Python的隐藏特性

Hidden features of Python(Python的隐藏特性)

本文介绍了Python的隐藏特性的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

What are the lesser-known but useful features of the Python programming language?

  • Try to limit answers to Python core.
  • One feature per answer.
  • Give an example and short description of the feature, not just a link to documentation.
  • Label the feature using a title as the first line.

Quick links to answers:

  • Argument Unpacking
  • Braces
  • Chaining Comparison Operators
  • Decorators
  • Default Argument Gotchas / Dangers of Mutable Default arguments
  • Descriptors
  • Dictionary default .get value
  • Docstring Tests
  • Ellipsis Slicing Syntax
  • Enumeration
  • For/else
  • Function as iter() argument
  • Generator expressions
  • import this
  • In Place Value Swapping
  • List stepping
  • __missing__ items
  • Multi-line Regex
  • Named string formatting
  • Nested list/generator comprehensions
  • New types at runtime
  • .pth files
  • ROT13 Encoding
  • Regex Debugging
  • Sending to Generators
  • Tab Completion in Interactive Interpreter
  • Ternary Expression
  • try/except/else
  • Unpacking+print() function
  • with statement

解决方案

Chaining comparison operators:

>>> x = 5
>>> 1 < x < 10
True
>>> 10 < x < 20 
False
>>> x < 10 < x*10 < 100
True
>>> 10 > x <= 9
True
>>> 5 == x > 4
True

In case you're thinking it's doing 1 < x, which comes out as True, and then comparing True < 10, which is also True, then no, that's really not what happens (see the last example.) It's really translating into 1 < x and x < 10, and x < 10 and 10 < x * 10 and x*10 < 100, but with less typing and each term is only evaluated once.

这篇关于Python的隐藏特性的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持编程学习网!

本文标题为:Python的隐藏特性

基础教程推荐