Hướng dẫn tkinter python 3

Thêm một tiện ích

Bây giờ bạn đã có một cửa sổ, bạn có thể thêm tiện ích. Sử dụng lớp

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

Cửa sổ bạn đã tạo trước đó không thay đổi. Bạn vừa tạo một tiện ích

>>> import tkinter as tk

>>>

>>> import tkinter as tk

Cửa sổ bây giờ trông như thế này

Khi bạn đóng gói một tiện ích vào một cửa sổ, Tkinter sẽ điều chỉnh kích thước cửa sổ nhỏ nhất có thể trong khi vẫn bao gồm đầy đủ tiện ích. Bây giờ thực hiện như sau

>>>

>>> import tkinter as tk

Dường như không có gì xảy ra, nhưng lưu ý rằng không có lời nhắc mới nào xuất hiện trong trình bao

>>> import tkinter as tk

Cảnh báo. Khi bạn làm việc với Tkinter từ REPL của Python, các bản cập nhật cho cửa sổ được áp dụng khi mỗi dòng được thực thi. Đây không phải là trường hợp khi chương trình Tkinter được thực thi từ tệp Python

Nếu bạn không bao gồm

>>> import tkinter as tk

>>> import tkinter as tk

Tạo một cửa sổ với Tkinter chỉ mất một vài dòng mã. Nhưng các cửa sổ trống không hữu ích lắm. Trong phần tiếp theo, bạn sẽ tìm hiểu về một số tiện ích có sẵn trong Tkinter và cách bạn có thể tùy chỉnh chúng để đáp ứng nhu cầu của ứng dụng của mình

Kiểm tra việc hiểu của bạn

Mở rộng các khối mã bên dưới để kiểm tra sự hiểu biết của bạn

Tập thể dục. Tạo cửa sổ TkinterHiển thị/Ẩn

Viết một tập lệnh Python đầy đủ để tạo cửa sổ Tkinter với văn bản

>>> import tkinter as tk

Cửa sổ sẽ trông như thế này

Hãy thử bài tập này ngay bây giờ

Bạn có thể mở rộng khối mã bên dưới để xem giải pháp

Giải pháp. Tạo cửa sổ TkinterHiển thị/Ẩn

Đây là một giải pháp khả thi

>>> import tkinter as tk

Hãy nhớ rằng mã của bạn có thể trông khác

Khi bạn đã sẵn sàng, bạn có thể chuyển sang phần tiếp theo

Hiển thị văn bản và hình ảnh với các widget

>>> import tkinter as tk

05

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Bạn có thể kiểm soát văn bản và màu nền của

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Có rất nhiều tên màu hợp lệ, bao gồm

• >>> import tkinter as tk
  

  39

• >>> import tkinter as tk
  

  40

• >>> import tkinter as tk
  

  41

• >>> import tkinter as tk
  

  42

• >>> import tkinter as tk
  

  43

• >>> import tkinter as tk
  

  44

Nhiều tên màu HTML hoạt động với Tkinter. Để tham khảo đầy đủ, bao gồm các màu hệ thống dành riêng cho macOS và Windows mà chủ đề hệ thống hiện tại kiểm soát, hãy xem trang hướng dẫn sử dụng màu

Bạn cũng có thể chỉ định màu bằng các giá trị RGB thập lục phân

>>> import tkinter as tk

Thao tác này đặt nền nhãn thành màu xanh lam nhạt đẹp mắt. Các giá trị RGB thập lục phân khó hiểu hơn các màu được đặt tên, nhưng chúng cũng linh hoạt hơn. May mắn thay, có những công cụ giúp việc lấy mã màu thập lục phân tương đối dễ dàng

Nếu bạn không muốn gõ

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Bạn cũng có thể kiểm soát chiều rộng và chiều cao của nhãn bằng tham số

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Đây là những gì nhãn này trông giống như trong một cửa sổ

It may seem strange that the label in the window isn’t square even though the width and height are both set to

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Note. For width and height measurements, Tkinter uses text units, instead of something like inches, centimeters, or pixels, to ensure consistent behavior of the application across platforms

Measuring units by the width of a character means that the size of a widget is relative to the default font on a user’s machine. This ensures the text fits properly in labels and buttons, no matter where the application is running

Labels are great for displaying some text, but they don’t help you get input from a user. The next three widgets that you’ll learn about are all used to get user input

