File Handling and I/O Operations

File Handling and I/O Operations

File Handling Basics:

1. Opening a File:

• Using the open() function to open a file for reading or writing.
• Specifying the file path and mode ("r" for reading, "w" for writing, "a" for appending, etc.).

2. Reading from a File:

• Using the .read() method to read the entire file content.
• Using .readline() to read one line at a time.
• Using .readlines() to read all lines into a list.

3. Closing a File:

• Using the .close() method to properly close the file.
• Ensuring that resources are released when the file is no longer needed.

4. Writing to a File:

• Using the .write() method to write text to a file.
• Using .writelines() to write a list of strings to a file.

Context Managers and with Statement:

1. Using with Statement:

• Using the with statement to automatically handle file closing.
• Ensuring proper resource management and error handling.

2. File Objects as Context Managers:

• File objects obtained from open() can be used as context managers.
• Simplifying file handling code with the with statement.

Reading and Writing Text Files:

1. Reading Text Files:

• Using open() with mode "r" to read text files.
• Iterating through lines using a loop.

2. Writing Text Files:

• Using open() with mode "w" to write to a text file.
• Writing multiple lines using .write() or .writelines().

3. Appending to Text Files:

• Using mode "a" to append content to an existing file.
• Adding new content without overwriting the existing data.

Working with Binary Files:

1. Reading Binary Files:

• Using mode "rb" to read binary files.
• Reading bytes and byte arrays.

2. Writing Binary Files:

• Using mode "wb" to write to binary files.
• Writing bytes or byte arrays to a file.

File Paths and Directories:

1. File Paths:

• Using relative and absolute paths to specify file locations.
• Handling slashes/backslashes based on the operating system.

2. Working with Directories:

• Using os module for working with directories.
• Listing files, creating directories, etc.

3. Working with Pathlib:

• Using the pathlib module for modern file path manipulation.
• Creating paths, joining paths, checking existence, etc.

Exception Handling and Error Management:

1. Handling File-Related Errors:

• Using try and except to handle file-related exceptions.
• Ensuring graceful handling of issues like file not found.

2. Using os.path for Validation:

• Using functions from os.path module to validate file paths.
• Checking if a file exists, checking its type, etc.

3. Handling Resource Leaks:

• Ensuring that files are properly closed even in the presence of exceptions.
• Using finally block or with statement for cleanup.

CSV and Text File Parsing:

1. Reading CSV Files:

• Using the csv module to read and parse CSV files.
• Reading rows and fields as lists or dictionaries.

2. Writing CSV Files:

• Using the csv module to write data to CSV files.
• Writing rows based on lists or dictionaries.