- Python Basics
- Python - Home
- Python - Overview
- Python - History
- Python - Features
- Python vs C++
- Python - Hello World Program
- Python - Application Areas
- Python - Interpreter
- Python - Environment Setup
- Python - Virtual Environment
- Python - Basic Syntax
- Python - Variables
- Python - Data Types
- Python - Type Casting
- Python - Unicode System
- Python - Literals
- Python - Operators
- Python - Arithmetic Operators
- Python - Comparison Operators
- Python - Assignment Operators
- Python - Logical Operators
- Python - Bitwise Operators
- Python - Membership Operators
- Python - Identity Operators
- Python - Operator Precedence
- Python - Comments
- Python - User Input
- Python - Numbers
- Python - Booleans
- Python Control Statements
- Python - Control Flow
- Python - Decision Making
- Python - If Statement
- Python - If else
- Python - Nested If
- Python - Match-Case Statement
- Python - Loops
- Python - for Loops
- Python - for-else Loops
- Python - While Loops
- Python - break Statement
- Python - continue Statement
- Python - pass Statement
- Python - Nested Loops
- Python Functions & Modules
- Python - Functions
- Python - Default Arguments
- Python - Keyword Arguments
- Python - Keyword-Only Arguments
- Python - Positional Arguments
- Python - Positional-Only Arguments
- Python - Arbitrary Arguments
- Python - Variables Scope
- Python - Function Annotations
- Python - Modules
- Python - Built in Functions
- Python Strings
- Python - Strings
- Python - Slicing Strings
- Python - Modify Strings
- Python - String Concatenation
- Python - String Formatting
- Python - Escape Characters
- Python - String Methods
- Python - String Exercises
- Python Lists
- Python - Lists
- Python - Access List Items
- Python - Change List Items
- Python - Add List Items
- Python - Remove List Items
- Python - Loop Lists
- Python - List Comprehension
- Python - Sort Lists
- Python - Copy Lists
- Python - Join Lists
- Python - List Methods
- Python - List Exercises
- Python Tuples
- Python - Tuples
- Python - Access Tuple Items
- Python - Update Tuples
- Python - Unpack Tuples
- Python - Loop Tuples
- Python - Join Tuples
- Python - Tuple Methods
- Python - Tuple Exercises
- Python Sets
- Python - Sets
- Python - Access Set Items
- Python - Add Set Items
- Python - Remove Set Items
- Python - Loop Sets
- Python - Join Sets
- Python - Copy Sets
- Python - Set Operators
- Python - Set Methods
- Python - Set Exercises
- Python Dictionaries
- Python - Dictionaries
- Python - Access Dictionary Items
- Python - Change Dictionary Items
- Python - Add Dictionary Items
- Python - Remove Dictionary Items
- Python - Dictionary View Objects
- Python - Loop Dictionaries
- Python - Copy Dictionaries
- Python - Nested Dictionaries
- Python - Dictionary Methods
- Python - Dictionary Exercises
- Python Arrays
- Python - Arrays
- Python - Access Array Items
- Python - Add Array Items
- Python - Remove Array Items
- Python - Loop Arrays
- Python - Copy Arrays
- Python - Reverse Arrays
- Python - Sort Arrays
- Python - Join Arrays
- Python - Array Methods
- Python - Array Exercises
- Python File Handling
- Python - File Handling
- Python - Write to File
- Python - Read Files
- Python - Renaming and Deleting Files
- Python - Directories
- Python - File Methods
- Python - OS File/Directory Methods
- Object Oriented Programming
- Python - OOPs Concepts
- Python - Object & Classes
- Python - Class Attributes
- Python - Class Methods
- Python - Static Methods
- Python - Constructors
- Python - Access Modifiers
- Python - Inheritance
- Python - Polymorphism
- Python - Method Overriding
- Python - Method Overloading
- Python - Dynamic Binding
- Python - Dynamic Typing
- Python - Abstraction
- Python - Encapsulation
- Python - Interfaces
- Python - Packages
- Python - Inner Classes
- Python - Anonymous Class and Objects
- Python - Singleton Class
- Python - Wrapper Classes
- Python - Enums
- Python - Reflection
