File I/O | nji

Python Programming For Beginners

Reading from and Writing to Files

Definition: File I/O (Input/Output) operations allow you to read from and write to files.

Opening a File: Use the open() function to open a file. The mode specifies whether you want to read ('r'), write ('w'), or append ('a') to the file. python

file = open("example.txt", "r") # Open for reading file = open("example.txt", "w") # Open for writing file = open("example.txt", "a") # Open for appending

Reading from a File: Use methods like read(), readline(), or readlines() to read the content. python
```
file = open("example.txt", "r") content = file.read() print(content) file.close()
```
Writing to a File: Use the write() method to write content to a file. python
```
file = open("example.txt", "w") file.write("Hello, World!") file.close()
```
Using with Statement: The with statement ensures that the file is properly closed after its suite finishes. python
```
with open("example.txt", "r") as file: content = file.read() print(content)
```

Working with File Paths

Definition: File paths specify the location of a file in the file system.
Absolute vs. Relative Paths:
- Absolute Path: Specifies the complete path from the root directory. python
```
file = open("/home/user/example.txt", "r")
```
- Relative Path: Specifies the path relative to the current working directory. python
```
file = open("example.txt", "r")
```

Using os and pathlib Modules: These modules provide functions to work with file paths. python

import os print(os.path.abspath("example.txt")) # Output: /home/user/example.txt from pathlib import Path print(Path("example.txt").resolve()) # Output: /home/user/example.txt