python文件操作举例

发布时间：2019-08-22 08:00:37编辑：auto阅读（1247）

    1.把一个数字的list从小到大排序，然后写入文件，然后从文件中读取出来文件内容，然后反序，在追加到文件的下一行中

    import codecs

    def paixu(l):

       for i in xrange(0,len(l)-1):

           for j in xrange(0,len(l)-i-1):

               if l[j]>l[j+1]:

                   l[j],l[j+1] = l[j+1],l[j]

       return l

    if __name__ == "__main__":

       new_list= list(input("please input a list,like( 1,2,3): "))

       print ("oringin date: ")

       print (new_list)

       list1 = paixu(new_list)

       print ("sorted: " )

       print (list1)

       with codecs.open("paixu.txt","w") as file1:

           for i in list1:

               file1.write(str(i))

               file1.write("\n")

           file1.close()

       with codecs.open("paixu.txt","r") as file2:

           list2 = file2.readlines()

           print("read data: ")

           print(list2)

           file2.close()

       with codecs.open("paixu.txt","a") as file3:

           list3 = sorted(list2,reverse=True)

           for j in list3:

               file3.write(str(j))

       print("reversed : ")

       print(list3)

       file3.close()


    结果：

    please input a list,like( 1,2,3): 1,3,5,7,9,0,2,4,6,8

    oringin date:

    [1, 3, 5, 7, 9, 0, 2, 4, 6, 8]

    sorted:

    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

    read data:

    ['0\n', '1\n', '2\n', '3\n', '4\n', '5\n', '6\n', '7\n', '8\n', '9\n']

    reversed :

    ['9\n', '8\n', '7\n', '6\n', '5\n', '4\n', '3\n', '2\n', '1\n', '0\n']




    2.分别把 string， list， tuple， dict写入到文件中

    # 1）字符串

    import codecs

    str1= raw_input("please input a string: ")

    with codecs.open("example.txt","w") as file1:

       file1.write(str1)

       file1.close()


    运行：please input a string: huangzhenping

    结果：huangzhenping


    # 2）列表和元组

    import codecs

    list2 = list(raw_input("please input a list: "))

    with codecs.open("example.txt","w") as file2:

       for i in list2:

           file2.write(str(i))

       file2.close()


    运行：please input a list: a,b,c,1,2,3

    结果：a,b,c,1,2,3



    # 3）字典

    import codecs

    dict1 = dict(name="hzp",sex="male",age="27")

    with codecs.open("example.txt","w") as file3:

       for x,y in dict1.iteritems():

           file3.write(str(x) + ":" + str(y) + "\n")

       file3.close()



    结果：

    age:27

    name:hzp

    sex:male


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