3.python文件操作

床前明月光，疑是地上霜
举头望明月，低头思故乡

f = open('libai',encoding = 'utf-8')
print(f.read())

床前明月光，疑是地上霜
举头望明月，低头思故乡

f = open('libai',encoding = 'utf-8')

print(f.readline())

床前明月光，疑是地上霜

f = open('libai',encoding = 'utf-8')

print(f.readlines())

['床前明月光，疑是地上霜\n', '举头望明月，低头思故乡']

f = open('libai',encoding='utf-8')
data = f.read()     #默认光标在起始的位置，read()读取完后，光标停留到文件末尾
data2 = f.read()    #data2读取的内容为空
print(data)
print(data2)
f.close()          #关闭文件

abcdefg
hyjklmn
opqrstu
vwxyz

f = open('libai',encoding='utf-8')
#tell获取当前的光标
print(f.tell())    #0

print(f.readline().strip())
print(f.readline().strip())
print(f.tell())
f.seek(0)     #移动光标到文件起始的地方
print(f.readline().strip())


结果：
0
abcdefg
hyjklmn
18
abcdefg

import sys,time

for i in range(40):
    sys.stdout.write('#')
    sys.stdout.flush()     #flush强制舒心缓存到内存的数据写入硬盘
    time.sleep(0.1)

with open('libai') as f:
    print(f.read())

#rb  二进制模式读取
f = open('libai','rb')  #主要用于网络传输
print(f.readline())

f = open('libai','wb')
f.write('中文'.encode())