1 def show(name,age,email): 2     #普通方法 3     print(‘your name is: %s \nyour age is: %i \nyour email is: %s‘ %(name,age,email)) 4     #更加清晰引用的方法 5     print(‘your name is: %(name)s \n your age is: %(age)i \nyour email is: %(email)s‘ %{‘name‘:name,‘age‘:age,‘email‘:email})  6     #str.format()字符串格式化方法 7     print(‘your name is: {name} \nyour age is {age} \nyour email is: {email}‘.format(name = name,age = age,email = email)) 8   9 if __name__ == ‘__main__‘:10     show(‘wwl‘,24,‘wwl1991@yeah.net‘)

官网：　　https://pip.pypa.io/en/latest/Python 3.4版本内置了pip 存放在python安装路径的Scripts目录，只需要把这个路径加到系统的path路径即可。
安装包：pip install SomePackage
卸载包：pip uninstall SomePackage
升级包：pip install --upgrade SomePackage
显示安装包：pip list
显示安装包哪些需要升级：pip list --outdated
显示包信息：pip show SomePackage
显示安装包包含哪些文件：pip show --files SomePackage

$ pip install SomePackage            # latest version$ pip install SomePackage==1.0.4     # specific version$ pip install ‘SomePackage>=1.0.4‘     # minimum version

Stackoverflow上面关于pip的讨论：　　http://stackoverflow.com/questions/4750806/how-to-install-pip-on-windows/　　http://stackoverflow.com/questions/2436731/does-python-have-a-package-module-management-system/13445719　　http://stackoverflow.com/questions/3220404/why-use-pip-over-easy-install

pylint官网：    http://pylint.org/Pylint 默认使用的代码风格是 PEP 8

C ? X: Y当C为True的时候取值X，否则取值YPython等价形式 X if C else Y>>> a = 3>>> print(‘haha‘) if a <5 else ‘hehe‘haha>>> print(‘haha‘) if a <2 else ‘hehe‘‘hehe‘

Python中没有switch...case...以下两种方法代替：1.if...elif...if x == 0:    return(‘000‘)elif x == 1:    return(‘1111‘)2.{}.get(x){0:‘000‘,1:‘1111‘}.get(0)

>>> x = 1>>> y = 2>>> assert x == y,‘not equals‘Traceback (most recent call last):  File "<pyshell#2>", line 1, in <module>    assert x == y,‘not equals‘AssertionError: not equals等价于下面>>> if __debug__ and not x == y:    raise AssertionError(‘not equals‘)Traceback (most recent call last):  File "<pyshell#13>", line 2, in <module>    raise AssertionError(‘not equals‘)AssertionError: not equals其中__debug__为True而且不能修改
使用断言是有代价的，它会对性能产生一定影响。禁用断言的方法是在运行脚本时候加上-O（忽略与断言相关的语句）
断言是被设计用来捕获用户定义的约束的，而不是用来捕获程序本身错误

常用方法：temp = xx = yy = temp推荐方法：x,y = y,x解析：先计算=右边的值为（y,x）然后分别赋值给x,y变量性能对比：>>> import timeit>>> timeit.Timer(‘x,y = y,x‘,‘x = 1;y = 2‘).timeit()0.03071109231768787>>> timeit.Timer(‘temp = x;x = y;y = temp‘,‘x = 1;y = 2‘).timeit()0.035570626849676046

if x and y在x为False的时候y不再计算if x or y在x为True的时候y不再计算x和y表达式的前后顺序会对程序执行时间造成影响。

Enums have been added to Python 3.4 as described in PEP 435. It has also been backported to 3.3, 3.2, 3.1, 2.7, 2.6, 2.5, and 2.4 on pypi.To use backports, do $ pip install enum34, installing enum (no numbers) will install a completely different and incompatible version.from enum import EnumAnimal = Enum(‘Animal‘, ‘ant bee cat dog‘)等价于class Animals(Enum):    ant = 1    bee = 2    cat = 3    dog = 4以上是下面链接的搬运：http://stackoverflow.com/questions/36932/how-can-i-represent-an-enum-in-python

对应内建的基本类型来说使用type()进行类型检查是ok的；基于内建类型扩展的用户自定义类型，type并不能准确返回结果；

>>> import types
>>> class UserInt(int):
　　　　def __init__(self,val=0):
　　　　self._val = int(val)

>>> n = UserInt(2)
>>> n
2
>>> type(n)
<class ‘__main__.UserInt‘>
>>> isinstance(n,int)
True