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Introduction
- File handling in Python allows us to read, write, and manipulate files (text or binary) stored on our system.
- Python provides several built-in functions to work with files such as open(), remove(), write(), etc.
Definition
- A file in Python is a storage unit on a computer where data can be stored permanently.
File Modes in Python
Mode : Description
“r” : Read (default) – Opens file for reading; error if file doesn’t exist.
“w” : Write – Creates a file if it doesn‘t exist; overwrites if it exists.
“a” : Append – Opens file for writing; does not overwrite existing content.
“x” : Exclusive creation – Creates a new file; fails if file exists.
“t” : Text mode (default) – Handles text files.
“b” : Binary mode – Handles binary files (images, videos, etc.).
Types of Files in Python
Two types –
Text Files (.txt, .csv, .log)
-
- These files store readable characters (letters, numbers, symbols).
- Example: “Hello, World!” in a .txt file.
Binary Files (.jpg, .pdf, .exe)
-
- These files store non-readable data (machine code).
- Example: Images, videos, executables.
File Operations
🔹 Opening a File
Syntax:
file = open(“filename.txt”, “mode”)
where, “filename.txt” → The name of the file.
“mode” → Specifies how the file is opened (read, write, append, etc.).
🔹 Writing to a File
Syntax:
file = open(“example.txt”, “w”) # Open file in write mode
file.write(“Hello, this is a file handling example in Python.”)
file.close() # Always close the file
NB: If the file already exists, its content is overwritten.
🔹 Reading a File
file = open(“example.txt”, “r”) # Open file in read mode
content = file.read() # Read entire file
print(content)
file.close()
Other Read Methods
file.read(10) # Read first 10 characters
file.readline() # Read one line at a time
file.readlines() # Read all lines as a list
🔹 Appending to a File
file = open(“example.txt”, “a”) # Open file in append mode
file.write(“\nThis is a new line added!”) # Append data
file.close()
NB : It does not overwrite existing content; it just appends at the end.
🔹 ‘with’ Statement in File
- Using the ‘with’ statement, the file is automatically closed.
with open(“example.txt”, “r”) as file:
content = file.read()
print(content) # File closes automatically after the block
🔹 Working with Binary Files
- This is applied for images, PDFs, etc.
with open(“image1.jpg”, “rb”) as file: # Read binary mode
data = file.read()
with open(“image2.jpg”, “wb”) as file: # Write binary mode
file.write(data)
🔹 Deleting a File
- The ‘os’ module is used to delete a file.
import os
if os.path.exists(“example.txt”):
os.remove(“example.txt”) # Deletes the file
else:
print(“File does not exist”)
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