Python学习系列（五）(文件操作及其字典)

1 #coding:utf-8
2 fn=‘test1.py‘
3 fp=open(fn,‘r‘) #以读的方式打开文件，文件必须首先存在和，.文件在同一目录下py
4 print ‘reading pos:‘,fp.tell()
5 r=fp.read(20) #读取文件内容返回字符串
6 print ‘have read:\"‘+r+‘\‘‘
7 print ‘reading pos:‘,fp.tell()
8 print fp.read()
9 fp.close()

1 fw=‘test.txt‘ 
2 fp=open(fw,‘w‘) 
3 fp.write(‘www.google.com‘) 
4 fp.close() 

1  fn=‘rplus.txt‘
2  fp=open(fn,‘w+‘) 
3  r=fp.read(12) 
4  print r 
5  fp.close()

 1 fn=‘rplus.txt‘
 2 fp=open(fn,‘w+‘)
 3 fp.write(‘aaaaa\n‘)
 4 fp.close()
 5  
 6 fa=open(‘rplus.txt‘,‘a‘)
 7 fa.write(‘bbbbb\n‘)
 8 fa.close()
 9  
10 fa=open(fn,‘r‘)
11 r=fa.read()
12 print r
13 fa.close()

1 fn=‘wformat.txt‘
2 fw=open(fn,‘w‘)
3 fw.write(‘%10s\t %3s\t %6s\n‘%(‘name‘,‘age‘,‘sex‘))
4 fw.write(‘%10s\t %3s\t %6s\n‘%(‘张三‘,78,‘male‘))
5 fw.write(‘%10s\t %3s\t %6s\n‘%(‘李四‘,50,‘male‘))
6 fw.write(‘%10s\t %3s\t %6s\n‘%(‘王五‘,80,‘male‘))
7 fw.write(‘%10s\t %3s\t %6s\n‘%(‘张强‘,90,‘female‘))
8 fw.close()

1 fr=open(‘templist.txt‘,‘r‘)
2 print fr.readlines()
3 fr.close()

1 >>>
2 [‘ aaaaaaaa\n‘, ‘ bbbbbbbb\n‘, ‘ cccccccc‘]

1 fr=open(‘templist.txt‘,‘r‘)
2 print fr.readline().strip().strip(‘\n‘)
3 print fr.readline().strip().strip(‘\n‘)
4 print fr.readline().strip().strip(‘\n‘)
5 fr.close() 

1 >>>
2 aaaaaaaa
3 bbbbbbbb
4 cccccccc

1 fr=open(‘wformat.txt‘,‘r‘)
2 line1=fr.readline()
3 print line1
4 line2=fr.readline()
5 print line2
6 print line2.split(‘\t‘)
7 fr.close()

1 >>>
2       name     age     sex
3  
4       张三     78     male
5  
6 [‘ \xd5\xc5\xc8\xfd‘, ‘ 78‘, ‘ male\n‘]

 1 fr=open(‘wformat.txt‘,‘r‘)
 2 while (1==1):
 3     line=fr.readline()
 4     if(line==‘‘):
 5         break
 6     else:
 7         print line
 8 fr.close()
 9  
10 >>> ================================ RESTART ================================
11 >>>
12       name     age     sex
13  
14       张三     78     male
15  
16       李四     50     male
17  
18       王五     80     male
19  
20       张强     90     female
21  
22 >>> 

1 fn=‘c:\\test.txt‘ 
2 fp=open(fn,‘w+‘) 
3 fp.write(‘www.python.com‘) 
4 fp.close() 

1 >>> dict1={‘a‘:‘b‘,‘name‘:‘jeap‘,12:34}
2 >>> len(dict1)
3 3

1 >>> dict1={‘a‘:‘b‘,‘name‘:‘jeap‘,12:34}
2 >>> print dict1[‘a‘],dict1[12]
3 b 34

1  >>> dict1[‘a‘]=‘hello‘
2 >>> print dict1
3 {‘a‘: ‘hello‘, 12: 34, ‘name‘: ‘jeap‘}

