If statement deleted by else statement in Tkinter

Question

I'm creating dictionary for myself in tkinter and when I added else statement (for any query that isn't in dictionary) it deleted first if statement (index).

I don't know exactly why. Entry (exe) works without any problems with else and index works with else deleted.

def search_button(self, event=None):
    if self.entry.get() == 'index':
        self.search_result.set("alea jacta est")

    if self.entry.get() == 'exe':
        self.search_result.set("lorem ipsum")

    else:
        self.search_result.set("Entry not in database.")

Answer 1

Your 2nd if should be elif :

def search_button(self, event=None):
    if self.entry.get() == 'index':
        self.search_result.set("alea jacta est")
    elif self.entry.get() == 'exe':
        self.search_result.set("lorem ipsum")
    else:
        self.search_result.set("Entry not in database.")

The problem with your code is that if the Entry text is 'index' then search_result is set to "alea jacta est", as expected, but then your code goes on to test if the Entry text is 'exe', which it isn't, so the search_result gets set to "Entry not in database.". You could prevent that second test by putting a return statement on the line after the self.search_result.set("alea jacta est") , but it's better to use the elif technique.

If you have a lot of possible entry texts to test, it's more efficient to use a dictionary, with the entry text as the key and the result text as the value. Here's one way to do that:

texts = {
    "index": "alea jacta est",    
    "exe": "lorem ipsum"
}

def search_button(self, event=None):
    result_text = texts.get(self.entry.get(), "Entry not in database.")
    self.search_result.set(result_text)

The dictionary technique is more efficient because dictionary lookup is fast, and relatively independent of the number of items in the dictionary.

In contrast, the if... elif...elif... technique is making a linear search over all the possible strings until it finds a match, and that can get really slow if there are a lot of items to check, although it's ok if there are only a small number of items to check. OTOH, I find the dict -based method more compact and easier to read & modify.