csv.reader.close（）引发一个属性对象

Question

使用以下代码，我得到错误：

PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'Student Data.csv'

但是如果我添加r.close()，它会返回错误：

^{pr2}$

小键盘的代码是2580，CSV的格式是

bakerg,ict,George Baker,11HM,NORMAL

代码：

from tkinter import *
import csv
import os
login = "bakerg"

def upgradetoadmin():
    global masterpassword
    masterpassword = []
    def one():
        masterpassword.append("1")
        arraycheck()
    def two():
        masterpassword.append("2")
        arraycheck()
    def three():
        masterpassword.append("3")
        arraycheck()
    def four():
        masterpassword.append("4")
        arraycheck()
    def five():
        masterpassword.append("5")
        arraycheck()
    def six():
        masterpassword.append("6")
        arraycheck()
    def seven():
        masterpassword.append("7")
        arraycheck()
    def eight():
        masterpassword.append("8")
        arraycheck()
    def nine():
        masterpassword.append("9")
        arraycheck()
    def zero():
        masterpassword.append("0")
        arraycheck()
    def clear():
        global masterpassword
        masterpassword = []
    def arraycheck():
        global masterpassword
        if len(masterpassword) == 4:
            if masterpassword == ['2','5','8','0']:
                print("Success")
                r = csv.reader(open('Student Data.csv'))
                lines = [l for l in r]
                print(lines)
                i = 0
                for item in lines:
                    if item[0] == login:
                        print(item)
                        print("YAY")
                        item[4] = "ADMIN"
                        print(item)
                        os.remove('Student Data.csv')
                        writer = csv.writer(open('Student Data.csv', 'w'))
                        writer.writerows(lines)

                print(login + " is now an admin")
            else:
                print("Invalid Code")
            masterpassword = []

    keypadwindow = Tk()
    keypadwindow.iconbitmap("hXYTZdJy.ico")
    keypadwindow.title("ADMIN UPGRADER")
    Button(keypadwindow, text="1", height = 4, width = 10, command = one).grid(column = 0, row = 0)
    Button(keypadwindow, text="2", height = 4, width = 10, command = two).grid(column = 1, row = 0)
    Button(keypadwindow, text="3", height = 4, width = 10, command = three).grid(column = 2, row = 0)
    Button(keypadwindow, text="4", height = 4, width = 10, command = four).grid(column = 0, row = 1)
    Button(keypadwindow, text="5", height = 4, width = 10, command = five).grid(column = 1, row = 1)
    Button(keypadwindow, text="6", height = 4, width = 10, command = six).grid(column = 2, row = 1)
    Button(keypadwindow, text="7", height = 4, width = 10, command = seven).grid(column = 0, row = 2)
    Button(keypadwindow, text="8", height = 4, width = 10, command = eight).grid(column = 1, row = 2)
    Button(keypadwindow, text="9", height = 4, width = 10, command = nine).grid(column = 2, row = 2)
    Button(keypadwindow, text="0", height = 4, width = 10, command = zero).grid(column = 1, row = 3)
    Button(keypadwindow, text="CLEAR", height = 4, width = 10, command = clear).grid(column = 2, row = 3)
    keypadwindow.mainloop()

upgradetoadmin()

Answer 1

我想你应该有这个：

                f = open('Student Data.csv', 'w')
                writer = csv.writer(f)
                writer.writerows(lines)
                f.close() 

Answer 2

csv.reader没有close方法（或与此相关的任何其他常规方法）。相反，它将一个file对象作为它的参数，并对其进行迭代，从而逐个生成行。在

您应该对file对象本身调用close()：

my_file = open('Student Data.csv')
r = csv.reader(my_file)
...
my_file.close()

当然，with-statement会自动为您执行此操作：

^{pr2}$

Answer 3

您需要关闭open返回的file对象，而不是csv.reader。在

使用^{}块为您关闭文件：

with open('Student Data.csv') as f:
    r = csv.reader(f)
    # ...