Python小技巧

心已赠人 2021-12-04 05:13 365阅读 0赞

1.  原地交换两个变量的值

x, y = 10, 20
    print(x, y)
    # 10, 20
    y, x = x, y
    print(x, y)
    # 20, 10

1.  三元运算符

格式: \[条件为真,返回值\] if \[表达式\] else \[条件为假,返回值\]

x = 9
    y = True if x > 10 else False
    print(y)
    # False

1.  引入模块的绝对路径

import threading
    # 直接print打印
    print(threading)
    # 结果
    # <module 'threading' from '/usr/local/Cellar/python/3.7.1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/threading.py'>

1.  获取变量拥有的方法和属性

alist = [1, 2]
    print(dir(alist))
    # 结果
    # ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']
    adict = { "a": 1, "b": 2}
    print(dir(adict))
    # 结果
    # ['__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'clear', 'copy', 'fromkeys', 'get', 'items', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values']

1.  检测Python的版本

import sys
    print(sys.version)
    # '3.7.1 (default, Nov 28 2018, 11:51:47) \n[Clang 10.0.0 (clang-1000.11.45.5)]'
    # 判断Python版本
    if sys.version_info > (3, 0):
      print("当前程序运行的是Python3")
    else:
        print("当前程序运行的是Python2")

1.  开启一个HTTP服务器,可在局域网内进行文件传输/手机读取电脑文件(同一个WiFi)

# 只有python3 有这个方法
    python3 -m http.server 端口号(默认是8000)
    # Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...
    # 浏览器访问本机IP:8000 即可访问电脑根目录
    # Windows 获取本机IP 命令: ipconfig
    # Mac / Linux 获取本机IP命令: ifconfig