python - tkinter 中的 for 循环问题

Question

所以我正在做一个小项目，我试图从用户那里获得输入使用条目小部件，然后比较并查看输入中的任何单词是否与列表中的一个或多个单词匹配，由于某种原因它起作用并且程序发送读取并尝试匹配并且 instad 直接跳转到显示标签，只有当其中一个词匹配时它才应该打印:

e = Entry(window, width=40, borderwidth=3, font='Arial 20')
e.place(rely=0.2, relx=0.24)
r1 = Label(window, text="good", font='Arial 20')

def s_command():
    x = ["egg","milk","rice","salt"]
    s_input = e.get().split(" ")
    for s_input in x:
        r1.pack()

S_button = Button(window, text="Search", font='Arial 22', width=8, command=s_command)
S_button.place(rely=0.25, relx=0.4)

Answer 1

这里的一种方法是，您可以使用嵌套循环，因为您需要检查用户是否输入了多个项目以及列表中是否存在任何项目。

def s_command():
    x = ["egg","milk","rice","salt"]
    s_input = e.get().split(" ")

    for inp in s_input: # Go through input list
        for item in x: # Go through items list
            if inp == item: # If an input is same as item
                r1.pack() # Show the widget
                break # Stop the loop because you want to check if any item matches
            else: 
                r1.pack_forget() # Remove the label
        # Make the nested loop break the outer loop
        else:
            continue
        break

下一个方法是只使用一个循环(如 JRiggles 的回答中所示)，如果该项目存在于使用 in 的列表中，例如:

def s_command():
    x = ["egg", "milk", "rice", "salt"]
    s_input = e.get().split(' ')
    
    for inp in s_input:
        if inp in x:
            r1.pack()
            break
        else:
            r1.pack_forget()

如果您只需要检查列表中的一项，那么它会容易得多:

def s_command():
    x = ["egg", "milk", "rice", "salt"]
    s_input = e.get() # Only single item so no need to split
    
    if s_input in x:
        r1.pack()
    else:
        r1.pack_forget()