Displaying Clickable Buttons With

>>> import tkinter as tk

16 Widgets

>>> import tkinter as tk

There are many similarities between

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Here’s what the button looks like in a window

Pretty nifty. You can use the next two widgets to collect text input from a user

Getting User Input With

>>> import tkinter as tk

17 Widgets

When you need to get a little bit of text from a user, like a name or an email address, use an

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Tuy nhiên, điều thú vị về các widget của

>>> import tkinter as tk

>>> import tkinter as tk

1. Truy xuất văn bản bằng

   >>> import tkinter as tk
   

   70
2. Xóa văn bản bằng

   >>> import tkinter as tk
   

   71
3. Chèn văn bản với

   >>> import tkinter as tk
   

   72

Cách tốt nhất để hiểu về các vật dụng của

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> import tkinter as tk

Bây giờ hãy tạo tiện ích con

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> import tkinter as tk

Đây là những gì trông giống như

Lưu ý rằng Tkinter tự động căn giữa nhãn phía trên tiện ích con

>>> import tkinter as tk

>>> import tkinter as tk

Nhấp vào bên trong tiện ích

>>> import tkinter as tk

>>> import tkinter as tk

Bây giờ bạn đã nhập một số văn bản vào tiện ích

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Bạn cũng có thể xóa văn bản. Phương thức

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Văn bản còn lại trong widget bây giờ là

>>> import tkinter as tk

Lưu ý rằng, giống như đối tượng chuỗi Python, văn bản trong tiện ích con

>>> import tkinter as tk

>>> import tkinter as tk

Nếu bạn cần xóa một số ký tự khỏi

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Văn bản còn lại bây giờ là

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Bây giờ bạn sẽ thấy một hộp văn bản trống

Ngược lại, bạn cũng có thể chèn văn bản vào tiện ích

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Cửa sổ bây giờ trông như thế này

Đối số đầu tiên cho biết vị trí chèn văn bản của

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> import tkinter as tk

Nếu

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

Văn bản tiện ích hiện có nội dung là

>>> import tkinter as tk

Các tiện ích

>>> import tkinter as tk

>>> import tkinter as tk

Nhận đầu vào của người dùng nhiều dòng với các widget

>>> import tkinter as tk

18

Tiện ích

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

1. Retrieve text with

   >>> import tkinter as tk
   

   70
2. Delete text with

   >>> import tkinter as tk
   

   71
3. Insert text with

   >>> import tkinter as tk
   

   72

Although the method names are the same as the

>>> import tkinter as tk

>>> import tkinter as tk

Note. Do you still have the window from the previous section open?

If so, then you can close it by executing the following

>>>

>>> window = tk.Tk[]

You can also close it manually by clicking the Close button

In your Python shell, create a new blank window and pack a

>>> window = tk.Tk[]

>>>

>>> window = tk.Tk[]

Text boxes are much larger than

>>> import tkinter as tk

Click anywhere inside the window to activate the text box. Type in the word

>>> window = tk.Tk[]

>>> window = tk.Tk[]

Just like with

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

1. The line number of a character
2. The position of a character on that line

Line numbers start with

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

Use the index

>>> window = tk.Tk[]

>>>

>>> window = tk.Tk[]

There are five letters in the word

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> window = tk.Tk[]

So, to get the word

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

To get the word

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

To get all of the text in a text box, set the starting index in

>>> window = tk.Tk[]

>>> import tkinter as tk

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

Notice that text returned by

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

1. With a single argument
2. With two arguments

Using the single-argument version, you pass to

>>> import tkinter as tk

>>> window = tk.Tk[]

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

The first line of text in the window now reads

>>> window = tk.Tk[]

Với phiên bản hai đối số, bạn chuyển hai chỉ mục để xóa một dải ký tự bắt đầu từ chỉ mục đầu tiên và tối đa nhưng không bao gồm chỉ mục thứ hai

For example, to delete the remaining

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

Notice that the text is gone from the first line. This leaves a blank line followed the word

>>> window = tk.Tk[]

Even though you can’t see it, there’s still a character on the first line. It’s a newline character. You can verify this using

>>> import tkinter as tk

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

If you delete that character, then the rest of the contents of the text box will shift up a line

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

Now,

>>> window = tk.Tk[]

