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下面列出的都是这些年总结的Python的有用的知识点和一些工具。希望对你有所帮助！
交换变量值
x = 6 y = 5 x, y = y, x print x >>> 5 print y >>> 6
内联if语句
print "Hello" if True else "World" >>> Hello
联接
nfc = ["Packers", "49ers"] afc = ["Ravens", "Patriots"] print nfc + afc >>> [‘Packers‘, ‘49ers‘, ‘Ravens‘, ‘Patriots‘] print str(1) + " world" >>> 1 world print `1` + " world" >>> 1 world print 1, "world" >>> 1 world print nfc, 1 >>> [‘Packers‘, ‘49ers‘] 1
数字运算
#Floor Division (rounds down) print 5.0//2 >>> 2 #2 raised to the 5th power print 2**5 >> 32
注意float数做整除运算后的出来的还是整数
print .3/.1 >>> 2.9999999999999996 print .3//.1 >>> 2.0
数字对比
x = 2 if 3 > x > 1: print x >>> 2 if 1 < x > 0: print x >>> 2
同时遍历两个数组
nfc = ["Packers", "49ers"] afc = ["Ravens", "Patriots"] for teama, teamb in zip(nfc, afc): print teama + " vs. " + teamb >>> Packers vs. Ravens >>> 49ers vs. Patriots
延伸阅读zip方法，请点这里。
遍历List并获得index
teams = ["Packers", "49ers", "Ravens", "Patriots"] for index, team in enumerate(teams): print index, team >>> 0 Packers >>> 1 49ers >>> 2 Ravens >>> 3 Patriots
理解List
这个：
numbers = [1,2,3,4,5,6] even = [] for number in numbers: if number%2 == 0: even.append(number)
可以写成：
numbers = [1,2,3,4,5,6] even = [number for number in numbers if number%2 == 0]
理解Dictionary
和List很相似，Dictionary的这个可以写成：
teams = ["Packers", "49ers", "Ravens", "Patriots"] print {key: value for value, key in enumerate(teams)} >>> {‘49ers‘: 1, ‘Ravens‘: 2, ‘Patriots‘: 3, ‘Packers‘: 0}
初始化List的值
items = [0]*3 print items >>> [0,0,0]
List转换为String
teams = ["Packers", "49ers", "Ravens", "Patriots"] print ", ".join(teams) >>> ‘Packers, 49ers, Ravens, Patriots‘
从Dictionary中取得Item
一般来说是这样的，用一个try-except块包裹起来以防要取得的key值不存在：
data = {‘user‘: 1, ‘name‘: ‘Max‘, ‘three‘: 4}
try:
is_admin = data[‘admin‘]
except KeyError:
is_admin = False
但是你可以这样：
data = {‘user‘: 1, ‘name‘: ‘Max‘, ‘three‘: 4}
is_admin = data.get(‘admin‘, False)
取List得子集
很简单的取子集的方法：
x = [1,2,3,4,5,6] #First 3 print x[:3] >>> [1,2,3] #Middle 4 print x[1:5] >>> [2,3,4,5] #Last 3 print x[-3:] >>> [4,5,6] #Odd numbers print x[::2] >>> [1,3,5] #Even numbers print x[1::2] >>> [2,4,6]
60个字符搞定FizzBuzz问题
FizzBuzz问题：写一个程序打印1到100的数字。遇到3的倍数打印“Fizz”来替换这个数。5的倍数打印“Buzz“，对于既是3的倍数又是5的倍数的数字打印“FizzBuzz”代替这个数字
for x in range(1,101):print"Fizz"[x%3*4:]+"Buzz"[x%5*4:]or x
这里就是List的一个知识点了。如果方括号里，冒号左边的数字式大于字符串长度的，那么什么都不会输出！也就是在非3或者5的倍数的时候什么都不会输出。
集合
在collections模块下的Counter，有时候也是很有用的。
from collections import Counter print Counter("hello") >>> Counter({‘l‘: 2, ‘h‘: 1, ‘e‘: 1, ‘o‘: 1})
Itertools
from itertools import combinations teams = ["Packers", "49ers", "Ravens", "Patriots"] for game in combinations(teams, 2): print game >>> (‘Packers‘, ‘49ers‘) >>> (‘Packers‘, ‘Ravens‘) >>> (‘Packers‘, ‘Patriots‘) >>> (‘49ers‘, ‘Ravens‘) >>> (‘49ers‘, ‘Patriots‘) >>> (‘Ravens‘, ‘Patriots‘)
False == True
在python里，True和False只不过是全局变量，所以：
False = True if False: print "Hello" else: print "World" >>> Hello
如果你发现什么有趣的东西欢迎在下面补齐！
from：http://www.maxburstein.com/blog/python-shortcuts-for-the-python-beginner/
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原文地址：http://blog.csdn.net/future_challenger/article/details/43861985
