Python基础教程（第2版）读书笔记

作者简介：Magnus Lie Hetland(http://hetland.org/)挪威科技大学副教授。

第一章基础知识
str()、repr()、反引号的使用与区别：str 和int、long一样是一种类型，而repr()则是一个函数。
input()和raw_input()的区别：input()会把字符串当字符串，数值当数值；而raw_input()则是把原始数据存放在字符串里。
长字符串、原始字符串和Unicode
长字符串的使用：

>>> print '''adfjkl adfkldsj''' 
adfjkl adfkldsj

原始字符串： print r'C:\nowhere'在字符串前添加r，但也要注意结尾处的\
Unicode：u"Hello,world"
第二章：列表和元组
python包含6种内建的序列，最常用的是:列表和元组。通用的序列操作有：索引、分片、加、乘以及成员资格(in)。
内建函数：len min max
总共的内联函数有：

		Built-in Functions
abs()	divmod()	input()	open()	staticmethod()
all()	enumerate()	int()	ord()	str()
any()	eval()	isinstance()	pow()	sum()
basestring()	execfile()	issubclass()	print()	super()
bin()	file()	iter()	property()	tuple()
bool()	filter()	len()	range()	type()
bytearray()	float()	list()	raw_input()	unichr()
callable()	format()	locals()	reduce()	unicode()
chr()	frozenset()	long()	reload()	vars()
classmethod()	getattr()	map()	repr()	xrange()
cmp()	globals()	max()	reversed()	zip()
compile()	hasattr()	memoryview()	round()	__import__()
complex()	hash()	min()	set()	apply()
delattr()	help()	next()	setattr()	buffer()
dict()	hex()	object()	slice()	coerce()
dir()	id()	oct()	sorted()	intern()

列表（python的苦力）的操作：
append
count
extend
index
insert
pop
remove
reverse
sort
sorted(x)
高级排序
元组：不可变序列
元组的意义：元组可以在映射中当作键使用，而列表不行。
第三章：使用字符串
%格式化字符串

>>> format="h %s %s enough "
 >>> v=('a','b')
 >>> print format % v h a b enough 

模板字符串

from string import Template 
>>> s=Template('$x,glorious $x')
>>> s.substitute(x='lsm')

%字符，转换开始
转换标志：-表示左对齐，+表示在转换前加上正负号，""表示在字符串前保留空格，0表示值若不够则用0填充
转换类型：
int(x [,base ])         将x转换为一个整数    
long(x [,base ])        将x转换为一个长整数    
float(x )               将x转换到一个浮点数    
complex(real [,imag ])  创建一个复数    
str(x )                 将对象 x 转换为字符串    
repr(x )                将对象 x 转换为表达式字符串    
eval(str )              用来计算在字符串中的有效Python表达式,并返回一个对象    
tuple(s )               将序列 s 转换为一个元组    
list(s )                将序列 s 转换为一个列表    
chr(x )                 将一个整数转换为一个字符    
unichr(x )              将一个整数转换为Unicode字符    
ord(x )                 将一个字符转换为它的整数值    
hex(x )                 将一个整数转换为一个十六进制字符串    
oct(x )                 将一个整数转换为一个八进制字符串    
find()
join

>>> p='+'
>>>qq=["a","b"] 
>>> qq.join(p) 
Traceback (most recent call last):   File "<pyshell#73>", line 1, in <module>     qq.join(p) AttributeError: 'list' object has no attribute 'join' 
>>> p.join(qq) 
'a+b' 
>>> p

lower
replace
split

>>> import string 
>>> string .capwords("that's all ,folk")
 "That's All ,folk"

strip
去除两边的空格
translate()

>>> test='this is an incredible test' 
>>> from string import maketrans 
>>> table=maketrans('a', 'e') 
>>> test.translate(table)
 'this is en incredible test'

第四章：字典，当索引不好用时
基本的字典操作：
len(d)
d[k]
del d[k]
字典的格式化字符串
字典方法
clear()
copy()
fromkeys()
get()
has_key()
items()iteritems()
keys()iterkeys()
pop() popitem()
setdefault() update()
values() itervalues()
第五章： 条件、循环和其他语句
复制魔法：
序列解包

>>> x,y,z=1,2,3
 >>> x 
1 
>>> y 
2 
>>> z 
3

链式赋值

>>> x=y=z=4 
>>> x 
4

增量赋值

代码嵌套

name=raw_input("what's your name?")

if name.endswith('ming'):
    if name.startswith('Mr'):
        print 'hello,Mr.Ming'
    elif name.startswith('Mrs'):
        print 'hello,mrs,ming'
    else:
        print 'hello'
else:
    print 'hello ,stranger'

断言的使用
一些迭代工具
并行迭代

names=['a','b','c']
ages=[1,2,3]
#for i in range(len(names)):
#   print names[i],'is',ages[i],'years old'

for name,age in zip(names,ages):
    print name,'is',age,'yeas old'