Try to clear out the rest of the text in the text box. Set

>>> window = tk.Tk[]

>>> import tkinter as tk

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

The text box is now empty

You can insert text into a text box using

>>> import tkinter as tk

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

This inserts the word

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> import tkinter as tk

Check out what happens if you try to insert the word

>>> window = tk.Tk[]

>>>

>>> greeting = tk.Label[text="Hello, Tkinter"]

Instead of inserting the text on the second line, the text is inserted at the end of the first line

If you want to insert text onto a new line, then you need to insert a newline character manually into the string being inserted

>>>

>>> import tkinter as tk

Now

>>> window = tk.Tk[]

>>> import tkinter as tk

1. Insert text at the specified position if there’s already text at or after that position
2. Append text to the specified line if the character number is greater than the index of the last character in the text box

It’s usually impractical to try and keep track of what the index of the last character is. The best way to insert text at the end of a

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>>

>>> import tkinter as tk

Don’t forget to include the newline character [

>>> window = tk.Tk[]

>>>

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Assigning Widgets to Frames With

>>> import tkinter as tk

19 Widgets

In this tutorial, you’re going to work with only five widgets

1. >>> import tkinter as tk
   

   05

2. >>> import tkinter as tk
   

   16

3. >>> import tkinter as tk
   

   17

4. >>> import tkinter as tk
   

   18

5. >>> import tkinter as tk
   

   19

These are the four you’ve seen so far plus the

>>> import tkinter as tk

>>> import tkinter as tk

Before you get into the details about laying out the visual presentation of your widgets, take a closer look at how

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

An empty

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

To get a feel for how this works, write a script that creates two

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

Note that

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

Now see what happens when you swap the order of

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

The output looks like this

Now

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

All four of the widget types that you’ve learned about—

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

Note. If you omit the

>>> greeting = tk.Label[text="Hello, Tkinter"]

In addition to grouping your widgets logically,

>>> import tkinter as tk

>>> import tkinter as tk

Adjusting Frame Appearance With Reliefs

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  35. Has no border effect [the default value]

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  36. Creates a sunken effect

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  37. Creates a raised effect

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  38. Creates a grooved border effect

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  39. Tạo hiệu ứng gợn sóng

To apply the border effect, you must set the

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

Here’s a breakdown of this script

• Lines 3 to 9 create a dictionary whose keys are the names of the different relief effects available in Tkinter. The values are the corresponding Tkinter objects. This dictionary is assigned to the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  44 variable

• Line 13 starts a

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  45 loop to loop over each item in the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  44 dictionary

• Line 14 creates a new

  >>> import tkinter as tk
  

  19 widget and assigns it to the

  >>> import tkinter as tk
  

  03 object. The

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  33 attribute is set to the corresponding relief in the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  44 dictionary, and the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  51 attribute is set to

  >>> import tkinter as tk
  

  61 so that the effect is visible

• Line 15 packs the

  >>> import tkinter as tk
  

  19 into the window using

  >>> import tkinter as tk
  

  10. The

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  55 keyword argument tells Tkinter in which direction to pack the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  56 objects. You’ll see more about how this works in the next section

• Lines 16 and 17 create a

  >>> import tkinter as tk
  

  05 widget to display the name of the relief and pack it into the

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  56 object you just created

The window produced by the above script looks like this

In this image, you can see the following effects

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  35 creates a frame that appears to be flat

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  36 adds a border that gives the frame the appearance of being sunken into the window

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  37 gives the frame a border that makes it appear to stick out from the screen

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  38 adds a border that appears as a sunken groove around an otherwise flat frame

• >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  39 gives the appearance of a raised lip around the edge of the frame

These effects give your Python GUI Tkinter application a bit of visual appeal

Understanding Widget Naming Conventions

When you create a widget, you can give it any name you like, as long as it’s a valid Python identifier. It’s usually a good idea to include the name of the widget class in the variable name that you assign to the widget instance. For example, if a

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

Note. Sometimes, you may define a new widget without assigning it to a variable. You’ll call its

>>> import tkinter as tk

>>>

>>> import tkinter as tk

This might be helpful when you don’t intend to refer to the widget’s instance later on. Due to automatic memory management, Python would normally garbage collect such unassigned objects, but Tkinter prevents that by registering every new widget internally

