大约有 41,000 项符合查询结果（耗时：0.0510秒） [XML]
How do I print out the contents of an object in Rails for easy debugging?
...n't give me what I want, I'll switch to .to_yaml.
class User
attr_accessor :name, :age
end
user = User.new
user.name = "John Smith"
user.age = 30
puts user.inspect
#=> #<User:0x423270c @name="John Smith", @age=30>
puts user.to_yaml
#=> --- !ruby/object:User
#=> age: 30
#=> nam...
How to use Python's pip to download and keep the zipped files for a package?
...
Note that pip download also supports -r requirements.txt so you can easily download them all from an internet-connected machine then copy to an offline machine and install how the above commenters mentioned
– Hawkins
A...
How to get a Docker container's IP address from the host
...
The --format option of inspect comes to the rescue.
Modern Docker client syntax is:
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name_or_id
Old Docker client syntax is:
docker inspect -...
PHP session lost after redirect
...t, carry out these usual checks:
Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php declaration before anything else. Also ensure there are no whitespaces/tabs before the ...
Check if a table exists in Rails
I have a rake task that won't work unless a table exists. I'm working with more than 20 engineers on a website so I want to make sure they have migrated the table before they can do a rake task which will populate that respective table.
...
What's the fuss about Haskell? [closed]
...
The way it was pitched to me, and what I think is true after having worked on learning on Haskell for a month now, is the fact that functional programming twists your brain in interesting ways: it forces you to think about familiar problems in different ways: instead of loops, think in maps an...
What should my Objective-C singleton look like? [closed]
My singleton accessor method is usually some variant of:
26 Answers
26
...
What does it mean in shell when we put a command inside dollar sign and parentheses: $(command)
...understand following line of code in shell. It is used to get the current working directory. I am aware that $(variable) name return the value inside the variable name, but what is $(command) supposed to return? Does it return the value after executing the command? In that case, we can use ` t...
Are HTTP headers case-sensitive?
...
For anyone looking, here is where RFC 7230 explicitly states that field headers should be treated as case insensitive: tools.ietf.org/html/rfc7230#section-3.2
– J Z
Aug 9 '17 at 19:12
...
Manipulate a url string by adding GET parameters
... to URLs that may and may not contain GET parameters without repeating ? or & .
15 Answers
...