编号迭代
翻转和排序迭代
列表推导式---轻量级循环
[x*x for x in range(10)]
使用exec和eval执行和求值字符串
exec
第六章：抽象
callable()：判断函数是否可以调用
记录函数：文档字符串

参数存储在局部作用域内，不可改变
关键参数与默认值
收集参数

作用域的定义
globals()['parameter']
global
递归的使用

python中“函数式编程”有用的函数
map
filter
reduce

>>> map(str,range(10))
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
>>> map(str,range(10))
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
>>> def funx(x):
     return x.isalnum()

>>> seq=["af","12","^&*"]
>>> filter(funx,seq)
['af', '12']
>>> filter(lambda x: x.isalnum(),seq)
['af', '12']

第七章：更加抽象
类的命名空间
指定超类：

class Filter:
    def init(self):
        self.blocked=[]
    def filter(self,sequence):
        return [x for x in sequence if x not in self.blocked]   

class SpAFilter(Filter):
    def init(self):
        self.blocked=['SPAM']
>>> f=Filter()
>>> f.init()
>>> f.filter([1,2,3])
[1, 2, 3]
>>> s=SpAFilter()
>>> s.init()
>>> s.filter(['SPAM','asfd'])
['asfd']

调查继承
issubclass()
第八章：异常
import exceptions

BaseException
 +-- SystemExit
 +-- KeyboardInterrupt
 +-- GeneratorExit
 +-- Exception
      +-- StopIteration
      +-- StandardError
      |    +-- BufferError
      |    +-- ArithmeticError
      |    |    +-- FloatingPointError
      |    |    +-- OverflowError
      |    |    +-- ZeroDivisionError
      |    +-- AssertionError
      |    +-- AttributeError
      |    +-- EnvironmentError
      |    |    +-- IOError
      |    |    +-- OSError
      |    |         +-- WindowsError (Windows)
      |    |         +-- VMSError (VMS)
      |    +-- EOFError
      |    +-- ImportError
      |    +-- LookupError
      |    |    +-- IndexError
      |    |    +-- KeyError
      |    +-- MemoryError
      |    +-- NameError
      |    |    +-- UnboundLocalError
      |    +-- ReferenceError
      |    +-- RuntimeError
      |    |    +-- NotImplementedError
      |    +-- SyntaxError
      |    |    +-- IndentationError
      |    |         +-- TabError
      |    +-- SystemError
      |    +-- TypeError
      |    +-- ValueError
      |         +-- UnicodeError
      |              +-- UnicodeDecodeError
      |              +-- UnicodeEncodeError
      |              +-- UnicodeTranslateError
      +-- Warning
           +-- DeprecationWarning
           +-- PendingDeprecationWarning
           +-- RuntimeWarning
           +-- SyntaxWarning
           +-- UserWarning
           +-- FutureWarning
           +-- ImportWarning
           +-- UnicodeWarning
           +-- BytesWarning

自定义异常类
没有参数

class muffledCalculator:
    muffled=False
    def calc(self,expr):
        try:
            return eval(expr)
        except ZeroDivisionError:
            if self.muffled:
                print 'Division by zero is illegal'
            else:
                raise

用一个块捕捉多个异常
捕捉对象；

try:
    x=input('Enter the 1st number:')
    y=input('Enter the 2nd number:')
    print x/y
except(ZeroDivisionError,TypeError),e:
    print e

try:
     except:
     else:
finally:

异常之禅？
第九章：魔法方法、属性和迭代器
构造函数
绑定超类：

class Bird:
    def __init__(self):
        self.hungry=True
    def eat(self):
        if self.hungry:
            print 'aaa'
            self.hungry=False
        else:
            print 'No thanks'

class SongBird(Bird):
    def __init__(self):
        Bird.__init__(self)
        self.sound='Squawk'
    def sing(self):
        print self.sound

使用super函数

__metaclass__=type
class Bird:
    def __init__(self):
        self.hungry=True
    def eat(self):
        if self.hungry:
            print 'aaa'
            self.hungry=False
        else:
            print 'No thanks'

class SongBird(Bird):
    def __init__(self):
       # Bird.__init__(self)
        super(SongBird,self).__init__()
        self.sound='Squawk'
    def sing(self):
        print self.sound

成员访问
基本的序列和映射规则
__len__(self)
__getitem__(self,key)
__setitem__(self,key)
__delitem__(self,key)

def checkIndex(key):
    if not isinstance(key,(int,long)):raise TypeError
    if key<0:raise IndexError

class ArithmeticSequence:
    def __init__(self,start=0,step=1):
        self.start=start
        self.step=step
        self.changed={}
    def __getitem__(self,key):
        checkIndex(key)

        try:return self.changed[key]
        except KeyError:
            return self.start+key*self.step
    def __setitem__(self,key,value):
        checkIndex(key)
        self.changed[key]=value
    def __delitem__(self,key):
        checkIndex(key)
        del self.changed[key]

