python 基础 3.2 文件 for 练习

#/usr/bin/python

#coding=utf-8

#@Time   :2017/11/1 22:19

#@Auther :liuzhenchuan

#@File   :1030-1031练习题.py

 

###1 把一个数字的list从小到大排序，然后写到文件中，然后从文件中读取文件内容然后反序，在追加到文件的

   #下一行中

###2 分别把string list tuple dict 写到文件中

import codecs

 

l1 = [51,34,67,8,10,11,9]

l1.sort()

l2 = str(l1)

print l2

 

with open('a.txt','w+') as fd:

    for i in l2:

        fd.write(str(i))

    fd.write('\n')

    fd.close()

  #打印出文件内容

with open('a.txt') as fd:

    print fd.read(),

 

#反序追加到文件的下一行中

l1.reverse()

l3 = str(l1)

with open('a.txt','a') as fd:

    for j in l3:

        fd.write(str(j))

        # fd.write('\n')

    fd.close()

#打印出文件内容

with open('a.txt') as fd:

    print fd.read()

>>> [8, 9, 10, 11, 34, 51, 67]
　　[67, 51, 34, 11, 10, 9, 8]

 

####2 分别把string list tuple dict 写到文件中去

#把字符串写到文件中去

str1 = 'abcde'

with open('b.txt','w+') as f:

    f.write(' '.join(str1))

with open('b.txt') as f:

    print f.read()

>>> a b c d e

 

#把列表写到字符串中去,并用空格隔开每个字符

list1 = [1,2,3,4,5,6]

with open('c.txt','w+') as f1:

    # for i in list1:

    #     f1.write(str(i))

    # f1.close()

    f1.write(''.join([str(i)+' ' for i in list1 ]))

with open('c.txt') as f1:

    print f1.read()

>>> 1 2 3 4 5 6

 

#把元组写到文件中去

tuple1 = ('1','2','a','b')

with codecs.open('d.txt','w+') as f2:

f2.write(str(tuple1) + '\n')

f2.close()

with codecs.open('d.txt') as f2:

    print f2.read()

>>> ('1', '2', 'a', 'b')

 

#把字典写到文件中去

dict1 = {'a':'1','b':2,'c':3}

with open('e.txt','w+') as f3:

    f3.write(str(dict1))

with open('e.txt') as f3:

    print f3.read()

>>> {'a': '1', 'c': 3, 'b': 2}