Text Files

Understanding Text Files

Text files are the most common type of files used to store human-readable data. In Python, you can interact with text files using built-in functions and methods.

Opening a Text File

To work with a text file, you first need to open it using the open() function:

Python

file = open("filename.txt", "r")

·         filename: The name of the file you want to open.

·         mode: The mode in which you want to open the file. Common modes are:

o    'r': Read mode (default)

o    'w': Write mode (creates a new file or overwrites an existing one)

o    'a': Append mode (adds to the end of an existing file or creates a new one)

o    'x': Create mode (creates a new file, fails if the file already exists)

o    'r+': Read and write mode

Reading from a Text File

Once you have opened a file in read mode, you can read its contents using various methods:

·         read(): Reads the entire contents of the file as a single string.

·         readline(): Reads a single line from the file.

·         readlines(): Reads all lines of the file and returns them as a list of strings.

Python

file = open("my_file.txt", "r")

content = file.read()

print(content)

file.close()

Writing to a Text File

To write to a text file, open it in write or append mode:

Python

file = open("my_file.txt", "w")

file.write("This is some text.\n")

file.close()

Closing a File

It's essential to close a file after you're done using it to release system resources:

Python

file.close()

Using the with Statement

A more elegant and safer way to handle files is using the with statement:

Python

with open("my_file.txt", "r") as file:

  content = file.read()

  print(content)

The with statement automatically closes the file when the block ends, even if an exception occurs.

Additional Considerations

·         Encoding: Specify the encoding when opening the file if you know the character encoding (e.g., open("file.txt", "r", encoding="utf-8")).

·         Error handling: Use try-except blocks to handle potential errors like file not found or permission denied.

·         File modes: Explore other file modes like 'rb' for reading binary files.

By understanding these concepts, you can effectively work with text files in your Python programs.