子类化列表，字典和字符串
标准库里有3个关于序列和映射规则（UserList,UserString,UserDict）

class CounterList(list):
    def __init__(self,*args):
        super(CounterList,self).__init__(*args)
        self.counter=0
    def __getitem__(self,index):
        self.counter+=1
        return super(CounterList,self).__getitem__(index)

property函数
property()其实不是一个真正的函数，它是拥有许多特殊方法的类，也正是这个方法完成了所有的工作。

__metaclass__=type
class Rectangle:
    def __init__(self):
        self.width=0
        self.height=0
    def setSize(self,size):
        self.width,self.height=size
    def getSize(self):
        return self.width,self.height
    size=property(getSize,setSize)

使用__getattr__ ___setattr__

__metaclass__=type
class Rectangle:
    def __init__(self):
        self.width=0
        self.height=0
    def __setattr__(self,name,value):
        if name=='size':
            self.width,self.height=value
        else:
            self.__dict__[name]=value
    def __getattr__(self,name):
        if name=='size':
            return self.width,self.height
        else:
            raise AttributeError

迭代器

class Fibs:
    def __init__(self):
        self.a=0
        self.b=1
    def next(self):
        self.a,self.b=self.b,self.a+self.b
        return self.a
    def __iter__(self):
        return self

>>> fibs=Fibs()
>>> for f in fibs:
     if f>1000:
          print f
          break
    
1597
>>> it=iter([1,2,4])
>>> it.next()
1
>>> it.next()
2

生成器

def flatten(nested):
    for sublist in nested:
        for element in sublist:
            yield element

递归

def flatten(nested):
    try:
        for sublist in nested:
            for element in flatten(sublist):
                yield element
    except TypeError:
        yield nested

生成器由两部分组成：生成器的函数和生成器的迭代器

不适用yield的模拟生成器

def flatten(nested):
    result=[]
    try:
        try:nested+''
        except TypeError:pass
        else: raise TypeError
        for sublist in nested:
            for element in flatten(sublist):
                result.append(element)
    except TypeError:
        result.append(nested)
    return result

八皇后问题解决

def conflict(state,nextX):
    nextY=len(state)
    for i in range(nextY):
        if abs(state[i]-nextX)in(0,nextY-i):
            return True
    return False

def queens(num=8,state=()):
        for pos in range(num):
            if not conflict(state,pos):
                if len(state)==num-1:
                    yield(pos,)
                else:
                    for result in queens(num,state+(pos,)):
                        yield(pos,)+result

def prettyprint(solution):
    def line(pos,length=len(solution)):
        return '.'*(pos)+'X'+'.'*(length-pos-1)
    for pos in solution:
        print line(pos)

>>> import random
>>> prettyprint(random.choice(list(queens(8))))

第十章：模块

>>> import sys,pprint
>>> pprint.pprint(sys.path)

探究模块
自定义模块

>>> import sys
>>> sys.path.append('E:')
>>> import hello2
>>> hello2.hello()
Hello,world
>>> import sys,pprint
>>> pprint.pprint(sys.path)

>>> import copy
>>> [n for n in dir(copy) if not n.startswith('_')]
['Error', 'PyStringMap', 'copy', 'deepcopy', 'dispatch_table', 'error', 'name', 't', 'weakref']

sys模块
argv
exit
modules
path
platform
stdin
stdout
stderr
os模块

fileinput模块

import fileinput

for line in fileinput.input(inplace=True):
    line=line.rstrip()
    num=fileinput.lineno()
    print '%-40s#%2i'% (line,num)

集合、堆、双端队列
堆

>>> set(range(10))
set([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])

Instances of Set and ImmutableSet both provide the following operations:

Operation	Equivalent	Result
len(s)		cardinality of set s
x in s		test x for membership ins
x not in s		test x for non-membership ins
s.issubset(t)	s <= t	test whether every element in s is in t
s.issuperset(t)	s >= t	test whether every element in t is in s
s.union(t)	s | t	new set with elements from both s and t
s.intersection(t)	s & t	new set with elements common to s and t
s.difference(t)	s - t	new set with elements in s but not int
s.symmetric_difference(t)	s ^ t	new set with elements in either s or t but not both
s.copy()		new set with a shallow copy of s

堆
heapq.heappush ( heap,item )
Push the value item onto theheap, maintaining the heap invariant.
heapq.heappop ( heap )
Pop and return the smallest item from theheap, maintaining the heap invariant. If the heap is empty, IndexError is raised.
heapq.heappushpop ( heap,item )
Push item on the heap, then pop and return the smallest item from theheap. The combined action runs more efficiently than heappush() followed by a separate call to heappop() .
New in version 2.6.
heapq.heapify ( x )
Transform list x into a heap, in-place, in linear time.
heapq.heapreplace ( heap,item )
Pop and return the smallest item from theheap, and also push the newitem. The heap size doesn’t change. If the heap is empty, IndexError is raised.

