Python 第三周作业

Posted 2020-10-12

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： 

In [13]: l = [2, 32, 43, 453, 54, 6, 576, 5, 7, 6, 8, 78, 7, 89]

In [14]: l.sort()

In [17]: with open(‘1.txt‘, ‘w‘) as fd:
   ....:     fd.write(str(l))
   ....:     

In [18]: with open(‘1.txt‘) as fd:
   ....:     print fd.read()
   ....:     
[2, 5, 6, 6, 7, 7, 8, 32, 43, 54, 78, 89, 453, 576]

2、然后反序，再追加到文件的下一行中：

In [19]: l.reverse()

In [20]: with open(‘1.txt‘, ‘a‘) as fd:
   ....:     fd.write(str(l))
   ....:     

In [21]: with open(‘1.txt‘) as fd:
   ....:     print fd.read()
   ....:     
[2, 5, 6, 6, 7, 7, 8, 32, 43, 54, 78, 89, 453, 576]
[576, 453, 89, 78, 54, 43, 32, 8, 7, 7, 6, 6, 5, 2]

3、分别把 string， list， tuple， dict 写入到文件中：

In [21]: string = ‘abc‘
In [22]: list = [‘a‘, ‘b‘, ‘c‘]
In [23]: tuple = (‘a‘, ‘b‘, ‘c‘)
In [24]: dict = {1:‘a‘, 2:‘b‘, 3:‘c‘}

In [25]: with open(‘1.txt‘, ‘w‘) as fd:
   ....:     fd.write(string+‘\n‘)
   ....:     fd.write(str(list)+‘\n‘)
   ....:     fd.write(str(tuple)+‘\n‘)
   ....:     fd.write(str(dict))
   ....:     

In [26]: with open(‘1.txt‘) as fd:
   ....:     print fd.read()
   ....:     
abc
[‘a‘, ‘b‘, ‘c‘]
(‘a‘, ‘b‘, ‘c‘)
{1: ‘a‘, 2: ‘b‘, 3: ‘c‘}