When you include the widget class name in the variable name, you help yourself and anyone else who needs to read your code to understand what type of widget the variable name refers to. However, using the full name of the widget class can lead to long variable names, so you may want to adopt a shorthand for referring to each widget type. For the rest of this tutorial, you’ll use the following shorthand prefixes to name widgets

Widget ClassVariable Name PrefixExample

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

In this section, you learned how to create a window, use widgets, and work with frames. At this point, you can make some plain windows that display messages, but you’ve yet to create a full-blown application. In the next section, you’ll learn how to control the layout of your applications using Tkinter’s powerful geometry managers

Kiểm tra việc hiểu của bạn

Expand the code block below for an exercise to check your understanding

Exercise. Create an Entry widget and insert some textShow/Hide

Write a complete script that displays an

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

The output window should look like this

Hãy thử bài tập này ngay bây giờ

Bạn có thể mở rộng khối mã bên dưới để xem giải pháp

Solution. Create an Entry widget and insert some textShow/Hide

There are a couple of ways to solve this exercise. Here’s one solution that uses the

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

This solution is great because it explicitly sets the background and foreground colors for the

>>> import tkinter as tk

On most systems, the default background color for an

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Hãy nhớ rằng mã của bạn có thể trông khác

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The

>>> import tkinter as tk

10 Geometry Manager

The

>>> import tkinter as tk

>>> import tkinter as tk

1. Compute a rectangular area called a parcel that’s just tall [or wide] enough to hold the widget and fills the remaining width [or height] in the window with blank space
2. Center the widget in the parcel unless a different location is specified

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Each

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

There are three invisible parcels, each containing one of the three

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Notice that the

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

The window produced by this script looks like this

One of the nice things about filling the window with

>>> import tkinter as tk

>>> import tkinter as tk

Notice, though, that the

>>> import tkinter as tk

The

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

• >>> import tkinter as tk
  

  334

• >>> import tkinter as tk
  

  335

• >>> import tkinter as tk
  

  336

• >>> import tkinter as tk
  

  337

If you don’t set

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

This time, you have to specify the

>>> import tkinter as tk

The resulting window looks like this

Just like when you set

>>> import tkinter as tk

>>> import tkinter as tk

To make the layout truly responsive, you can set an initial size for your frames using the

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

When you run the above script, you’ll see a window that initially looks the same as the one you generated in the previous example. The difference is that now you can resize the window however you want, and the frames will expand and fill the window responsively

Pretty cool

The

>>> greeting = tk.Label[text="Hello, Tkinter"]

97 Geometry Manager

You can use

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Keep in mind that the origin, where

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

Here’s an example of how the

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

Here’s how this code works

• Lines 5 and 6 create a new

  >>> import tkinter as tk
  

  19 widget called

  >>> greeting = tk.Label[text="Hello, Tkinter"]
  

  56, measuring

  >>> import tkinter as tk
  

  368 pixels wide and

  >>> import tkinter as tk
  

  368 pixels tall, and pack it into the window with

  >>> import tkinter as tk
  

  10
• Lines 8 and 9 create a new

  >>> import tkinter as tk
  

  05 called

  >>> import tkinter as tk
  

  372 with a red background and place it in

  >>> import tkinter as tk
  

  373 at position [0, 0]
• Lines 11 and 12 create a second

  >>> import tkinter as tk
  

  05 called

  >>> import tkinter as tk
  

  375 with a yellow background and place it in

  >>> import tkinter as tk
  

  373 at position [75, 75]

Here’s the window that the code produces

Note that if you run this code on a different operating system that uses different font sizes and styles, then the second label might become partially obscured by the window’s edge. That’s why

>>> greeting = tk.Label[text="Hello, Tkinter"]

1. Layout can be difficult to manage with

   >>> greeting = tk.Label[text="Hello, Tkinter"]
   

   97. This is especially true if your application has lots of widgets
2. Layouts created with

   >>> greeting = tk.Label[text="Hello, Tkinter"]
   

   97 aren’t responsive. They don’t change as the window is resized

One of the main challenges of cross-platform GUI development is making layouts that look good no matter which platform they’re viewed on, and

>>> greeting = tk.Label[text="Hello, Tkinter"]

That’s not to say you should never use

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

The

>>> greeting = tk.Label[text="Hello, Tkinter"]

