Python Tkinter GUI program for multi line text entery box by text

We will keep one Label along with a text box.
Basics of Python Tkinter

Tkinter Text style & to read input & display text on click event of button by get() & set() methods

User input for multiline of text. ( for single line of text use Entry)

t1=tk.Text(parent_window,options)

parent_window : Declared Parent window
options : Various options can be added, list is given below.

import tkinter as tk
my_w = tk.Tk()
my_w.geometry("500x500")  

l1 = tk.Label(my_w,  text='Your Name', width=10 )  # added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,  height=1, width=8,bg='yellow') # added one text box
t1.grid(row=1,column=2) 

my_w.mainloop()

To manage layout read more on grid()

Total number of chars inside the Text widget

Reading data of text box starting from first char till end

t1.get("1.0",END)

"1.0" mean Line 1 , first char. Similarly END is the string end including the line break.
To remove line break at the end we have to modify like this.

t1.get("1.0",'end-1c')

Number of chars including line breaks inside a text widget

For a multi-line text above code will remove line break at the last line only. To calculate the total number of chars the user has entered inside the text widget, we have to count the number of line breaks ( excluding the last one ).
len() : Return the number of elements present in an iterable
count() : Counts the number of matching string present.

my_str=t1.get("1.0",'end-1c') # excluding the last line break char.
breaks=my_str.count('\n')  # Number of line breaks ( except last one ) 
char_numbers=len(my_str)-breaks # total chars excluding line breaks

Deleting last char inside Text widget

t1.delete('end-2c')

Counting and restricting chars in Text widget

Adding data to a text box my_str1 is the string variable to insert.

t2.insert(tk.END, my_str1)

Above codes are important to develop applications.

Note that the widely used option textvariable is not available with Text widget

There are many options we can add to text box, the list is available below.

Now let us add the click event of the button linked to text box. We will enter data in our text box , on click of the button the entered data will be displayed at another Label.

import tkinter as tk
from tkinter import BOTH, END, LEFT
my_w = tk.Tk()
my_w.geometry("500x300")  

def my_upd():
    my_str.set(t1.get("1.0",END))  # read the text box data and update the label

my_str = tk.StringVar()

l1 = tk.Label(my_w,  text='Your Name', width=10 ) # added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,  height=1, width=20,bg='yellow')# added one text box
#t1=Entry(my_w, width=10)
t1.grid(row=1,column=2) 

b1 = tk.Button(my_w, text='Update', width=10,bg='red',command=lambda: my_upd()) # button added
b1.grid(row=1,column=3) 

l2 = tk.Label(my_w,  textvariable=my_str, width=20 ) # added one Label 
l2.grid(row=1,column=4) 
my_str.set(" I will update")

my_w.mainloop()

Let us update one text box by using data from another text box.

import tkinter as tk
from tkinter import BOTH, END, LEFT
my_w = tk.Tk()
my_w.geometry("500x400")  

def my_upd():
    my_str1=t1.get("1.0",END)  # read from one text box t1
    t2.insert(tk.END, my_str1) # Add to another text box t2
    
my_str = tk.StringVar()

l1 = tk.Label(my_w,  text='Your Name', width=10 ) # added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,  height=1, width=20,bg='yellow')# added one text box
#t1=Entry(my_w, width=10)
t1.grid(row=1,column=2) 

b1 = tk.Button(my_w, text='Update', width=10,bg='red',command=lambda: my_upd()) # button added
b1.grid(row=1,column=3) 

t2 = tk.Text(my_w, height=1, width=15, bg='#00f000' ) # added one textbox to read 
t2.grid(row=1,column=4) 

my_w.mainloop()

Delete ( or empty ) text box

We can remove data from first text box after updating the second text box. In above code you can two more lines inside the function.

def my_upd():
    my_str1=t1.get("1.0",END)  # read from one text box t1
    t2.insert(tk.END, my_str1) # Add to another text box t2
    t1.delete('1.0',END)       # Delete from position 0 till end 
    t1.update()                # update the delete

Remove all inputs from all text widgets

Irrespective of number of Text boxes we used in our application, we can remove all user entered data by using winfo_children() which returns all the widget classes of the Tkinter window. Here is the code

for widget in my_w.winfo_children():
        if isinstance(widget, tk.Text):  # If this is an Entry widget 
            widget.delete(0,'end') # Delete all entries

How Reset button is used to delete all user enterd data and selections

Focus text box

To keep the ( blinking ) cursor inside text box

t1.focus()

