Python初步

# -*- coding: utf-8 -*
# -*- coding: cp936 -*-

# 检验编码格式
import sys
print(sys.stdout.encoding)

# 字符串
print "hello world"
print "my name is %s" %"dongshihong"
name="dongshihong"
print "my name is %s"%(name)
print "my name is",name
print len("hello")

a="AbcDefg"
print a[2:5]
print a
print a.lower()




# 函数
def print_name(name):
    print "your name is ",name
    return ("%s is good studt" %name)

print print_name("zhangsan")
print "==================="
print print_name("lisi")


# 常用的数据结构

# java中的数据结构：hashmap array  set
# python中与java的对比： 
# hashmap->dict(字典)->{}
# array->list->[]
# set->set->set()


# dict
color={"red":0.2,"green":0.4,"blue":0.4}
print color
print color["red"]


# list
color_list=["red","green","yellow","green"]
print color_list
print color_list[0]

#set (内部不能有相同的元素出现)
a_set=set()
a_set.add("111")
a_set.add("222")
print a_set


# 条件判断语句
# if

a=1

if a>0: 
    print "a gt 0"
elif a==0:
    print "a eq 0"
else:
    print "a lt 0"



# for

for value in xrange(1,10):
    print value


a=0
for value in xrange(1,10):
    a+=value
print a


缩进的测试
a=0
for value in xrange(1,10):
 a= value+a
 print a






a_list=[]
a_list.append("111")
a_list.append("333")
a_list.append("222")
a_list.append("444")

for value in a_list:
    print value



b_dic={}
b_dic["aaa"]=1
b_dic["bbb"]=2
b_dic["ccc"]=3
b_dic["ddd"]=4
b_dic["eee"]=5


for key ,value in b_dic.items():
    print key,value


for key ,value in b_dic.items():
    print key+"====>"+str(value)

c_set=set()
c_set.add("aaa")
c_set.add("bbb")
c_set.add("ccc")
c_set.add("ddd")
c_set.add("eee")

for value in c_set:
    print value





while
count =2
while count>0:
    print "i love python"
    count-=1


i=0
while i<10:
    i+=1
    if i % 2 > 0:
        continue
    print i




# 异常的处理

try:
    a=6
    b=a/0
except Exception as e:
    print Exception ,":", e
else:
    pass
finally:
    pass


try:
    print "1111111"
    fh=open('testFile.txt','r')
    print "2222222"
except IOError as e:
    print "3333333"
else:
    print "4444444"
    fh.close()
finally:
    pass


# 算法

import math


# 求2的3次方
print math.pow(2,3)
print math.floor(4.9)
print round(4.9)


#随机数
import random

items=[1,2,3,4,5,6]
random.shuffle(items)
print items

a=random.randint(1,10)
print a

s_list=random.sample("afdasfafa",2)
print s_list