1 from 模块 import 函数
2 >>> from math import sin
3 >>> sin(1.5)
4 0.9974949866040544
5
6 直接import
7 >>> import cmath
8 >>> cmath.sqrt(-9)
9 3j
10
11 字符串表示，str和repr
12 >>> print 100000L
13 100000
14 >>> print (10000L)
15 10000
16 >>> print ("1000L")
17 1000L
18 >>> print repr("Hello world!") repr:创建一个字符串，以合法的Python表达式的形式来表示值。
19 'Hello world!'
20 >>> print repr(10000L)
21 10000L
22 >>> print str("Hello") str:把值转换为合理形式的字符串，以便用户理解
23 Hello
24 >>> print str(1000L)
25 1000
26 (Plus 反引号`: used in 2.7 deprecated.)
27
28 raw_input: 把所有的输入当做原始数据，放入字符串中
29
30 长字符串: 三个引号 or \[回车]
31
32 print r's\tring' 输入原始字符串。不能以'\'结尾(显而易见)
33
34 print u"unicode string" 2.7以后不支持？
35
36 序列：
37
38 1 索引：
39 >>> week = ['Mon', 'Tue'] + 3 * ['Wed']
40 >>> week
41 ['Mon', 'Tue', 'Wed', 'Wed', 'Wed']
42 >>> week[1]
43 'Tue'
44
45 2 分片：
46 >>> week[1:3]
47 ['Tue', 'Wed']
48 >>> week[1:2]
49 ['Tue']
50 >>> week[-3:]
51 ['Wed', 'Wed', 'Wed']
52
53 3 步长
54 >>> num = [1,2,3,4,5,6,7,8,9]
55 >>> num[1:7:2]
56 [2, 4, 6]
57 >>> num[7:1:-2]
58 [8, 6, 4]
59
60 空值 None
61
62 布尔值 True False
63
64 成员资格 in
65 >>> array = [1,2,3]
66 >>> 1 in array
67 True
68 >>> 4 in array
69 False
70
71 长度、最大值和最小值 len max min
72
73 列表：
74 list函数 返回列表
75 >>> array=[1,2,3,4,5]
76 >>> list(array)
77 [1, 2, 3, 4, 5]
78
79 del array[1] 删除元素
80 分片赋值 and so on.
81
82 列表方法：
83 append(element)
84 count(element)
85 extend(lsit)
86 index(element)
87 isert(index, element)
88 pop() & pop(index)
89 remove(element)
90 reverse()
91 sort()
92 cmp(element, element)
93
94
95 元组：
96 >>> (1, 2, 3)
97 (1, 2, 3)
98 >>> (1,)
99 (1,)
100 >>> (1)
101 1
102
103 tuple函数：返回元组
104 >>> tuple([1, 2, 3])
105 (1, 2, 3)
106 >>> tuple('yes')
107 ('y', 'e', 's')
108
109 字符串
110 格式化输出
111 方法：
112 find rfind index rindex count startwith endwith
113 join split(element) splitlines
114 lower islower capitalize swapcase title istitile upper isupper
115 replace(a, b)
116 strip() strip(element)
117
118 >>> import string
119 >>> table = string.maketrans('ex', 'ez')
120 >>> len(table)
121 256
122 >>> table[97: 123]
123 'abcdefghijklmnopqrstuvwzyz'
124 >>> 'index fix fex'.translate(table)
125 'indez fiz fez'
126
127 字典：
128 >>> stu = {'tom': '026', 'van': '027', 'von': '028', 'Liang': '029'}
129 >>> stu
130 {'von': '028', 'van': '027', 'Liang': '029', 'tom': '026'}
131 >>> stu['von']
132 '028'
133 >>> stu = [('tom', '1'), ('jim', '2')]
134 >>> stu
135 [('tom', '1'), ('jim', '2')]
136 >>> d = dict(stu)
137 >>> d
138 {'jim': '2', 'tom': '1'}
139 >>> d['jim']
140 '2'
141 >>> d = dict(name = 'tom', age = '23')
142 >>> d
143 {'age': '23', 'name': 'tom'}
144
145 键可以为任何不可变类型
146
147 >>> x = [None] * 5
148 >>> x
149 [None, None, None, None, None]
150
151 >>> x = {}
152 >>> x
153 {}
154 >>> x['q'] = 123
155 >>> x
156 {'q': 123}
157
158 字典的格式化字符串：
159 >>> phone = {'tom': '110', 'jim': '120'}
160 >>> 'tom\'s phone number is %(tom)s' % phone
161 "tom's phone number is 110"
162
163 字典方法
164 clear
165 copy 浅复制； deepcopy 深复制
166 fromkeys([key1, key2]) 使用给定的键建立新的字典，键值为None.
