如何从GUIzero的文本框将字符串转换为int？

问题描述

我想从GUIzero的TextBox将字符串转换为整数。

我的项目是创建一个GUI表单，从中我将获取密码的长度和密码的数量。然后，我将显示随机密码的数量。

from guizero import App,Text,TextBox,PushButton,error
import random

# char for creating password
_chars = 'abcdefghijklmnopqrstwxyzABCDEFGHIJKLMnopQRSTUVWXYZ1234567890.,!@#$%&'

def _say_my_name():
    _welcome_message.value = "Your random value is: " + _length.value


_app = App(title="Password Creator")
message = Text(_app,text="Welcome")
_welcome_message = Text(_app,text="Create your random password here",size=19,font="Arial",color="hotpink")

#TextBox for input of password length
_length_label = Text(_app,text="Give me length of password:",size=11,font="Arial")
_length = TextBox(_app,width=33)
_length_int = int(_length.value)    #THIS DOESN'T WORK

#TextBox for input of password qty: 3 pcs/ 4pcs random password
_qty_label = Text(_app,text="How many password you want: ")
_qty_of_password = TextBox(_app,width=33)
_qty_int = int(_qty_of_password.value)  # THIS DOESN'T WORK

# I wants to run the code bellow to create a random password after I get password length and quantity of password.
#and print it to _welcome_message. this code works separetly.

for _p in range(_qty_of_password.value):
    _password = ""
    for _c in range(_length_int):
        _password += random.choice(_chars)
    print(_password)

# create a push button to transfer value of _my_name text Box to _welcome_massage
_button = PushButton(_app,command=_say_my_name,text="Click")

_app.display()

跟踪：

Traceback (most recent call last): File "C:/Users/Owner/PycharmProjects/Assignment_2/main.py",line 18,in <module> _length_int = int(_length.value) #THIS DOESN'T WORK ValueError: invalid literal for int() with base 10: ''

我从以下链接获得的主要代码：

1. https://projects.raspberrypi.org/en/projects/password-generator
2. https://projects.raspberrypi.org/en/projects/getting-started-with-guis

解决方法

您太早设置了_length_int，_qty_int。 您应该将command回调附加到文本框。

更改文本时要调用的函数的名称。该函数必须使用零或一个参数，如果该函数使用一个参数，则将返回添加到文本框中的键。

（https://lawsie.github.io/guizero/textbox/）

示例：

from guizero import App,Text,TextBox,PushButton,error
import random

# char for creating password
_chars = 'abcdefghijklmnopqrstwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890.,!@#$%&'

def _say_my_name():
    _welcome_message.value = "Your random value is: " + _length.value

_app = App(title="Password Creator")
message = Text(_app,text="Welcome")
_welcome_message = Text(_app,text="Create your random password here",size=19,font="Arial",color="hotpink")

#TextBox for input of password length
_length_label = Text(_app,text="Give me length of password:",size=11,font="Arial")
_length = TextBox(_app,width=33,command=text_box_changed)
_length_int = 0    #THIS DOESN'T WORK

#TextBox for input of password qty: 3 pcs/ 4pcs random password
_qty_label = Text(_app,text="How many password you want: ")
_qty_of_password = TextBox(_app,command=text_box_changed)
_qty_int = 0    #THIS DOESN'T WORK

# I wants to run the code bellow to create a random password after I get password length and quantity of password.
#and print it to _welcome_message. this code works separetly.

def text_box_changed():
    if not _length.value or not _qty_of_password.value:
        return

    for _p in range(int(_qty_of_password.value)):
        _password = ""
        for _c in range(int(_length.value)):
            _password += random.choice(_chars)
        print(_password)

# create a push button to transfer value of _my_name text box to _welcome_massage
_button = PushButton(_app,command=_say_my_name,text="Click")

_app.display()

,

谢谢和抱歉。我做了些吼叫。现在我有两个问题。 01.密码未显示在表单上。但是在cmd提示符下它出现了。显示屏显示“您的随机值为：[Text]对象，文本为“ None””02。我不知道要使用哪个变量来构成用于显示多个密码的数组。感谢您的宝贵时间。

ARG ENV_VAR1_DEFAULT_VALUE=VAL1
ENV_VAR1=$ENV_VAR1_DEFAULT_VALUE

,

当 Python 无法将字符串转换为整数时会出现此错误。在这种情况下，您没有在文本框中输入任何内容，因此 Python 尝试将空字符串 ("") 转换为 int，但它失败了。

您必须在代码中添加以下几行：

try:
    _length_int = int(_length.value)
except ValueError:
    print('Invalid number!')