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Why doesn't a python dict.update() return the object?
...
Python's mostly implementing a pragmatically tinged flavor of command-query separation: mutators return None (with pragmatically induced exceptions such as pop;-) so they can't possibly be confused with accessors (and in the same vein, assignment is not an expression, the statement-expressi...
How to break out from a ruby block?
...fers control out of the block, out of the iterator that invoked the block, and to the first expression following the invocation of the iterator:
f.each do |line| # Iterate over the lines in file f
break if line == "quit\n" # If this break statement is executed...
puts eval(line)
en...
Convert a String representation of a Dictionary to a dictionary?
... literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
For example:
>>> eval("shutil.rmtree('mongo')")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
File "/opt/Python...
How do I set the time zone of MySQL?
...at +02:00 is an offset. Europe/Berlin is a timezone (that has two offsets) and CEST is a clock time that corresponds to a specific offset.
@@session.time_zone variable
SELECT @@session.time_zone;
To set it use either one:
SET time_zone = 'Europe/Helsinki';
SET time_zone = "+00:00";
SET @@sessio...
Use underscore inside Angular controllers
...
When you include Underscore, it attaches itself to the window object, and so is available globally.
So you can use it from Angular code as-is.
You can also wrap it up in a service or a factory, if you'd like it to be injected:
var underscore = angular.module('underscore', []);
underscore.fac...
How to drop a PostgreSQL database if there are active connections to it?
...s will drop existing connections except for yours:
Query pg_stat_activity and get the pid values you want to kill, then issue SELECT pg_terminate_backend(pid int) to them.
PostgreSQL 9.2 and above:
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
WHERE pg_stat_activity.datn...
9个常用iptables配置实例 - 更多技术 - 清泛网 - 专注C/C++及内核技术
9个常用iptables配置实例iptables命令可用于配置Linux的包过滤规则，常用于实现防火墙、NAT。咋一看iptables的配置很复杂，掌握规律后，其实用iptables完成指定任务...iptables命令可用于配置Linux的包过滤规则，常用于实现防火墙、NAT。...
Fully custom validation error message with Rails
...
Now, the accepted way to set the humanized names and custom error messages is to use locales.
# config/locales/en.yml
en:
activerecord:
attributes:
user:
email: "E-mail address"
errors:
models:
user:
attributes:
e...
Spring Boot: How can I set the logging level with application.properties?
...config file (log4j.xml or logback.xml) to the src/main/resources directory and configure to your liking.
You can enable debug logging by specifying --debug when starting the application from the command-line.
Spring Boot provides also a nice starting point for logback to configure some defaults, col...
How do you use script variables in psql?
...
Postgres variables are created through the \set command, for example ...
\set myvariable value
... and can then be substituted, for example, as ...
SELECT * FROM :myvariable.table1;
... or ...
SELECT * FROM table1 WHERE :myvariable IS NULL;
edit: As of psql 9.1, varia...