Python文件和流

#coding = utf-8

from pprint import pprint

import fileinput

#read(n)

f = open(r'E:\test_dir\somefile.txt', 'r')

a=f.read(7) #读7个字符

b=f.read(4)

print a

print b

f.close()

print

#read()

f = open(r'E:\test_dir\somefile.txt', 'r')

print f.read()

f.close()

print

#readline()

f = open(r'E:\test_dir\somefile.txt')

for i in range(3):

print str(i) + ':'+f.readline()

f.close()

print

##readlines()

pprint(open(r'E:\test_dir\somefile.txt').readlines())

print

#写文件

f = open(r'E:\test_dir\somefile1.txt', 'w')

f.write('this\nis no\nhaiku')

f.close()

f = open(r'E:\test_dir\somefile1.txt', 'r')

print f.readlines()

print

#修改文本文件

#writelines(list)

f = open(r'E:\test_dir\somefile1.txt' )

lines = f.readlines()

f.close()

lines[1]="isn't a\n"

f = open(r'E:\test_dir\somefile1.txt', 'w')

f.writelines(lines)

f.close()

print

def process(string):

print 'Processing:',string

#按字节处理

f = open(r'E:\test_dir\somefile1.txt' )

char =f.read(1)

while char:

process(char)

char =f.read(1)

f.close()

print

#按行操作

f = open(r'E:\test_dir\somefile1.txt' )

while True:

line=f.readline()

if not line:break

process

f.close()

print

#用read迭代每个字符

f = open(r'E:\test_dir\somefile1.txt' )

for char in f.read():

process(char)

f.close()

print

#用readlines迭代行

f = open(r'E:\test_dir\somefile1.txt' )

for line in f.readlines():

process(line)

f.close()

#使用fileinput

for line in fileinput.input(r'E:\test_dir\somefile1.txt'):

process(line)

f.close()

print

#文件迭代器

f = open(r'E:\test_dir\somefile2.txt','w')

f.write('First line\n')

f.write('Second line\n')

f.write('Third line\n')

f.close()

lines = list(open(r'E:\test_dir\somefile2.txt'))

print lines

a,b,c=open(r'E:\test_dir\somefile2.txt')

print a

print b

print c