1 >>> del dict1[12]
2 >>> print dict1
3 {‘a‘: ‘hello‘, ‘name‘: ‘jeap‘}

1 >>> dict1[‘QQ‘]=‘649414754‘
2 >>> print dict1
3 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘}
4 >>> dict1[‘sex‘]=‘F‘
5 >>> print dict1
6 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘, ‘sex‘: ‘F‘}

1 >>> ‘name‘ in dict1
2 True
3 >>> ‘F‘ in dict1
4 False

1 >>> print dict1
2 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘, ‘sex‘: ‘F‘}
3 >>> dict1.clear()
4 >>> print dict1
5 {}

1 >>> dict1={‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘, ‘sex‘: ‘F‘}
2 >>> dict2=dict1.copy()
3 >>> print dict2
4 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘, ‘sex‘: ‘F‘}

1 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘jeap‘, ‘sex‘: ‘F‘}
2 >>> dict1.get(‘QQ‘)
3 ‘649414754‘

1 >>> dict1.keys()
2 [‘a‘, ‘QQ‘, ‘name‘, ‘sex‘]

1 >>> dict1.values()
2 [‘hello‘, ‘649414754‘, ‘jeap‘, ‘F‘]

1 >>> dict1.items()
2 [(‘a‘, ‘hello‘), (‘QQ‘, ‘649414754‘), (‘name‘, ‘jeap‘), (‘sex‘, ‘F‘)]

1 >>> new={‘age‘:32}  #原字典没有，新增
2 >>> add={‘name‘:‘张三‘} #原字典存在，更新‘jeap‘为‘张三‘
3 >>> dict1.update(new)
4 >>> dict1.update(add)
5 >>> print dict1
6 {‘a‘: ‘hello‘, ‘QQ‘: ‘649414754‘, ‘name‘: ‘\xd5\xc5\xc8\xfd‘, ‘age‘: 32, ‘sex‘: ‘F‘}

 1 >>> d0=dict() #创建空字典
 2 >>> print d0
 3 {}
 4 >>> d1=dict(name=‘zhangsan‘,QQ=‘123456789‘,age=23)#通过赋值创建字典
 5 >>> print d1
 6 {‘QQ‘: ‘123456789‘, ‘age‘: 23, ‘name‘: ‘zhangsan‘}
 7 >>> val=[‘lisi‘,‘649414754‘,25]
 8 >>> print val
 9 [‘lisi‘, ‘649414754‘, 25]
10 >>> key=range(1,4)
11 >>> d2=dict(zip(key,val))#使用一对列表创建字典
12 >>> print d2
13 {1: ‘lisi‘, 2: ‘649414754‘, 3: 25}

 1 >>> val=[‘Tom‘,‘Jack‘,‘Rose‘,‘John‘,‘Mark‘]
 2 >>> key=range(1,6)
 3 >>> dic=dict(zip(key,val))
 4 >>> print dic
 5 {1: ‘Tom‘, 2: ‘Jack‘, 3: ‘Rose‘, 4: ‘John‘, 5: ‘Mark‘}
 6 >>> dic.pop(2)
 7 ‘Jack‘
 8 >>> dic.popitem()
 9 (1, ‘Tom‘)
10 >>> print dic
11 {3: ‘Rose‘, 4: ‘John‘, 5: ‘Mark‘}

 1 >>> key=range(1,6)
 2 >>> val=[‘Tom‘,‘Jack‘,‘Rose‘,‘John‘,‘Mark‘]
 3 >>> dic=dict(zip(key,val))
 4 >>> for x in dic:
 5  print dic[x]
 6  
 7  
 8 Tom
 9 Jack
10 Rose
11 John
12 Mark

 1 >>> print dic.items()
 2 [(1, ‘Tom‘), (2, ‘Jack‘), (3, ‘Rose‘), (4, ‘John‘), (5, ‘Mark‘)]
 3 >>> for (k,v) in dic.items():
 4  print ‘dic[‘,k,‘]=‘,v
 5  
 6  
 7 dic[ 1 ]= Tom
 8 dic[ 2 ]= Jack
 9 dic[ 3 ]= Rose
10 dic[ 4 ]= John
11 dic[ 5 ]= Mark
12 >>>