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Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
C Macro definition to determine big endian or little endian machine?
...
Code supporting arbitrary byte orders, ready to be put into a file called order32.h:
#ifndef ORDER32_H
#define ORDER32_H
#include <limits.h>
#include <stdint.h>
#if CHAR_BIT != 8
#error "unsupported char size"
#endif
enum
{
O32_LITTLE_ENDIAN = 0x03020100ul,
O32_BIG_END...
Can you “ignore” a file in Perforce?
...n of those file-types through using lines like the below in the p4 protect table:
write user * * -//.../*.suo
write user * * -//.../*.obj
write user * * -//.../*.ccscc
I remember doing this before, but I don't have the necessary permissions to test this here. Check out Perforce's Sysadmin guide a...
How to execute IN() SQL queries with Spring's JDBCTemplate effectivly?
...
You should probably insert the values into a temporary table and build the condition using WHERE NOT EXISTS (SELECT ...).
– yawn
May 26 '10 at 11:17
6
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std::enable_if to conditionally compile a member function
... I want to use std::enable_if to choose between two member-functions and allow only one of them to be used.
7 Answers
...
How to track down a “double free or corruption” error
...
If you're using glibc, you can set the MALLOC_CHECK_ environment variable to 2, this will cause glibc to use an error tolerant version of malloc, which will cause your program to abort at the point where the double free is done.
You can set this from gdb by using ...
django change default runserver port
...
You can't run the development server programmatically, so a custom command won't work unless it calls the shell using something like call. If this solution works for you please make sure to mark it as solved.
– Pablo Albornoz
May 13 '1...
How to get ER model of database from server with Workbench
...
Migrate your DB "simply make sure the tables and columns exist".
Recommended to delete all your data (this freezes MySQL Workbench on my MAC everytime due to "software out of memory..")
Open MySQL Workbench
click + to make MySQL connection
enter credentials...
Flask-SQLalchemy update a row's information
...e many objects to be updated.
If you want to give add_user permission to all the admins,
rows_changed = User.query.filter_by(role='admin').update(dict(permission='add_user'))
db.session.commit()
Notice that filter_by takes keyword arguments (use only one =) as opposed to filter which takes an e...
What does the line “#!/bin/sh” mean in a UNIX shell script?
...
When you try to execute a program in unix (one with the executable bit set), the operating system will look at the first few bytes of the file. These form the so-called "magic number", which can be used to decide the format of the program and how to execute it.
#! corresponds to the ...