text 小部件中实现查找和替换功能？

Question

I have the following code:

def find_and_replace(self, *args):

        findandreplace = tk.Toplevel(master)
        findandreplace.title('Find & Replace')

        find_label = tk.Label(findandreplace, text='Find')
        find_label.pack(side = tk.LEFT) 
        find_words = tk.StringVar()
        find_entry = tk.Entry(findandreplace, textvariable=find_words)
        find_entry.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)

        find_button = tk.Button(findandreplace, text='Find', command=self.find)
        find_button.pack(side = tk.LEFT)

        replace_label = tk.Label(findandreplace, text='Replace')
        replace_label.pack(side = tk.LEFT) 
        replace_words = tk.StringVar()
        replace_entry = tk.Entry(findandreplace, textvariable=replace_words)
        replace_entry.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
        
        replace_button = tk.Button(findandreplace, text='Replace', command=self.replace)
        replace_button.pack(side = tk.LEFT)

        find_string = find_words.get()
        replace_string = replace_words.get()

        return find_string, replace_string

    
    def find(self, *args):
        self.textarea.tag_remove('found', '1.0', tk.END)
        find_word = self.find_and_replace()[0]
        if find_word:
            idx = '1.0'
            while True:
                idx = self.textarea.search(find_word, idx, nocase=1,
                                            stopindex=tk.END)

                if not idx:
                    break

                lastidx = '% s+% dc' % (idx, len(find_word))
                idx = lastidx
            self.textarea.tag_config('found', foreground='red')
    
    def replace(self, *args):
        self.textarea.tag_remove('found', '1.0', tk.END)
        find_word = self.find_and_replace()[0]
        replace_word = self.find_and_replace()[1]

        if find_word and replace_word:
            idx = '1.0'
            while True:
                idx = self.textarea.search(find_word, idx, nocase=1,
                                            stopindex=tk.END)
                if not idx:
                    break

                lastidx = '% s+% dc' % (idx, len(find_word))
                self.textarea.delete(idx, lastidx)
                self.textarea.insert(idx, replace_word)

                lastidx = '% s+% dc' % (idx, len(replace_word))
                idx = lastidx
            self.textarea.tag_config('found', foreground='green', background='yellow')

And I am using a menubar in a different class to access this:

edit_dropdown.add_command(label="Find",
                          command=parent.find)     
edit_dropdown.add_command(label="Replace",
                          command=parent.find_and_replace)

So, find_and_replace() creates a new tk.Toplevel widget where I can access the find() and replace() functions.

However, when I press on the respective buttons, all I get is two more windows created. I want to highlight the find_words string and then have it replaced by the replace_words string.

I feel I'm messing up by accessing variables of one method in another and in the opposite manner.

Answer 1

The root of your problem are these lines:

find_word = self.find_and_replace()[0]
replace_word = self.find_and_replace()[1]

self.find_and_replace creates the dialog. You don't want to be creating new dialogs. Instead, you need to access the widgets in the current dialog. That means you need to save references to the widgets as instance attributes, and then use those instance attributes.

Note: you can reduce the complexity by not using the textvariable attribute. You're just adding overhead since you aren't taking advantage of any features of the variable that you can't do by just calling the entry widget directly

For example:

def find_and_replace(self, *args):
    ...
    self.find_entry = tk.Entry(findandreplace)
    self.replace_entry = tk.Entry(findandreplace)
    ...

def replace(self, *args):
    ...
    find_word = self.find_entry.get()
    replace_word = self.replace_entry.get()
    ...

Answer 2

Something like this should do the trick:

from tkinter import *
  
  
# to create a window  
root = Tk()  
  
# root window is the parent window  
fram = Frame(root)  
  
# Creating Label, Entry Box, Button  
# and packing them adding label to 
# search box  
Label(fram, text ='Find').pack(side = LEFT) 
  
# adding of single line text box  
edit = Entry(fram)  
  
# positioning of text box  
edit.pack(side = LEFT, fill = BOTH, expand = 1)  
  
# setting focus  
edit.focus_set()  
  
# adding of search button  
Find = Button(fram, text ='Find') 
Find.pack(side = LEFT) 
  
  
Label(fram, text = "Replace With ").pack(side = LEFT) 
  
edit2 = Entry(fram) 
edit2.pack(side = LEFT, fill = BOTH, expand = 1) 
edit2.focus_set() 
  
replace = Button(fram, text = 'FindNReplace') 
replace.pack(side = LEFT) 
  
fram.pack(side = TOP)  
  
# text box in root window  
text = Text(root)  
  
# text input area at index 1 in text window  
text.insert('1.0', '''Type your text here''')  
text.pack(side = BOTTOM)  
  
# function to search string in text  
def find():  
    # remove tag 'found' from index 1 to END  
    text.tag_remove('found', '1.0', END)  
      
    # returns to widget currently in focus  
    s = edit.get() 
      
    if (s):  
        idx = '1.0'
        while 1:  
            # searches for desried string from index 1  
            idx = text.search(s, idx, nocase = 1,  
                            stopindex = END) 
              
            if not idx: break
            # last index sum of current index and  
            # length of text  
            lastidx = '% s+% dc' % (idx, len(s)) 
  
            # overwrite 'Found' at idx  
            text.tag_add('found', idx, lastidx)  
            idx = lastidx  
  
        # mark located string as red 
          
        text.tag_config('found', foreground ='red') 
    edit.focus_set() 
  
def findNreplace():  
    # remove tag 'found' from index 1 to END  
    text.tag_remove('found', '1.0', END)  
      
    # returns to widget currently in focus  
    s = edit.get() 
    r = edit2.get() 
      
    if (s and r):  
        idx = '1.0'
        while 1:  
            # searches for desried string from index 1  
            idx = text.search(s, idx, nocase = 1,  
                            stopindex = END) 
            print(idx) 
            if not idx: break
              
            # last index sum of current index and  
            # length of text  
            lastidx = '% s+% dc' % (idx, len(s)) 
  
            text.delete(idx, lastidx) 
            text.insert(idx, r) 
  
            lastidx = '% s+% dc' % (idx, len(r)) 
              
            # overwrite 'Found' at idx  
            text.tag_add('found', idx, lastidx)  
            idx = lastidx  
  
        # mark located string as red 
        text.tag_config('found', foreground ='green', background = 'yellow') 
    edit.focus_set() 
                  
Find.config(command = find) 
replace.config(command = findNreplace) 
  
# mainloop function calls the endless  
# loop of the window, so the window will 
# wait for any user interaction till we 
# close it  
root.mainloop()