Python3 os.ftruncate() Method
Python3 OS File/Directory Methods
Overview
os.ftruncate() truncates the file corresponding to the file descriptor fd; it cannot exceed the file size.
Available on Unix.
Syntax
ftruncate()The method syntax is as follows:
os.ftruncate(fd, length)¶
Parameters
fd-- file descriptor.
length-- the file size to truncate.
Return Value
This method has no return value.
Example
The following example demonstrates the use of the ftruncate() method:
#!/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 output of executing the above program is:
读取的字符串是 : This is te 关闭文件成功!!Other Extensions