167 get(key, default value)
168 has_key(key)
169 items() 以列表方式返回item
170 iteritems() 返回迭代器对象（高效）
171 keys() 以列表方式返回键
172 iterkeys() 以迭代器方式返回
173 pop(key) 返回键的值并移除键值对
174 popitem() 弹出随机项
175 setdefault(key, default value) ≈ get + 在字典中不含有给定键的情况下设定相应的键值
176 update(dict) 用一个字典项更新另外一个字典
177 values()
178 itervalues()
179
180 print
181 在3.0前为语句，3.0后为函数
182
183 导入模块、方法
184 import somemodule
185 from somemodule import somefuction1, ...
186 from somemodule import *
187 import somemodule as alias
188 from somemodule import somefuction as alias
189
190 序列解包
191 >>> x, y, z = 1, 2, 3
192 >>> print x, y, z
193 1 2 3
194 >>> value = 1, 2, 3
195 >>> value
196 (1, 2, 3)
197 >>> print value
198 (1, 2, 3)
199 >>> x, y = y, z
200 >>> x, y, z
201 (2, 3, 3)
202 >>> d = {'tom': 1, 'jim': 2}
203 >>> key, value = d.popitem()
204 >>> key, value
205 ('jim', 2)
206 >>> key
207 'jim'
208 >>> value
209 2
210
211 链式赋值
212 x = y = ...
213
214 增量赋值
215 >>> x = 't'
216 >>> x += 'om'
217 >>> x
218 'tom'
219 >>> x *= 2
220 >>> x
221 'tomtom'
222
223 if语句
224 if(clause):
225 ...
226 ...
227 elif(clause):
228 ...
229 ...
230 else:
231 ...
232 ...
233
234 is
235 同一性运算符
236
237 in
238 成员资格运算符
239
240 and or not
241 布尔运算符
242 Special
243 >>> name = raw_input("Name: ") or '<unknown>'
244 Name:
245 >>> name
246 '<unknown>'
247 >>> name = raw_input("Name: ") or '<unknown>'
248 Name: Tom
249 >>> name
250 'Tom'
251 三元运算
252 a if b else c
253
254 >>> b = 1
255 >>> a = 'true' if (b == 1) else 'false'
256 >>> a
257 'true'
258 >>> b = 0
259 >>> a = 'true' if (b == 1) else 'false'
260 >>> a
261 'false'
262
263 assert 断言
264 >>> a = 1
265 >>> assert a == 2, 'a should equals 2'
266
267 Traceback (most recent call last):
268 File "<pyshell#13>", line 1, in <module>
269 assert a == 2, 'a should equals 2'
270 AssertionError: a should equals 2
271
272 while语句
273 >>> x = 1
274 >>> while x < 10:
275 print x
276 x += 1
277
278 range() 范围函数
279 >>> range(10)
280 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
281 >>> range(0, 10)
282 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
283
284 for 语句
285 nums = [1, 2, 3]
286 for num in nums:
287 print num
288
289 for x in range(0, 3):
290 print x
291
292 遍历字典元素：
293 >>> d = {'a': 'tom', 'b': 'jim'}
294 >>> for key in d:
295 print key, ":", d[key]
296 a : tom
297 b : jim
298 >>> for key, value in d.items():
299 print key, ":", value
300 a : tom
301 b : jim
302
303 并行迭代：
304 >>> name = ['tom', 'jim']
305 >>> age = [18, 20]
306 >>> for i in range(len(name)):
307 print name[i], ":", age[i]
308 tom : 18
309 jim : 20
310 >>> for n, a in zip(name, age):
311 print n, ":", a
312 tom : 18
313 jim : 20
314
315 zip函数可用于不等长的序列
316
317 编号迭代：
318 >>> s = ['xxx', 'yyy', 'xdresxxx']