Adding Scrollbar to Text widget

Options can be used in a textbox

Background colour of the text box

t1 = tk.Text(my_w,  width=8, height=1, bg='yellow')

We can update the background colour by using configure()

We have two radio buttons , on select of radio buttons we can change the background colour of the text box.

t1.configure(bg=r1_v.get())

Read more on Radio buttons
Full code is here

import tkinter as tk
my_w = tk.Tk()
my_w.geometry("200x200")  

l1 = tk.Label(my_w,  text='Your Name' ) # added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,  width=8, height=1)
t1.grid(row=1,column=2) 
###### Radio buttons #######
def my_upd():
    t1.configure(bg=r1_v.get()) # update the colour 

r1_v = tk.StringVar()  # We used string variable here
r1_v.set('Yellow')     # Can assign value Appear or Failed

r1 = tk.Radiobutton(my_w, text='Yellow', variable=r1_v,
 value='Yellow',command=my_upd)
r1.grid(row=2,column=1) 

r2 = tk.Radiobutton(my_w, text='Red', variable=r1_v,
 value='Red',command=my_upd)
r2.grid(row=2,column=2) 

my_w.mainloop()

bd	Border around the Text. Default width is 2 `t1 = tk.Text(my_w, width=8, height=1, bd=6)`

cursor

cursor that will appear once the mouse is over the text box

t1 = tk.Text(my_w,  width=8, height=1,cursor='circle')

You can get a list of cursor shapes in our Tkinter button page

exportselection

Selection is to be exported or not. The default is usually for widgets to export selection.

t1 = tk.Text(my_w,  width=20, height=1,
	exportselection=1)

font

Managing font size, family, type etc

t1 = tk.Text(my_w,  width=20, height=1,font=18)

font size with family

my_font=('times', 8, 'bold')
t1 = tk.Text(my_w,  width=20, height=1,font=my_font)

Zoom in & Zoom out of Text by using font size
Managing font using Menu bar

Colour used for fg

l1 = tk.Label(my_w,  text='Your Name' ) # added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,  width=10, height=1,fg='red')
t1.grid(row=1,column=2) 

t2 = tk.Text(my_w,  width=10, height=1,fg='green')
t2.grid(row=1,column=3)

height

Height in number of lines

t1 = tk.Text(my_w,  width=10, height=2)

HeighlightBackground and heightlightcolor

highlightbackground

focus highlight color ( the rectangle around the text box ) when text box is not in focus.

( Note keep highlightthickness = 2 to get a visible output of the rectangle around the text box )

t1 = tk.Text(my_w,  width=10,height=1,highlightbackground='red')

highlightcolor

focus highlight ( the rectangle around the text box ) color when text box is in focus

t1 = tk.Text(my_w,  width=10,height=1,highlightcolor='red')

highlightthickness

The width of the focus heighlight. ( the rectangle around the text box ) Default value is 1. `t1 = tk.Text(my_w, width=10,height=1,highlightthickness=2)`

insertbackground

Blinking Cursor background colour.

Here we kept insertwidth=15 to make the cursor thick enough to make it visible.

We have changed insertborderwidth=10 to make the 3 D effect visible.

t1 = tk.Text(my_w,width=10,height=1,
insertbackground='red',insertwidth=15)

insertborderwidth

Widht of the border of Cursor to give 3 D Effect.

t1 = tk.Text(my_w,width=10,height=1,
insertborderwidth=8, insertwidth=18)

insertofftime

The off time in milliseconds for the blinking cursor. For 0 value it will not blink.

t1 = tk.Text(my_w,width=10,height=1,
insertofftime=1000,insertontime=1000)

insertontime

The on time in milliseconds for the blinking cursor.

t1 = tk.Text(my_w,width=10,height=1,
insertofftime=1000,insertontime=1000)

insertwidth

Width of the blinking cursor

t1 = tk.Text(my_w,  width=10,height=1,insertwidth=15)

justify	Text justification . Values can be LEFT RIGHT or CENTER

relief The text box 3 D effect style. It can take these values
raised , sunken ,flat, ridge, solid & groove

import tkinter as tk
my_w = tk.Tk()
my_w.geometry("250x200")  
l1 = tk.Label(my_w,  text='relief' ) # added one Label 
l1.grid(row=1,column=1) 

l1 = tk.Label(my_w,  text='Raised' ) # added one Label 
l1.grid(row=2,column=1) 

t1 = tk.Text(my_w,  width=10,height=1,relief='raised')
t1.grid(row=2,column=2) 

