小编GTA*_*prx的帖子

突然我收到一个错误，说TypeError: on_delete must be callable.我不知道如何解决这个错误，因为我field=models.ForeignKey(default=1, on_delete='CASCADE', to='main.Category'),在我的代码中没有看到任何地方提到。

  File "/home/arch/myproject/main/migrations/0014_auto_20191025_1154.py", line 6, in <module>
    class Migration(migrations.Migration):
  File "/home/arch/myproject/main/migrations/0014_auto_20191025_1154.py", line 47, in Migration
    field=models.ForeignKey(default=1, on_delete='CASCADE', to='main.Category'),
  File "/home/arch/.local/lib/python3.8/site-packages/django/db/models/fields/related.py", line 801, in __init__
    raise TypeError('on_delete must be callable.')

类型错误：on_delete 必须是可调用的。

我正在尝试使用进度条模块，但收到以下错误。TypeError: 'module' object is not callable我正在测试文档中的确切片段。

import time
import progressbar

for i in progressbar.progressbar(range(100)):
    time.sleep(0.02)

I'm trying to insert a string into another string like you would with append() but rather than at the end I'd like to put it before the occurrence of ".xlsx".

    string docName;
    docName = "../Toyota Tacoma " + customer.toStdString() + " .xlsx";
    if(sold = true){
        docName = docName.append("(sold)");
    }
    doc.CreateDocument(docName);

This code just appends "(sold)" after ".xlsx"

在我的 Debian 服务器上，如果我运行python -V它说它正在使用，Python 2.7.13即使我安装了 Python 3。

为什么现在不默认使用 Python 3？我正在尝试部署一个 Django 应用程序，它期待 Python 3。