一、input(...)和raw_input(...)
#简单的差看帮助文档input(...)和raw_input(...)有如下区别 >>> help(input) help on built-in function input in module __builtin__: input(...) input([prompt]) -> value equivalent to eval(raw_input(prompt)). >>> help(raw_input) help on built-in function raw_input in module __builtin__: raw_input(...) raw_input([prompt]) -> string read a string from standard input. the trailing newline is stripped. if the user hits eof (unix: ctl-d, windows: ctl-z+return), raise eoferror. on unix, gnu readline is used if enabled. the prompt string, if given, is printed without a trailing newline before reading. #可见 input会根据输入的内容eval结果来返回值，即输入纯数字，则得到的就是纯数字 # raw_input返回的才是字符串 #test： >>> a = input(输入数字) 输入数字1 >>> type(a) >>> b=raw_input(输入数字) 输入数字1 >>> type(b)
ps:在python3.0以后的版本中,raw_input和input合体了,取消raw_input,并用input代替,所以现在的版本input接收的是字符串
二、python三目运算符
虽然python没有c++的三目运算符(?:)，但也有类似的替代方案，
那就是
1、 true_part if condition else false_part
>>> 1 if true else 0 1 >>> 1 if false else 0 0 >>> true if true else false 'true' >>> true if true else false 'falser'
2、 (condition and [true_part] or [false_part] )[0]
>>> (true and [true] or [false])[0] 'true' >>> (false and [true] or [false])[0] 'false' >>>
三、获得指定字符串在整个字符串中出现第n次的索引
# -*- coding: cp936 -*- def findstr(string, substr, findcnt): liststr = a.split(substr,findcnt) if len(liststr) >> #14 #-1
四、enumerate用法：
遍历序列的时候，可能同时需要用到序列的索引和对应的值，这时候可以采用enumerate方法进行遍历
enumerate的说明如下：
>>> help(enumerate) help on class enumerate in module __builtin__: class enumerate(object) | enumerate(iterable[, start]) -> iterator for index, value of iterable | | return an enumerate object. iterable must be another object that supports | iteration. the enumerate object yields pairs containing a count (from | start, which defaults to zero) and a value yielded by the iterable argument. | enumerate is useful for obtaining an indexed list: | (0, seq[0]), (1, seq[1]), (2, seq[2]), ... | | methods defined here: | | __getattribute__(...) | x.__getattribute__('name') x.name | | __iter__(...) | x.__iter__() iter(x) | | next(...) | x.next() -> the next value, or raise stopiteration | | ---------------------------------------------------------------------- | data and other attributes defined here: | | __new__ = | t.__new__(s, ...) -> a new object with type s, a subtype of t
五、遍历序列的方法
>>> list = ['a','b','c'] >>> for index, value in enumerate(list): print index, value 0 a 1 b 2 c >>>
六、使用python random模块的sample函数从列表中随机选择一组元素
import list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] slice = random.sample(list, 5)#从list中随机获取5个元素，作为一个片断返回 print slice print list #原有序列并没有改变。
七、用json打印包含中文的列表字典等
# -*- coding:utf-8 -*- import json #你的列表 lista = [{'path': ['[aws] \xe7\xbe\x8e\xe5\xb0\x91\xe5\xa5\xb3\xe6\x88\x98\xe5\xa3\xab sailor moon crystal - moon pride mv[big5][bdrip 1080p x264 aac][6e5cfe86].mp4'], 'length': 131248608l}, {'path': ['[aws] \xe7\xbe\x8e\xe5\xb0\x91\xe5\xa5\xb3\xe6\x88\x98\xe5\xa3\xab sailor moon crystal - moon pride mv[big5][bdrip 720p x264 aac][639d304a].mp4'], 'length': 103166306l}, {'path': ['[aws] \xe7\xbe\x8e\xe5\xb0\x91\xe5\xa5\xb3\xe6\x88\x98\xe5\xa3\xab sailor moon crystal - moon pride mv[big5][bdrip 480p x264 aac][5a81baca].mp4'], 'length': 75198408l}]#打印列表print json.dumps(lista, encoding='utf-8', ensure_ascii=false)
输出结果：
>>> [{path: [[aws] 美少女战士 sailor moon crystal - moon pride mv[big5][bdrip 1080p x264 aac][6e5cfe86].mp4], length: 131248608}, {path: [[aws] 美少女战士 sailor moon crystal - moon pride mv[big5][bdrip 720p x264 aac][639d304a].mp4], length: 103166306}, {path: [[aws] 美少女战士 sailor moon crystal - moon pride mv[big5][bdrip 480p x264 aac][5a81baca].mp4], length: 75198408}]
希望本文所述对大家的python程序设计有所帮助。