大约有 40,000 项符合查询结果(耗时:0.0501秒) [XML]

https://stackoverflow.com/ques... 

How to check if a value exists in a dictionary (python)

...ed for lookup operations: >>> type(d.viewvalues()) <type 'dict_values'> >>> type(d.values()) <type 'list'> >>> type(d.itervalues()) <type 'dictionary-valueiterator'> EDIT2: As per request in comments... >>> T(lambda : 'four' in d.itervalues()...
https://stackoverflow.com/ques... 

ActiveModel::ForbiddenAttributesError when creating new user

...ntroller < ApplicationController def create @user = User.new(user_params) # ... end private def user_params params.require(:user).permit(:username, :email, :password, :salt, :encrypted_password) end end ...
https://stackoverflow.com/ques... 

Unexpected Caching of AJAX results in IE8

... not as simple to solve. The trick is to use Sys.Net.WebRequestManager.add_invokingRequest method in the event handler change the request url: networkRequestEventArgs._webRequest._url = networkRequestEventArgs._webRequest._url + '&nocache=' + new Date().getMilliseconds(); I've blogged about...
https://stackoverflow.com/ques... 

Null coalescing in powershell

...ms -ne $null [string]::Join(', ', ($instances | ForEach-Object -Process { $_.GetType() })) # Result: System.String, System.Int32, System.Int32, System.String, System.Object[], System.Boolean, System.Boolean -eq works similarly, which is useful for counting null entries: ($null, 'a', $null -eq $n...
https://stackoverflow.com/ques... 

Is it better to use Enumerable.Empty() as opposed to new List() to initialize an IEnumerable

...ems as an Enumerable: public class Person { private IList<Role> _roles; public Person() { this._roles = new List<Role>(); } public string Name { get; set; } public void AddRole(Role role) { //implementation } public IEnumerable<...
https://stackoverflow.com/ques... 

Looping through a hash, or using an array in PowerShell

... how: $hash = @{ a = 1 b = 2 c = 3 } $hash.Keys | % { "key = $_ , value = " + $hash.Item($_) } Output: key = c , value = 3 key = a , value = 1 key = b , value = 2 share | improve th...
https://stackoverflow.com/ques... 

Toggle button using two image on different state

... <ToggleButton android:id="@+id/toggle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@drawable/check" <!--check.xml--> android:layout_margin="10dp" android:textOn="" android:textOff="...
https://stackoverflow.com/ques... 

Objective-C categories in static library

...search for "Other Linker Flags", click the + button, and add '-ObjC'. '-all_load' and '-force_load' are no longer needed. Details: I found some answers on various forums, blogs and apple docs. Now I try make short summary of my searches and experiments. Problem was caused by (citation from apple Tec...
https://stackoverflow.com/ques... 

Python pandas: fill a dataframe row by row

... I see. So the loc attribute of the data frame defines a special __setitem__ that does the magic I suppose. – xApple Jun 13 '13 at 16:24 ...
https://stackoverflow.com/ques... 

Python super() raises TypeError

...You have to design any methods that need to multiply-inherit (most notably __init__) to pass through arguments in a clean and sensible way, otherwise you'll get TypeErrors or worse debugging problems when someone tries to multiply-inherit using your class. Unless you've really designed to support MI...