Python-我可以使用Lambda函数通过tkinter生成重复的GUI吗？ （标签/文本/按钮）

Question

I have a very repetitive GUI to implement - think tens of label/text/button fields, for a data entry form. The sizes of each repeated section can be the same - in fact, everything can be the same except the text in the label and the variable that the data from the text field is assigned to upon completion.

I've worked with an engineer who used lambda functions to generate sub-functions in a very complex way which I almost followed, but not quite 100%. I was hoping, since this is a similar, mostly repetitive task, that there was some way to use a formulaic function to repeat the GUI creation work for me, rather than to have to type out each and every GUI item.

Is it possible to have repetitive GUI elements generated by a function, and if so, is that a lambda function? Or is there a different (or better) way to accomplish the same "not repeating myself"?

Answer 1

Is it possible to have repetitive GUI elements generated by a function, and if so, is that a lambda function?

Yes, it's possible to create gui elements with a function, and no, it's not a lambda function. Not only is it possible, it's arguably a best practice to create gui elements in a function, though you could also just use a simple loop or a conventional function.

When creating groups of widgets that are somehow tied together, it's even better to create a custom class that can encapsulate all of the behavior and provide a simple interface for the rest of the program.

Example

In the following example, we want to create a series of widgets with a label, an entry, and a submit button. It is going to be implemented as a class, since we are in effect creating an object that represents one form field.

Note: the following code assumes you imported tkinter with import tkinter as tk .

First, lets create a callback that sets a value in a dictionary, and also prints out the value for debugging purposes. The callback will be given the name of the field, and the value that the user entered:

data = {}
def handle_submit(name, value):
    print("you submitted '%s' for %s" % (value, name))
    data[name] = value

Next, the code to create 10 items would might look like this:

root = tk.Tk()
for i in range(1, 11):
    field_name = "field %s" % i
    row = CustomWidget(root, name=field_name, callback=handle_submit)

Finally, we need to create our class. We inherit from tk.Frame so that we can use it like any other tkinter widget. It needs to take parameters for its parent, the field name, and the function to call when the user presses submit:

class CustomWidget(tk.Frame):
    def __init__(self, parent, name, callback):
        tk.Frame.__init__(self, parent)

        self.name = name
        label_text = name.title() + ":"
        self.callback = callback
        self.label = tk.Label(self, text=label_text, anchor="e")
        self.entry = tk.Entry(self)
        self.button = tk.Button(self, text="Submit", command=self.submit)

        self.button.pack(side="right")
        self.label.pack(side="left")
        self.entry.pack(side="left", fill="x", expand=True)

    def submit(self):
        self.callback(self.name, self.entry.get())