读书笔记---Python绝对简明手册(个人认为Python是C++的最佳拍档)
http://wiki.woodpecker.org.cn/moin/PyAbsolutelyZipManual最新版
[*]PyAbsolutelyZipManual
Python 绝对简明手册 -- zsp007@gmail.com ::-- ZoomQuiet
[*] Py2.5 绝对简明手册
[*] 语法
[*] if
[*] for
[*] pass
[*] in
[*] 参数格式 **para
[*] Lambda函数
[*] List的函数
[*] 列表推导式
[*] del
[*] 元组
[*] set
[*] zip
[*] reversed反向循环
[*] sorted排序
[*] sequence比大小
[*] 导入模块
[*] 包
[*] 格式化输出
[*] 等效代码
[*] 读写文件:
[*] pickle
[*] 初识类
[*] 类继承
[*] 多重继承
[*] Iterators 迭代器
[*] 生成器表达式
[*] 常用函数不完全手册
[*] 反馈
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1. Py2.5 绝对简明手册
简述
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PYthon绝对简明手册,初学必备!
[*]-- For Python2.5
版本:0.2 beta
作者:张沈鹏
参考:python2.5中文教程
感谢:Zoom.Quiet limodou
我的技术Blog 我的C++Blog 我的文学Blog
[*]-- 欢迎指出错误和遗漏,提出建议和意见,请发信到zsp007@gmail.com
1.1. 语法
1.1.1. if
<script type="text/javascript">
function isnumbered(obj) {return obj.childNodes.length && obj.firstChild.childNodes.length && obj.firstChild.firstChild.className == 'LineNumber';
}
function nformat(num,chrs,add) {var nlen = Math.max(0,chrs-(''+num).length), res = '';while (nlen>0) { res += ' '; nlen-- }return res+num+add;
}
function addnumber(did, nstart, nstep) {var c = document.getElementById(did), l = c.firstChild, n = 1;if (!isnumbered(c))if (typeof nstart == 'undefined') nstart = 1;if (typeof nstep== 'undefined') nstep = 1;n = nstart;while (l != null) {if (l.tagName == 'SPAN') {var s = document.createElement('SPAN');s.className = 'LineNumber's.appendChild(document.createTextNode(nformat(n,4,' ')));n += nstep;if (l.childNodes.length)l.insertBefore(s, l.firstChild)elsel.appendChild(s)}l = l.nextSibling;}return false;
}
function remnumber(did) {var c = document.getElementById(did), l = c.firstChild;if (isnumbered(c))while (l != null) {if (l.tagName == 'SPAN' && l.firstChild.className == 'LineNumber') l.removeChild(l.firstChild);l = l.nextSibling;}return false;
}
function togglenumber(did, nstart, nstep) {var c = document.getElementById(did);if (isnumbered(c)) {remnumber(did);} else {addnumber(did,nstart,nstep);}return false;
}
</script> <script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 x=int(raw_input("Please enter an integer:"))
2 if x<0:
3 print 'Negative Number'
4 elif x==0:
5 print 'Zero'
6 else:
7 print 'Positive Number'
1.1.2. for
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 a=['cat','door','example']
2 for x in a:
3 print x
#如果要修改a的内容，则用a的副本循环，如：
for x in a[:] :
.....................
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 >>>range(10,0,-3)
2
3 a=['cat','door','example']
4 for i in range(len(a)):
5 print i,a
break,continue 用法和C＋＋中类似
1.1.3. pass
while True:
pass #忽略，什么也不做
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 def fib(n=1000):#参数可以有默认值，多个可选参数赋值可以直接写"参数变量名＝值"来快速赋值
2 """这里给函数写文档注释"""
3 a,b=0,1
4 while b<n:
5 print b
6 a,b=b,a+b
#函数可以重命名,如
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 f=fib
2 f(223)
1.1.4. in
[*] <script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 if 'yes' in('y','ye','yes'):print'ok'
1.1.5. 参数格式 **para
#参数格式为 **para 表示接受一个字典,为 *para 表示接受一个元组
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 def test(para1,*args,**dic):
2 print para1
3 for arg in args : print arg
4 keys=dic.keys()
5 keys.sort()
6 for key in keys:print key ,':',dic
1.1.6. Lambda函数
[*] <script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 def make_incrementor(n):
2 return lambda x: x+n
3 f=make_incrementor(n)
4 >>>f(0)
5 42
6 >>>f(1)
7 43
1.1.7. List的函数
append(x) 追加到链尾
extend(L) 追加一个列表
insert(i,x) 在位置i插入x
remove(x) 删除第一个值为x的元素,如果不存在会抛出异常
pop() 返回并删除位置为i的元素,i未给定时默认作用在最后一个元素.表示i为可选的
index(x) 返回第一个值为x的元素,不存在则抛出异常
count(x) 返回x出现的次数
sort() 排序
reverse() 翻转,反转
filter(function函数 , sequence序列) 返回sequence中使filer为true的
map(function,sequence,) 返回新的sequence,序列中值为对每个元素分别调用function.