98 Geometry Manager

The geometry manager you’ll likely use most often is

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> greeting = tk.Label[text="Hello, Tkinter"]

The following script creates a 3 × 3 grid of frames with

>>> import tkinter as tk

>>> import tkinter as tk

Here’s what the resulting window looks like

You’re using two geometry managers in this example. Each frame is attached to

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

Each

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

The important thing to realize here is that even though

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

The frames in the previous example are placed tightly next to one another. To add some space around each frame, you can set the padding of each cell in the grid. Padding is just some blank space that surrounds a widget and visually sets its content apart

The two types of padding are external and internal padding. External padding adds some space around the outside of a grid cell. It’s controlled with two keyword arguments to

>>> greeting = tk.Label[text="Hello, Tkinter"]

1. >>> import tkinter as tk
   

   412 adds padding in the horizontal direction

2. >>> import tkinter as tk
   

   413 adds padding in the vertical direction

Both

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Here’s the resulting window

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

The extra padding around the

>>> import tkinter as tk

>>> import tkinter as tk

Điều đó trông khá đẹp. But if you try and expand the window in any direction, then you’ll notice that the layout isn’t very responsive

The whole grid stays at the top-left corner as the window expands

By using

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

1. Index. The index of the grid column or row that you want to configure or a list of indices to configure multiple rows or columns at the same time
2. Weight. A keyword argument called

   >>> import tkinter as tk
   

   431 that determines how the column or row should respond to window resizing, relative to the other columns and rows
3. Minimum Size. A keyword argument called

   >>> import tkinter as tk
   

   432 that sets the minimum size of the row height or column width in pixels

>>> import tkinter as tk

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

On each iteration of the loop, the

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

The result is a grid layout that expands and contracts smoothly as the window is resized

Try it yourself to get a feel for how it works. Play around with the

>>> import tkinter as tk

>>> import tkinter as tk

By default, widgets are centered in their grid cells. For example, the following code creates two

>>> import tkinter as tk

>>> import tkinter as tk

Each grid cell is

>>> import tkinter as tk

>>> window = tk.Tk[]

You can change the location of each label inside of the grid cell using the

>>> import tkinter as tk

• >>> import tkinter as tk
  

  454 or

  >>> import tkinter as tk
  

  455 to align to the top-center part of the cell

• >>> import tkinter as tk
  

  456 or

  >>> import tkinter as tk
  

  457 to align to the right-center side of the cell

• >>> import tkinter as tk
  

  458 or

  >>> import tkinter as tk
  

  459 to align to the bottom-center part of the cell

• >>> import tkinter as tk
  

  460 or

  >>> import tkinter as tk
  

  461 to align to the left-center side of the cell

The letters

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Here’s the output

You can combine multiple letters in a single string to position each label in the corner of its grid cell

>>> import tkinter as tk

In this example, the

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

When a widget is positioned with

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Here’s what the output looks like

What the above example illustrates is that the

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> import tkinter as tk

>>> greeting = tk.Label[text="Hello, Tkinter"]

>>> greeting = tk.Label[text="Hello, Tkinter"]

Note.

>>> greeting = tk.Label[text="Hello, Tkinter"]

Now that you’ve got the fundamentals of geometry managers down for the Python GUI framework Tkinter, the next step is to assign actions to buttons to bring your applications to life

Kiểm tra việc hiểu của bạn

Expand the code block below for an exercise to check your understanding

Exercise. Create an address entry formShow/Hide

Below is an image of an address entry form made with Tkinter

Write a complete script that re-creates the window. You may use any geometry manager you like

Bạn có thể mở rộng khối mã bên dưới để xem giải pháp

Solution. Create an address entry formShow/Hide

There are many different ways to solve this exercise. If your solution generates a window identical to the one in the exercise statement, then congratulations. You’ve successfully solved the exercise. Below, you can look at two solutions that use the

>>> greeting = tk.Label[text="Hello, Tkinter"]

One solution creates a

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

There’s nothing wrong with this solution. It’s a bit long, but everything is very explicit. If you want to change something, then it’s clear to see exactly where to do so

That said, the solution can be considerably shortened by recognizing that each

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

In this solution, a list is used to store the strings for each label in the form. They’re stored in the order that each form field should appear. Then,

