大约有 17,000 项符合查询结果(耗时:0.0562秒) [XML]

https://stackoverflow.com/ques... 

Is 'switch' faster than 'if'?

... your specific questions: Clang generates one that looks like this: test_switch(char): # @test_switch(char) movl %edi, %eax cmpl $19, %edi jbe .LBB0_1 retq .LBB0_1: jmpq *.LJTI0_0(,%rax,8) jmp void call<0u&g...
https://stackoverflow.com/ques... 

Replacing some characters in a string with another character

...zLMN and I want to replace all the occurrences of x , y , and z with _ . 5 Answers ...
https://stackoverflow.com/ques... 

Python argparse mutual exclusive group

... add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive. What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd hav...
https://stackoverflow.com/ques... 

How to compare type of an object in Python?

... isinstance works: if isinstance(obj, MyClass): do_foo(obj) but, keep in mind: if it looks like a duck, and if it sounds like a duck, it is a duck. EDIT: For the None type, you can simply do: if obj is None: obj = MyClass() ...
https://stackoverflow.com/ques... 

Getting started with Haskell

... to stick. Now, in learning various imperative/OO languages (like C, Java, PHP), exercises have been a good way for me to go. But since I don't really know what Haskell is capable of and because there are many new concepts to utilize, I haven't known where to start. ...
https://stackoverflow.com/ques... 

sqlalchemy: how to join several tables by one query?

...integer primary keys for everything, but whatever): class User(Base): __tablename__ = 'users' email = Column(String, primary_key=True) name = Column(String) class Document(Base): __tablename__ = "documents" name = Column(String, primary_key=True) author_email = Column(Strin...
https://stackoverflow.com/ques... 

Javascript regex returning true.. then false.. then true.. etc [duplicate]

... /^[^-_]([a-z0-9-_]{4,20})[^-_]$/gi; You're using a g (global) RegExp. In JavaScript, global regexen have state: you call them (with exec, test etc.) the first time, you get the first match in a given string. Call them again and ...
https://stackoverflow.com/ques... 

Project structure for Google App Engine

... had trouble with packages. Just make sure each of your sub folders has an __init__.py file. It's ok if its empty. Boilerplate files These hardly vary between projects app.yaml: direct all non-static requests to main.py main.py: initialize app and send it all requests Project lay-out static...
https://stackoverflow.com/ques... 

Get name of object or class

... use standard IIFE (for example with TypeScript) var Zamboch; (function (_Zamboch) { (function (Web) { (function (Common) { var App = (function () { function App() { } App.prototype.hello = function () { co...
https://stackoverflow.com/ques... 

How to print a dictionary line by line in Python?

... I do print(json.dumps(cars, indent=4, ensure_ascii=False)) because otherwise non-ASCII characters are unreadable. – Boris Apr 22 at 16:36 add a ...