如何在Python中将字符串列表转换为整数？

Question

I'm using a combobox in Python tkinter to represent the user of the program with a few readable options. These options need to be converted to integers later in the code. How do I do this efficiently?

An example for my Combobox:

example1 = Combobox(values=['Engine', 'Network', ...]

What I am using now to convert each String value in the Combobox is a bulky If...Else construction like so:

config = example1.get()

if config == 'Engine':
    config = 0
elif config == 'Network':
    config = 1
...

I feel like this is an efficient yet sloppy way of coding.

I've tried something to do with enum but I can't figure out how to do it.

Any suggestions?

EDIT: For this specific example I do in fact need the index of the combobox. But what if the Combobox contains Strings that are not based on the index, for example:

...
example2 = Combobox(values=['Global', 'Action', 'Audio', 'Info']

config = example2.get()

if config == 'Global' or config == 'Action':
    config = 0
elif config = 'Audio':
    config = 1:
elif config == 'Info':
    config = 2
...

Answer 1

You can use a dictionnary

d = {"Engine" : 0, "Network" : 1 }
config = "Engine"
config = d.get(config) # config is now equal to 0

Answer 2

You can use method index of list to replace if-elif block following way:

options = ['Engine', 'Network']
config = 'Network'
config = options.index(config)
print(config) # 1

options should be same list, as that one you deliver to values of Combobox . index return lowest index of given element inside list - in my example 1 , because options[1] is 'Network' .

Answer 3

You could use config_idx = values.index(config) to get numeric config values for any entry in the values list. This is more pythonic and concise.

Solution to Example-1

values = ['Engine', 'Network', 'Car', 'Bus', 'Train', 'Horse']
test_config = [values[x] for x in [0,2,4]]

#config = 'Network'

for config in test_config:
    print('{}: {}'.format(config, values.index(config)))

Output

Engine: 0
Car: 2
Train: 4

Solution to Example-2

Here the solution would be to define a list of rule groups, which is a list of lists. Each list represents a group of config values that you want to assign the same config id.

# Define a list of rule groups: a list of lists. 
#     Each list represents a group of 
#     config values to be identified 
#     by the same integer.
rule_groups = [['Engine', 'Network'], ['Car'], ['Bus'], ['Train'], ['Horse']]

# Get config ids
for config in values:
    for rule_group in rule_groups:
        if config in rule_group:
            print('{}: {}'.format(config, rules_group.index(rule_group)))

Output

Engine: 0
Network: 0
Car: 1
Bus: 2
Train: 3
Horse: 4

Supplementary Code

You could also specify the rule_groups as follows and let the code restructure them properly to make it a list of lists. So, you only put those config values into a list that are grouped together. For the rest, you could just copy-paste from the values list. This will help managing your code if you have a lot of config values, which may or may not increase/decrease over time based on future requirements.

rule_groups = [['Engine', 'Network'], 'Car', 'Bus', 'Train', 'Horse']

for i, rule_group in enumerate(rule_groups):
    if not isinstance(rule_group,list):
        rule_groups[i] = [rule_group,]

rule_groups

Output

[['Engine', 'Network'], ['Car'], ['Bus'], ['Train'], ['Horse']]

Answer 4

If you respect the order of your combo values you can use .current() method of the

combo remember that it count from 0, as this script show.

Select an item from the combobox and see what happend.

 #!/usr/bin/python3
import tkinter as tk
from tkinter import ttk
from tkinter import messagebox

class App(tk.Tk):
    """Docstring about this class"""

    def __init__(self):
        super().__init__()

        self.protocol("WM_DELETE_WINDOW", self.on_exit)
        s = "{0}".format('Simple App')
        self.title(s)

        self.values = ('Engine', 'Network','Apple','Banana','Orange','Grapes','Watermelon','Plum','Strawberries','Pear')

        self.selected_data = tk.StringVar()


        self.init_ui()

    def init_ui(self):

        f = ttk.Frame()

        ttk.Label(f, text = "Combobox").pack()
        self.cbCombo = ttk.Combobox(f,state='readonly',values=self.values)
        self.cbCombo.bind("<<ComboboxSelected>>", self.on_selected)
        self.cbCombo.pack()

        ttk.Label(f, textvariable = self.selected_data).pack()

        w = ttk.Frame()

        ttk.Button(w, text="Callback", command=self.on_callback).pack()
        ttk.Button(w, text="Reset", command=self.on_reset).pack()
        ttk.Button(w, text="Exit", command=self.on_exit).pack()

        f.pack(side=tk.LEFT, fill=tk.BOTH, expand=1)
        w.pack(side=tk.RIGHT, fill=tk.BOTH, expand=1)


    def on_selected(self, evt=None):

         if self.cbCombo.current() != -1:

              msg = "You have selected:\n{0} {1}".format(self.cbCombo.current(), self.cbCombo.get())

              self.selected_data.set(msg)

    def on_callback(self,):

        if self.cbCombo.current() != -1:

            msg = "You have selected:\n{0} {1}".format(self.cbCombo.current(), self.cbCombo.get())
        else:
            msg = "You did not select anything"

        messagebox.showinfo(self.title(), msg)

    def on_reset(self):
        self.cbCombo.set('')


    def on_exit(self):
        """Close all"""
        if messagebox.askokcancel(self.title(), "Do you want to quit?", parent=self):
            self.destroy()               

if __name__ == '__main__':
    app = App()
    app.mainloop()

Answer 5

You can make use of the <<ComboboxSelected>> event to know what item has been selected.

Alternatively, use combobox::current to get the index of the currently selected item, and combobox::get to get the value