>>> from heapq import *
>>> from random import shuffle
>>> data=range(10)
>>> shuffle(data)
>>> heap=[]
>>> for n in data:
     heappush(heap,n)

双端队列

>>> from collections import deque
>>> q=deque(range(5))
>>> q
deque([0, 1, 2, 3, 4])
>>> q.append(9)
>>> q
deque([0, 1, 2, 3, 4, 9])
>>> q.appendleft(6)
>>> q
deque([6, 0, 1, 2, 3, 4, 9])
>>> q.pop()
9
>>> q
deque([6, 0, 1, 2, 3, 4])

time模板
random模板
shelve模板

import sys,shelve

def store_person(db):
    pid=raw_input('Enter ID:')
    person={}
    person['name']=raw_input('Name:')
    person['age']=raw_input('Age:')
    person['phone']=raw_input('Phone')
    db[pid]=person
   
def lookup_person(db):
    pid=raw_input('Enter ID:')
    field=raw_input('what would you like to know?(name,age,phone)')
    field=field.strip().lower()
    print field.capitalize()+':',db[pid][field]
def print_help():
    print 'commads:'
    print 'store'
    print 'lookup'
    print 'quit'
    print '?'
def enter_command():
    cmd=raw_input('Enter Command?')
    cmd=cmd.strip().lower()
    return cmd
def main():
    database=shelve.open('E:\\database.dat')
    try:
        while True:
            cmd=enter_command()
            if cmd=='store':
                store_person(database)
            if cmd=='lookup':
                lookup_person(database)
            if cmd=='?':
                print_help()
            elif cmd=='quit':
                return
    finally:
        database.close()

if __name__=='__main__':main()

re模块
complie()
search()
match()
split()
findall()
sub()
escape()

>>> m=re.match(r'www\.(.*)\..{3}','www.python.org')
>>> m.group(1)

>>> re.split('[.]+',text,maxsplit=2)
['alpha,beta,gamma,,, delta']

模板系统示例

第十一章：文件与素材

def process(string):
    print 'Processing:',string
   
f=open(r'E:/hello.py')

char=f.read(1)
while True:
   # process(char)
    #char=f.read(1)
   line=f.readline()
   if not line:break
   process(line)
f.close()

第十二章：图形界面
下载安装wxpython
第十三章：数据库支持
SQLite PySQLite
第十四章：网络编程
socket模块
urllib和urllib2模块

SocketServer模块
客户端:

from socket import *

host='127.0.0.1'
port=3130
bufsize=1024
addr=(host,port)

client=socket(AF_INET,SOCK_STREAM)
client.connect(addr)


while True:
    data=raw_input()
    if not data or data =='exit':
        break
    client.send('%s\r\n' % data)
    data=client.recv(bufsize)
    if not data:
        break
    print data.strip()

client.close()

服务器端：

import SocketServer
from SocketServer import StreamRequestHandler as SRH
from time import ctime

host='127.0.0.1'
port=3130
addr=(host,port)

class Servers(SRH):
    def handle(self):
        print 'get connection from',self.client_address
        self.wfile.write('connection %s:%s at %s succeed!'%(host,port,ctime))
        while True:
            data=self.request.recv(1024)
            if not data:break
            print data
            print 'server is running ...'


server=SocketServer.ThreadingTCPServer(addr,Servers)
server.serve_forever()

多连接
有3种方法可以实现这个目的：分叉、线程、以及异步I/O。

带有select和poll的异步I/O

Twisted网络框架

第十五章：python和万维网
屏幕抓取、CGI和mod_python

第十六章：测试
doctest

doctest

def square(x):
    '''
square a number
'''
    return x*x

if __name__='__main__':
    import doctest,

unitest模板

import unittest,my_math

class ProductTestCase(unittest.TestCase):
    def testIntegers(self):
        for x in xrange(-10,10):
            for y in xrange(-10,10):
                p=my_math.product(x,y)
                self.failUnless(p==x*y,'Interger failed')

    def testFloats(self):
        for x in xrange(-10,10):
            for y in xrange(-10,10):
                x=x/10.0
                y=y/10.0
                p=my_math.product(x,y)
            self.failUnless(p==x*y,'Failed')

if __name__=='__main__':
    unittest.main()

使用PyChecker和PyLint检查源代码
第十七章：扩展python
使用Jython和IronPython
使用CPython
SWIG

第十八章：程序打包

Distutils基础

第十九章：好玩的编程

原型设计
配置文件
日志记录