Python3 os.ftruncate () method
Python3 OS file / directory methods
Outline
os.ftruncate () file descriptor fd corresponding crop, it can not exceed the maximum file size.
Available on Unix.
grammar
ftruncate () method syntax is as follows:
os.ftruncate(fd, length)¶
parameter
fd - the file descriptor.
length - the size of the file you want to crop.
return value
This method has no return value.
Examples
The following example demonstrates ftruncate () method of use:
#!/usr/bin/python3 import os, sys # 打开文件 fd = os.open( "foo.txt", os.O_RDWR|os.O_CREAT ) # 写入字符串 os.write(fd, "This is test - This is test") # 使用 ftruncate() 方法 os.ftruncate(fd, 10) # 读取内容 os.lseek(fd, 0, 0) str = os.read(fd, 100) print ("读取的字符串是 : ", str) # 关闭文件 os.close( fd) print ("关闭文件成功!!")
The above program output is:
读取的字符串是 : This is te 关闭文件成功!!