Python 从函数到类内函数的函数调用失败
我正在尝试设置一个程序，其中tkinter GUI函数位于一个类中，而数据库函数位于另一个类中。我在两个类之外都有一个函数，当我试图调用DB类中的函数时，该函数会失败。你能帮我解决这个错误吗？我的GUI和任何数据库是否都应该处于单独的功能中，或者这是一个糟糕的设计。附加的代码是一个精简版本，以说明我的问题。单击“全部查看”按钮将生成错误Python 从函数到类内函数的函数调用失败,python,class,tkinter,Python,Class,Tkinter,我正在尝试设置一个程序，其中tkinter GUI函数位于一个类中，而数据库函数位于另一个类中。我在两个类之外都有一个函数，当我试图调用DB类中的函数时，该函数会失败。你能帮我解决这个错误吗？我的GUI和任何数据库是否都应该处于单独的功能中，或者这是一个糟糕的设计。附加的代码是一个精简版本，以说明我的问题。单击“全部查看”按钮将生成错误 import sqlite3 from tkinter import * from tkinter import messagebox class DB:
import sqlite3
from tkinter import *
from tkinter import messagebox
class DB:
def __init__(self):
self.conn = sqlite3.connect("mybooks.db")
self.cur = self.conn.cursor()
self.cur.execute(
"CREATE TABLE IF NOT EXISTS book (id INTEGER PRIMARY KEY, title TEXT, author TEXT, isbn INTEGER)")
self.conn.commit()
def __del__(self):
self.conn.close()
def view(self):
self.cur.execute("SELECT * FROM book")
rows = cur.fetchall()
return rows
def view_command():
# there is a problem with the next line
# when rows=DB.view() error is TypeError: view() missing 1 required positional argument: 'self'
# when rows=DB.view(self) error is NameError: name 'self' is not defined
rows=DB.view(self)
for row in rows:
print(row)
class App_GUI(): # create the main window
def __init__(self, master):
self.master = master
self.master.title("My Books")
self.master.l1 = Label(self.master, text="Title")
self.master.l1.grid(row=0, column=0)
self.master.l2 = Label(self.master, text="Author")
self.master.l2.grid(row=0, column=2)
self.master.l3 = Label(self.master, text="ISBN")
self.master.l3.grid(row=1, column=0)
self.master.title_text = StringVar()
self.master.e1 = Entry(self.master, textvariable=self.master.title_text)
self.master.e1.grid(row=0, column=1)
self.master.author_text = StringVar()
self.master.e2 = Entry(self.master, textvariable=self.master.author_text)
self.master.e2.grid(row=0, column=3)
self.master.isbn_text = StringVar()
self.master.e3 = Entry(self.master, textvariable=self.master.isbn_text)
self.master.e3.grid(row=1, column=1)
self.master.list1 = Listbox(self.master, height=6, width=35)
self.master.list1.grid(row=2, column=0, rowspan=6, columnspan=2)
self.master.sb1 = Scrollbar(self.master)
self.master.sb1.grid(row=2, column=2, rowspan=6)
self.master.list1.configure(yscrollcommand=self.master.sb1.set)
self.master.sb1.configure(command=self.master.list1.yview)
self.master.b1 = Button(self.master, text="View all", width=12, command=view_command)
self.master.b1.grid(row=2, column=3)
self.master.b6 = Button(self.master, text="Close", width=12, command=self.master.destroy)
self.master.b6.grid(row=7, column=3)
return
###############################
# Program Main #
###############################
def main():
db = DB()
root = Tk()
def on_closing():
dd = db
if messagebox.askokcancel("Quit", "Do you want to close the application"): # ask the user if he/she wants to close the application
root.destroy()
del dd
root.protocol("WM_DELETE_WINDOW", on_closing) # catch the user closing the window
app = App_GUI(root) # creation of an instance
root.mainloop() # tkinter mainloop
if __name__ == '__main__':
main()
````
您需要将
dbApp\u GUI
def view_command(db):
rows = db.view()
for row in rows:
print(row)
class App_GUI(): # create the main window
def __init__(self, master, db):
# other stuff elided ...
self.master.b1 = Button(self.master, text="View all", width=12, command=lambda : view_command(db))
...
def main():
db = DB()
# other stuff elided
app = App_GUI(root, db)
编辑：忘了删除self。我想出来了！除了您的更改之外，我还必须从rows=db.view（）中删除“self”。谢谢你的帮助！修订守则：
import sqlite3
from tkinter import *
from tkinter import messagebox
class DB:
def __init__(self):
self.conn = sqlite3.connect("mybooks.db")
self.cur = self.conn.cursor()
self.cur.execute(
"CREATE TABLE IF NOT EXISTS book (id INTEGER PRIMARY KEY, title TEXT, author TEXT, isbn INTEGER)")
self.conn.commit()
def __del__(self):
self.conn.close()
def view(self):
self.cur.execute("SELECT * FROM book")
rows = self.cur.fetchall()
return rows
def view_command(db):
rows=db.view()
for row in rows:
print(row)
class App_GUI(): # create the main window
def __init__(self, master, db):
self.master = master
self.master.title("My Books")
self.master.l1 = Label(self.master, text="Title")
self.master.l1.grid(row=0, column=0)
self.master.l2 = Label(self.master, text="Author")
self.master.l2.grid(row=0, column=2)
self.master.l3 = Label(self.master, text="ISBN")
self.master.l3.grid(row=1, column=0)
self.master.title_text = StringVar()
self.master.e1 = Entry(self.master, textvariable=self.master.title_text)
self.master.e1.grid(row=0, column=1)
self.master.author_text = StringVar()
self.master.e2 = Entry(self.master, textvariable=self.master.author_text)
self.master.e2.grid(row=0, column=3)
self.master.isbn_text = StringVar()
self.master.e3 = Entry(self.master, textvariable=self.master.isbn_text)
self.master.e3.grid(row=1, column=1)
self.master.list1 = Listbox(self.master, height=6, width=35)
self.master.list1.grid(row=2, column=0, rowspan=6, columnspan=2)
self.master.sb1 = Scrollbar(self.master)
self.master.sb1.grid(row=2, column=2, rowspan=6)
self.master.list1.configure(yscrollcommand=self.master.sb1.set)
self.master.sb1.configure(command=self.master.list1.yview)
self.master.b1 = Button(self.master, text="View all", width=12, command=lambda : view_command(db))
self.master.b1.grid(row=2, column=3)
self.master.b6 = Button(self.master, text="Close", width=12, command=self.master.destroy)
self.master.b6.grid(row=7, column=3)
return
###############################
# Program Main #
###############################
def main():
db = DB()
root = Tk()
def on_closing():
dd = db
if messagebox.askokcancel("Quit", "Do you want to close the application"): # ask the user if he/she wants to close the application
root.destroy()
del dd
root.protocol("WM_DELETE_WINDOW", on_closing) # catch the user closing the window
app = App_GUI(root, db) # creation of an instance
root.mainloop() # tkinter mainloop
if __name__ == '__main__':
main()
谢谢你的建议，但是现在我得到了以下错误：第25行，在view\u命令rows=db中。view（self）name错误：name“self”没有定义我已经弄明白了！我必须从rows=db.view（）中删除“self”。谢谢你的帮助！有人对我最初的问题有任何设计反馈吗？我的GUI和数据库功能应该在不同的类中，还是设计得很差？每个tkinter窗口应该是一个单独的类吗？