【Python】基础练习题-1

#练习1：从键盘输入两个数，并比较其大小，直到输入e/E退出程序

while 1:

    input_number=raw_inut("please input two numbers,enter "e" or "E" to exit:")

    try:

        if input_number.isdigit():

            lst=[]

            lst_new=lst.append(input_number)

            if lst_new[0]>lst_new[1]:

                print "%s大于%s",%(lst_new[0],lst_new[1])

            elif st_new[0]<lst_new[1]:

                print "%s小于%s",%(lst_new[0],lst_new[1])

            else:

                print "%s等于%s",%(lst_new[0],lst_new[1])

        else:

            raise TypeError

        if input_number=="e" or input_number=="E":

            break

    except TypeError:

        print "input is not a number,try again"

#练习2：将列表元素交替地作为建和值来创建字典

lst=[1:"a",2:"b",3:"c"]

dicts={}

for i in range(0,len(lst),2):

    dicts[lst[i]]=lst[i+1]

print dicts

#练习3：分别输出字符串中奇数坐标和偶数坐标的字符

num=["a","b","c","d",1,2,3,4]

oddindex_number=[]

evenindex_number=[]

for i in range(0,len(str)):

    if i%2!=0:

        oddindex_number.append(num[i])

    else:

        evenindex_number.append(num[i])

print "奇数坐标的字符为：",oddindex_number

print "偶数坐标的字符为：",evenindex_number

#练习4：将一个字典的 key和value 互换

dicts={1:4,2:5,3:6}

new_dicts={}

for k,v in dicts.items():

    if isinstance(v,(str,float,tuple,int,complex)):

    #print k,v

        new_dicts[v]=k

    else:

        print u"value %s不可哈希" %v

print new_dicts

#这是个递归的一个例子

def fib(num):

    result=[0,1]

    for i in range(num-2):

        result.append(result[-2]+result[-1])

   return result

ptint fib(10)