复习作业

复习作业

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

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

 

1，利用ast.literal_eval，将字符串型的list,tuple,dict转变成原有的类型

 

import codecs
import ast

L = [2,4,6,8,9,1,3,5,7,23,567,356]

with codecs.open('1.txt', 'wb') as f:
    f.write(str(sorted(L)))

with codecs.open('1.txt', 'rb') as f1:
    a = f1.read()
    L2 = ast.literal_eval(a)
    L2.reverse()

with codecs.open('1.txt', 'ab') as f2:
    f2.write('\n')
    f2.write(str(L2))

with codecs.open('1.txt', 'rb') as f2:
    L3 = f2.read()
    print L3

 

结果

[1, 2, 3, 4, 5, 6, 7, 8, 9, 23, 356, 567]
[567, 356, 23, 9, 8, 7, 6, 5, 4, 3, 2, 1]

 2 

#!/usr/bin/env python
# coding=utf-8
import codecs
import ast

#string写入文件
with codecs.open('2.txt','wb') as f:
    f.write('python')
    f.write('\n')

##list写入
L = [1,'a','b',4,'python']
with codecs.open('2.txt','ab') as f:
    f.write(str(L))
    f.write('\n')

##tuple写入
T = (2,'c','py',5)
with codecs.open('2.txt','ab') as f:
    f.write(str(T))
    f.write('\n')

##dict写入
D = {'name':'liang','age':100}
with codecs.open('2.txt','ab') as f:
    f.write(str(D))
    f.write('\n')

##内容打印
with codecs.open('2.txt','rb') as f:
    f.seek(0)
    S1 = f.readline()
    L1 = ast.literal_eval(f.readline())
    T1 = ast.literal_eval(f.readline())
    D1 = ast.literal_eval(f.readline())
    for i in (S1,L1,T1,D1):
        print i
        print type(i)

结果

python
<type 'str'>
[1, 'a', 'b', 4, 'python']
<type 'list'>
(2, 'c', 'py', 5)
<type 'tuple'>
{'age': 100, 'name': 'liang'}
<type 'dict'>

 

 

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