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What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?
...
This part is new. Expression Literals
When you have an expression (M_PI / 16 for example) you should put it inside parenthesis.
This syntax works for numeral expressions, booleans, finding an index in a (C-) string, boolean values, enum constants, and even character strings!
NSNumber *piO...
How to sort an IEnumerable
...myList = myEnumerable.ToList();
myList.Sort();
Based on your comment:
_components = (from c in xml.Descendants("component")
let value = (string)c
orderby value
select value
)
.Distinct()
.ToList();
or
_com...
How to dynamically compose an OR query filter in Django?
...'s say with a list
# of db fields that can change like the following
# list_with_strings = ['dbfield1', 'dbfield2', 'dbfield3']
# init our q objects variable to use .add() on it
q_objects = Q(id__in=[])
# loop trough the list and create an OR condition for each item
for item in list:
q_objects...
How to make MySQL handle UTF-8 properly
... answer - You should almost always be using the utf8mb4 charset and utf8mb4_unicode_ci collation.
To alter database:
ALTER DATABASE dbname CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
See:
Aaron's comment on this answer How to make MySQL handle UTF-8 properly
What's the difference betwee...
Update MongoDB field using value of another field
...; {
requests.push( {
'updateOne': {
'filter': { '_id': document._id },
'update': { '$set': { 'name': document.name } }
}
});
if (requests.length === 500) {
//Execute per 500 operations and re-init
db.collection.bulkWrite(requests)...
How do I raise the same Exception with a custom message in Python?
...Note that you can add whatever you like to err. For example err.problematic_array=[1,2,3].
Edit: @Ducan points in a comment the above does not work with python 3 since .message is not a member of ValueError. Instead you could use this (valid python 2.6 or later or 3.x):
try:
try:
raise...
Basic http file downloading and saving to disk in python?
...URLopener is deprecated.
And when used you will get error as below:
url_opener = urllib.URLopener() AttributeError: module 'urllib' has no
attribute 'URLopener'
So, try:
import urllib.request
urllib.request.urlretrieve(url, filename)
...
Print current call stack from a method in Python code
...port traceback
def f():
g()
def g():
for line in traceback.format_stack():
print(line.strip())
f()
# Prints:
# File "so-stack.py", line 10, in <module>
# f()
# File "so-stack.py", line 4, in f
# g()
# File "so-stack.py", line 7, in g
# for line in traceback.form...
undefined reference to `WinMain@16'
...>
int main()
{
MessageBox( 0, "Blah blah...", "My Windows app!", MB_SETFOREGROUND );
}
Now let's build it using GNU toolchain (i.e. g++), no special options. Here gnuc is just a batch file that I use for that. It only supplies options to make g++ more standard:
C:\test> gnuc x.cpp
C:...
How to initialize std::vector from C-style array?
...
Don't forget that you can treat pointers as iterators:
w_.assign(w, w + len);
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