大约有 46,000 项符合查询结果（耗时：0.0416秒） [XML]
What is the difference between save and insert in Mongo DB?
...
Save Vs Insert :
In your given examples, the behavior is essentially the same.
save behaves differently if it is passed with an "_id" parameter.
For save, If the document contains _id, it will upsert querying the collection on the _id field, If not, it will insert.
If a document does not...
Git Symlinks in Windows
...es and replaces them with symlinks on windows using mklink. while this actually works for us the --assume-unchanged part doesn't. on switching to another branch git says the symlink files are changed and need to be commited first, while git status says there are no changes..any idea?
...
Should all Python classes extend object?
...inheritance are different in ways that I won't even try to summarize here. All good documentation that I've seen about MI describes new-style classes.
Finally, old-style classes have disappeared in Python 3, and inheritance from object has become implicit. So, always prefer new style classes unless...
Convert PDF to clean SVG? [closed]
...t they often lose the font data, but don't seem to approximate a good, installed font. How does PDF display it if SVG can't?
– DanRedux
Apr 23 '12 at 21:30
...
How to “EXPIRE” the “HSET” child key in redis?
I need to expire all keys in redis hash, which are older than 1 month.
11 Answers
11
...
Traverse a list in reverse order in Python
... are reversed on the fly while traversing! This is an important feature of all these iteration functions (which all end on “ed”).
– Konrad Rudolph
Feb 9 '09 at 19:10
9
...
Python name mangling
...ld Python guys despise this default - but it is the default anyway, so I really recommend you to follow it, even if you feel uncomfortable.
If you really want to send the message "Can't touch this!" to your users, the usual way is to precede the variable with one underscore. This is just a conventi...
Is this object-lifetime-extending-closure a C# compiler bug?
...L_000e: ldloc.0
IL_000f: ldc.r8 42
IL_0018: ldc.r8 1
IL_0021: call float64 [mscorlib]System.Math::Pow(float64, float64)
IL_0026: stfld float64 ConsoleApplication1.Program/Foo/'<>c__DisplayClass1'::capturedVariable
IL_002b: ldarg.0
IL_002c: ldloc.0
IL_002d: ldftn ins...
Importing modules from parent folder
...t can matter if somewhere else then the parentdir, but in one of the paths allready specified in sys.path, there is another module with the name 'mymodule'. Inserting the parentdir as the first element of the sys.path list assures that the module from parentdir will be imported instead.
...
How to split a string literal across multiple lines in C / Objective-C?
...
There are two ways to split strings over multiple lines:
Using \
All lines in C can be split into multiple lines using \.
Plain C:
char *my_string = "Line 1 \
Line 2";
Objective-C:
NSString *my_string = @"Line1 \
Line2";
Better approach
Th...