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MongoDB atomic “findOrCreate”: findOne, insert if nonexistent, but do not update
as the title says, I want to perform a find (one) for a document, by _id, and if doesn't exist, have it created, then whether it was found or was created, have it returned in the callback.
...
TypeError: 'NoneType' object is not iterable in Python
...r a variable containing None. The operation was performed by invoking the __iter__ method on the None.
None has no __iter__ method defined, so Python's virtual machine tells you what it sees: that NoneType has no __iter__ method.
This is why Python's duck-typing ideology is considered bad. The...
Python Pandas: Get index of rows which column matches certain value
...tion and then create slices for use in iloc(). The only thing I see is get_loc, but it cannot take an array.
– sheridp
Apr 21 '16 at 0:47
3
...
Convert an image (selected by path) to base64 string
...e to retrieve the base64 string
public static string ImageToBase64(string _imagePath)
{
string _base64String = null;
using (System.Drawing.Image _image = System.Drawing.Image.FromFile(_imagePath))
{
using (MemoryStream _mStream = new MemoryStream())
...
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 ...
Use 'import module' or 'from module import'?
... * can be particularly useful, if using it as: if(windows):\n\t from module_win import * \n else: \n\t from module_lin import *. Then your parent module can potentially contain OS independent function names, if the function names in module_lin & module_win have same names. It's like conditionall...
How do I remove a property from a JavaScript object?
...
Another alternative is to use the Underscore.js library.
Note that _.pick() and _.omit() both return a copy of the object and don't directly modify the original object. Assigning the result to the original object should do the trick (not shown).
Reference: link _.pick(object, *keys)
Return...
error C2780: \'void __cdecl std::sort(_RI,_RI,_Pr)\' : expects 3 argum...
error C2780: 'void __cdecl std::sort(_RI,_RI,_Pr)' : expects 3 arguments - 2 providedprog7.cpp(8) :error C2780:'void __cdecl std::sort(_RI,_RI,_Pr)' : expects 3 arguments - 2 provided C: Pr...prog7.cpp(8) : error C2780: 'void __cdecl std::sort(_RI,_RI,_Pr)' : expects 3 arguments - 2 provided
C:...
How to reverse a string in Go?
...ints.
n := 0
rune := make([]rune, len(input))
for _, r := range input {
rune[n] = r
n++
}
rune = rune[0:n]
// Reverse
for i := 0; i < n/2; i++ {
rune[i], rune[n-1-i] = rune[n-1-i], rune[i]...
Generate JSON string from NSDictionary in iOS
...ke easier to read).
@interface NSDictionary (BVJSONString)
-(NSString*) bv_jsonStringWithPrettyPrint:(BOOL) prettyPrint;
@end
.
@implementation NSDictionary (BVJSONString)
-(NSString*) bv_jsonStringWithPrettyPrint:(BOOL) prettyPrint {
NSError *error;
NSData *jsonData = [NSJSONSerial...