l1 = tk.Label(my_w,  text='sunken' ) # added one Label 
l1.grid(row=3,column=1) 

t1 = tk.Text(my_w,  width=10,height=1,relief='sunken')
t1.grid(row=3,column=2)

l1 = tk.Label(my_w,  text='flat' ) # added one Label 
l1.grid(row=4,column=1) 

t1 = tk.Text(my_w,  width=10,height=1,relief='flat')
t1.grid(row=4,column=2)

l1 = tk.Label(my_w,  text='ridge' ) # added one Label 
l1.grid(row=5,column=1) 
t1 = tk.Text(my_w,  width=10,height=1,relief='ridge')
t1.grid(row=5,column=2)

l1 = tk.Label(my_w,  text='solid' ) # added one Label 
l1.grid(row=6,column=1) 
t1 = tk.Text(my_w,  width=10,height=1,relief='solid')
t1.grid(row=6,column=2)

l1 = tk.Label(my_w,  text='groove' ) # added one Label 
l1.grid(row=7,column=1) 

t1 = tk.Text(my_w,  width=10,height=1,relief='groove')
t1.grid(row=7,column=2)

my_w.mainloop()

selectbackground	The background colour of the selected text inside the textbox. `t1 = tk.Text(my_w, width=10,height=1, selectbackground='red')`
selectborderwidth	The width of the boarder around selected text
selectforeground	The colour of the font of selected text `t1 = tk.Text(my_w, width=10,height=1, selectforeground='yellow')`
width	Width in number of chars `t1 = tk.Text(my_w, height=1, width=20)`
xscrollcommand	Add scroll bar to text box
wrap	values can be char, none, word How to use Checkbutton to wrap text in Entry widget

Methods

Delete chars from start position to end position

l2.delete(1.4,1.7) # from 4th till 7th position of line one

l2.delete(1.0,END) # from starting till end

get()

print(l2.get(1.4,1.7)) # print from 4th till 7th position of line one
print(l2.get(1.0,END))  # Print from starting till end

tag_add(), tag_config() & tag_remove()

import tkinter as tk
from tkinter import BOTH, END, LEFT
my_w = tk.Tk()
my_w.geometry("400x300")  
l1 = tk.Label(my_w,text='Your Name', width=10) #added one Label 
l1.grid(row=1,column=1) 

t1 = tk.Text(my_w,width=35,height=4) #text box
t1.grid(row=1,column=2,columnspan=2,pady=30) 

font1=('Times',16,'underline')
t1.insert(tk.END, "Welcome to plus2net")

t1.tag_add("my_hg", "1.2", "1.13") # tag name my_hg is created 
t1.tag_config("my_hg",background="yellow",foreground="red",font=font1)
t1.tag_remove('my_hg','1.5','1.10') # tag is removed from part 

my_w.mainloop()

Using buttons to trigger events using tags

We can destroy the tag by using tag_delete(). Similarly we can use tag_remove() and tag_config() by using button clicks.

#t1.tag_delete('my_hg')
b1=tk.Button(my_w,text='Remove tag',command=lambda:t1.tag_remove('my_hg','1.0','1.7'))
b1.grid(row=2,column=2,pady=10)

b2=tk.Button(my_w,text='Green tag',command=lambda:t1.tag_config('my_hg',background="green",foreground="red",font=font1))
b2.grid(row=2,column=3,pady=10)

Selecting all data from Text box

def select_all(): # to select all text inside Text box 
    e1.tag_add("sel", "1.0","end") # all text selected
    e1.tag_config("sel",background="green",foreground="red")

How all text are selected for Cut copy paste in Text widgets

Tkinter text widget adding tags by usign tag_add(), tag_config(),tag_remove() and tag_delete()

Exercise on Text
Ask user to enter Name, marks ( in three subjects Physics, Chemistry, Math ) and attendance of a student. On Update , the data will be stored in a Dictionary and finally in a CSV file. ( Break it in parts, First display the data using print(), then create Dictionary and then save as CSV file. )
Create one user data entry box in the window and on click of the Save button the text entered in the entry box will be saved into one text file using the filedialog.
( Solution ) Save data entered by user in Tkinter window
Save the above user entered data to one PDF file.
( Solution ) Save data entered by user in Tkinter window to PDF file

Python Tkinter Entry How to Validate user entered data Counting and restricting chars in Text widget Tool to generate Hashtags from a string

Python Tkinter Button Python- Tutorials

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