319 >>> for index, string in enumerate(s):
320 if('xxx' in string):
321 s[index] = '@@@'
322 >>> s
323 ['@@@', 'yyy', '@@@']
324
325 sorted、reversed、join函数
326
327 break、continue语句
328
329 pass语句
330
331 del 删除名称 not 值
332
333 exec 执行字符串的语句
334 命名空间/作用域
335 >>> from math import sqrt
336 >>> scope = {}
337 >>> exec 'sqrt = 1' in scope
338 >>> sqrt(4)
339 2.0
340 >>> scope['sqrt']
341 1
342
343 eval 计算Python表达式
344 >>> eval(raw_input("Expression: "))
345 Expression: 2 + 3 - 4 *5
346 -15
347 >>> raw_input("Expression: ")
348 Expression: 1 + 1
349 '1 + 1'
350
351 >>> scope = {}
352 >>> exec 'x = 2' in scope
353 >>> eval ('x * x', scope)
354 4
355
356 callable 判断函数是否可以调用（3.0不可用）
357
358 创建函数
359 >>> def hello(name):
360 return 'Hello ' + name
361 >>> hello('tom')
362 'Hello tom'
363
364 记录函数
365 >>> def plus(a, b):
366 'Return a + b'
367 return a + b
368 >>> plus.__doc__
369 'Return a + b'
370
371 >>> help(plus)
372 Help on function plus in module __main__:
373 plus(a, b)
374 Return a + b
375
376 关键字参数
377 plus(a = xxx, b = yyy) 等于 plua(b == yyy, a = xxx)
378
379 在函数给参数提供默认值：
380 >>> def demo(greeting = 'Hello!'):
381 print greeting
382 >>> demo()
383 Hello!
384 >>> demo('你好')
385 你好
386
387 收集参数
388 >>> def say_hello(greeting, *names, **extras):
389 print greeting, names, extras
390 >>> say_hello('Hi', 'tom', 'jim', 'lara', x = 'glad', y = 'to see you.')
391 Hi ('tom', 'jim', 'lara') {'y': 'to see you.', 'x': 'glad'}
392
393 逆转过程（分割）
394 >>> def hi(hi, you):
395 print hi, you
396 >>> hello = ('Hello', 'Tom')
397 >>> hi(*hello)
398 Hello Tom
399
400 >>> yeah = {'hi': 'Hello, ', 'you': 'Tom'}
401 >>> hi(**yeah)
402 Hello, Tom
403
404 作用域
405 vars()：返回变量字典
406 >>> x = 1
407 >>> scope = vars()
408 >>> scope['x']
409 1
410 >>> scope['x'] += 1
411 >>> scope['x']
412 2
413 globals()：返回全局变量的字典
414 locals()：返回局部变量的字典
415 global关键字：声明变量为全局变量
416 >>> x
417 3
418 >>> def change_x():
419 global x
420 x += 1
421 return x
422 >>> change_x()
423 4
424 >>>
425
426 嵌套函数
427 >>> def multiply(a):
428 def multiplyByFactor(b):
429 return a * b
430 return multiplyByFactor
431 >>> num = multiply(2)
432 >>> num
433 <function multiplyByFactor at 0x0000000002B79C18>
434 >>> num(3)
435 6
436 >>> num(4)
437 8
438 >>> multiply(4)(5)
439 20
440
441 类：
442 调查继承：
443 issubclass(subclass, baseclass)
444 subclass.__bases__
445
446 判断类的实例：
447 isinstance(instance, class)
448
449 对象所属类：
450 object.__class__
451
452 多继承：
453 def class X (class1, class2)
454
455 hasattr(object, '<attr name>')
456
457 getattr(object, '<attr name>', <default value>)
458
459 setattr(object, '<attr name>', <value>)
460
461 object.__dict__ 查看对象内所有存储的值
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