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django admin - add custom form fields that are not part of the model
....models import YourModel
class YourModelForm(forms.ModelForm):
extra_field = forms.CharField()
def save(self, commit=True):
extra_field = self.cleaned_data.get('extra_field', None)
# ...do something with extra_field here...
return super(YourModelForm, self).save(c...
How to search a string in multiple files and return the names of files in Powershell?
... Move-Item doesn't have name parameter. Try adding | %{Move-Item $_.name <destination>}
– jon Z
Sep 5 '12 at 16:48
50
...
Django in / not in query
...
table1.objects.exclude(id__in=
table2.objects.filter(your_condition).values_list('id', flat=True))
The exclude function works like the Not operator you where asking for. The attribute flat = True tells to table2 query to return the value_list a...
Floating View 扩展：悬浮视图扩展，将组件转换为悬浮窗口 · App Inventor 2 中文网
...时跳转设置，授权后再创建并显示悬浮布局：
when 按钮_显示.Click() {
if FloatingView1.CheckDrawOverlayPermission() {
FloatingView1.SetupView(垂直布局_悬浮, true, 100, 500)
FloatingView1.ShowFloatingView()
} else {
FloatingView1.RequestDrawOverlayPermission...
Python None comparison: should I use “is” or ==?
My editor warns me when I compare my_var == None , but no warning when I use my_var is None .
3 Answers
...
How to include jar files with java file and compile in command prompt
...r your dependency jar files as shown below:
set classpath=C:\Users\sarath_sivan\Desktop\jars\servlet-api.jar; C:\Users\sarath_sivan\Desktop\jars\spring-jdbc-3.0.2.RELEASE; C:\Users\sarath_sivan\Desktop\jars\spring-aop-3.0.2.RELEASE;
Now, you may compile your java file. (command: javac YourJavaFile...
How can I rename a field for all documents in MongoDB?
...ormer way:
remap = function (x) {
if (x.additional){
db.foo.update({_id:x._id}, {$set:{"name.last":x.name.additional}, $unset:{"name.additional":1}});
}
}
db.foo.find().forEach(remap);
In MongoDB 3.2 you can also use
db.students.updateMany( {}, { $rename: { "oldname": "newname" } } )
...
How can I get rid of an “unused variable” warning in Xcode?
...as an "unused" attribute you can use to suppress that warning:
BOOL saved __attribute__((unused)) = [moc save:&error];
Alternatively (in case LLVM doesn't support the above), you could split the variable declaration into a separate line, guaranteeing that the variable would be "used" whether ...
Print multiple arguments in Python
... isn't a function in Python 2. You can, however, import this behavior from __future__:
from __future__ import print_function
Use the new f-string formatting in Python 3.6:
print(f'Total score for {name} is {score}')
sha...
What are 'get' and 'set' in Swift?
...y can set the members value to anything less than 2:
class family {
var _members:Int = 2
var members:Int {
get {
return _members
}
set (newVal) {
if newVal >= 2 {
_members = newVal
} else {
println('error: cannot have family with less than 2 members')
...