reduce(function,sequence,) 返回一个单值为,计算步骤为 :
[*]第1个结果=function(sequence,sequence)
[*]第2个结果=function(第1个结果,sequence)
[*]返回最后一个计算得值
[*]如果有init,则先调用
function(init,sequence) sequence只有一个元素时,返回该元素,为空时抛出异常.
1.1.8. 列表推导式
freshfruit=['banana',' loganberry']
>>>
['banana','loganberry']
vec=
>>>
>>>[(x,x**2) for x in vec] #一个元素一定要是一个sequence,而
是错误的
[(2,4),(4,16),(6,36)]
vec2=
+vec2 for i in range(len(vec))]
#str()是转换类型为可以打印的字符
1.1.9. del
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 a=
2 del a
3 >>>a
4
5 del a
6 >>>a
7
8 del a[:]
9 >>>a
10 []
11 del a
12 >>>a
抛出异常
1.1.10. 元组
t=1234,5567,'hello'
x,y,z=t #拆分操作可以应用于所有sequence
>>>x
1234
u=t,(1,2,3)
>>>u
((1234,5567,'hello'),(1,2,3))
empty=() #空元组
singleton='hi', #单个元素的元组
1.1.11. set
set（集合）：无序不重复的元素集
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 basket = ['apple','orange','apple','pear','apple','banana']
2 fruit=set(basket)
3 >>>fruit
4 set(['orange', 'pear', 'apple', 'banana'])
5 >>>'orange' in fruit
6 True
7 a=set('abracadabew')
8 >>>a
9 set(['a', 'c', 'b', 'e', 'd', 'r', 'w'])
10 b=set('wajgwaoihwb')
11 >>> b
12 set(['a', 'b', 'g', 'i', 'h', 'j', 'o', 'w'])
13 >>> a-b #差
14 set(['c', 'r', 'e', 'd'])
15 >>> a|b #并
16 set(['a', 'c', 'b', 'e', 'd', 'g', 'i', 'h', 'j', 'o', 'r', 'w'])
17 >>> a&b #交
18 set(['a', 'b', 'w'])
19 >>>a^b #(并-交)
20 set(['c', 'e', 'd', 'g', 'i', 'h', 'j', 'o', 'r'])
=== dict ===
字典:关键字为不可变类型,如字符串,整数,只包含不可变对象的元组.列表等不可以作为关键字.如果列表中存在关键字对,可以用dict()直接构造字典.而这样的列表对通常是由列表推导式生成的.
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 tel={'jack':4098,'sape':4139}
2 tel['guido']=4127
3 >>> tel
4 {'sape': 4139, 'jack': 4098, 'guido': 4127}
5 >>>tel['jack']
6 4098
7 del tel['sape']
8 >>>tel.keys()
9 ['jack', 'guido']
10 >>>tel.has_key('jack')
11 True
12 knight={'gallahad':'the pure','robin':'the brave'}
13 for k,v in knight.iteritems():
14 print k,v
输出:
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 gallahad the pure
2 robin the brave
enumerate()返回索引位置和对应的值
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 for i,v in enumerate(['tic','tac','toe'])
2 print i,v
输出:0 tic
1 tac
2 toe
1.1.12. zip
zip用于多个sequence的循环
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 questions=['name','quest','favorite color']
2 answers=['lancelot','the holy grail','blue']
3 for q,a in zip(questions,answers):
4 print 'What is your %s ? It is %s.'%(q,a)
输出:
What is your name ? It is lancelot.
What is your quest ? It is the holy grail.
What is your favorite color ? It is blue.
1.1.13. reversed反向循环
<script type="text/javascript">
document.write('Toggle line numbers<\/a>');
</script> Toggle line numbers
1 for i in reversed(range(1,4)):
2 print i
输出:
3
2
页:
[1]