- Python Errors & Exceptions
- Python - Syntax Errors
- Python - Exceptions
- Python - try-except Block
- Python - try-finally Block
- Python - Raising Exceptions
- Python - Exception Chaining
- Python - Nested try Block
- Python - User-defined Exception
- Python - Logging
- Python - Assertions
- Python - Built-in Exceptions
- Python Multithreading
- Python - Multithreading
- Python - Thread Life Cycle
- Python - Creating a Thread
- Python - Starting a Thread
- Python - Joining Threads
- Python - Naming Thread
- Python - Thread Scheduling
- Python - Thread Pools
- Python - Main Thread
- Python - Thread Priority
- Python - Daemon Threads
- Python - Synchronizing Threads
- Python Synchronization
- Python - Inter-thread Communication
- Python - Thread Deadlock
- Python - Interrupting a Thread
- Python Networking
- Python - Networking
- Python - Socket Programming
- Python - URL Processing
- Python - Generics
- Python Libraries
- NumPy Tutorial
- Pandas Tutorial
- SciPy Tutorial
- Matplotlib Tutorial
- Django Tutorial
- OpenCV Tutorial
- Python Miscellenous
- Python - Date & Time
- Python - Maths
- Python - Iterators
- Python - Generators
- Python - Closures
- Python - Decorators
- Python - Recursion
- Python - Reg Expressions
- Python - PIP
- Python - Database Access
- Python - Weak References
- Python - Serialization
- Python - Templating
- Python - Output Formatting
- Python - Performance Measurement
- Python - Data Compression
- Python - CGI Programming
- Python - XML Processing
- Python - GUI Programming
- Python - Command-Line Arguments
- Python - Docstrings
- Python - JSON
- Python - Sending Email
- Python - Further Extensions
- Python - Tools/Utilities
- Python - GUIs
- Python Useful Resources
- Python Compiler
- NumPy Compiler
- Matplotlib Compiler
- SciPy Compiler
- Python - Programming Examples
- Python - Quick Guide
- Python - Useful Resources
- Python - Discussion
Python os.ftruncate() Method
The Python os.ftruncate() method truncates the data from the end of a file corresponding to the given file descriptor. It will reduce the file data to a specified length.
If the specified length is greater than or equal to the size of the file, the file remains unchanged.
Syntax
Following is the syntax for ftruncate() method −
os.ftruncate(fd, length)
Parameters
The Python os.ftruncate() method accepts the following parameters −
fd − This is the file descriptor, which needs to be truncated.
length − This is the length of the file where file needs to be truncated.
Return Value
The Python os.ftruncate() method does not return any value.
Example
The following example shows the usage of ftruncate() method. Here, we open a file in read/write mode and then remove the file data except the first 10 bytes.
#!/usr/bin/python import os, sys # Open a file fd = os.open( "foo.txt", os.O_RDWR|os.O_CREAT ) # Write one string os.write(fd, b"This is test - This is test") # using ftruncate() method. os.ftruncate(fd, 10) # Now read this file from the beginning os.lseek(fd, 0, 0) str = os.read(fd, 100) print ("The available String : ", str) # Close opened file os.close( fd ) print ("Closed the file successfully!!")
When we run above program, it produces following result −
The available String : b'This is te' Closed the file successfully!!
Example
In the following example, we are using os.ftruncate() method with a File Objects. We use the "with" statement to open and close the file. We write a string to the file, truncate it to eight bytes, and then read from the beginning to print the remaining string.
import os # Open a file with open("foo.txt", "r+") as file: # Writing to the file file.write("Python with Tutorialspoint") # Flush the write buffer file.flush() # get the file descriptor fd = file.fileno() # Truncating the file os.ftruncate(fd, 8) # Read the file file.seek(0) print(file.read())
On executing the above program, it produces following result −
Python w
To Continue Learning Please Login
Login with Google