>>> import tkinter as tk

>>> import tkinter as tk

Khi bạn đã sẵn sàng, bạn có thể chuyển sang phần tiếp theo

Using Events and Event Handlers

When you create a Tkinter application, you must call

>>> import tkinter as tk

The event loop is provided for you with Tkinter, so you don’t have to write any code that checks for events yourself. However, you do have to write the code that will be executed in response to an event. In Tkinter, you write functions called event handlers for the events that you use in your application

Note. An event is any action that occurs during the event loop that might trigger some behavior in the application, such as when a key or mouse button is pressed

When an event occurs, an event object is emitted, which means that an instance of a class representing the event is created. You don’t need to worry about instantiating these classes yourself. Tkinter will create instances of event classes for you automatically

You’ll write your own event loop in order to better understand how Tkinter’s event loop works. That way, you can see how Tkinter’s event loop fits into your application, and which parts you need to write yourself

Assume there’s a list called

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Right now, the event loop that you’ve created doesn’t do anything with

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Assume that

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

When you call

>>> import tkinter as tk

1. It maintains a list of events that have occurred
2. It runs an event handler any time a new event is added to that list

Update your event loop to use

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Using

>>> import tkinter as tk

921

To call an event handler whenever an event occurs on a widget, use

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Ở đây, trình xử lý sự kiện

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Note. The output of the above program is not printed in the Tkinter application window. It’s printed to the standard output stream [stdout]

If you run the program in IDLE, then you’ll see the output in the interactive window. If you run the program from a terminal, then you should see the output in your terminal

>>> import tkinter as tk

1. An event that’s represented by a string of the form

   >>> import tkinter as tk
   

   930, where

   >>> import tkinter as tk
   

   931 can be any of Tkinter’s events
2. An event handler that’s the name of the function to be called whenever the event occurs

The event handler is bound to the widget on which

>>> import tkinter as tk

In the example above, the event handler is bound to the window itself, but you can bind an event handler to any widget in your application. For example, you can bind an event handler to a

>>> import tkinter as tk

>>> import tkinter as tk

In this example, the

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Note. For a list of commonly used events, see the Event types section of the Tkinter 8. 5 reference

You can bind any event handler to any kind of widget with

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Using

>>> import tkinter as tk

942

Every

>>> import tkinter as tk

>>> import tkinter as tk

Take a look at an example. First, you’ll create a window with a

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Cửa sổ trông như thế này

With the app layout defined, you can bring it to life by giving the buttons some commands. Start with the left button. When this button is pressed, it should decrease the value in the label by one. In order to do this, you first need to get answers to two questions

1. How do you get the text in

   >>> import tkinter as tk
   

   05?
2. How do you update the text in

   >>> import tkinter as tk
   

   05?

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Now that you know how to get and set a label’s text, write an

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

You’ll also need

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

Put

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

To connect the buttons to the functions, assign the function to the button’s

>>> import tkinter as tk

>>> import tkinter as tk

That’s all you need to do to bind the buttons to

>>> import tkinter as tk

>>> import tkinter as tk

Here’s the full application code for your reference

Counter Application Full Source CodeShow/Hide

>>> import tkinter as tk

This app isn’t particularly useful, but the skills you learned here apply to every app you’ll make

• Use widgets to create the components of the user interface
• Use geometry managers to control the layout of the application
• Write event handlers that interact with various components to capture and transform user input

In the next two sections, you’ll build more useful apps. First, you’ll build a temperature converter that converts a temperature value from Fahrenheit to Celsius. After that, you’ll build a text editor that can open, edit, and save text files

Kiểm tra việc hiểu của bạn

Expand the code block below for an exercise to check your understanding

Exercise. Simulate rolling a six-sided dieShow/Hide

Write a program that simulates rolling a six-sided die. There should be one button with the text

>>> import tkinter as tk

>>> window = tk.Tk[]

>>> import tkinter as tk

Hint. You can generate a random number using

>>> import tkinter as tk

>>> import tkinter as tk

>>> import tkinter as tk

The application window should look something like this

Hãy thử bài tập này ngay bây giờ

Bạn có thể mở rộng khối mã bên dưới để xem giải pháp

Solution. Simulate rolling a six-sided dieShow/Hide

Đây là một giải pháp khả thi

>>> import tkinter as tk

Keep in mind that your code may look different

Khi bạn đã sẵn sàng, bạn có thể chuyển sang phần tiếp theo