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File IO in Python

 


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File IO in Python

File Input/Output (IO) operations allow you to read from and write to files. Python provides built-in functions and methods for file handling.

1. Opening a File

Use the open() function to open a file. It returns a file object and takes two parameters: the file name and the mode (e.g., read, write, append).


# Open a file in read mode
file = open('example.txt', 'r')

2. Reading from a File

After opening a file, you can read its contents using methods like read(), readline(), or readlines().


# Read entire content of the file
content = file.read()
print(content)

# Don't forget to close the file
file.close()

3. Writing to a File

Open a file in write ('w') or append ('a') mode to write data to it.


# Open a file in write mode
file = open('example.txt', 'w')

# Write a string to the file
file.write('Hello, World!')

# Close the file
file.close()

4. Using the with Statement

The with statement is used to wrap the execution of a block of code within methods defined by the context manager. It ensures that the file is properly closed after its suite finishes, even if an exception is raised.


# Using 'with' to open a file
with open('example.txt', 'r') as file:
    # Read the file's content
    content = file.read()
    print(content)

5. File Modes

Different modes can be used with the open() function:

  • 'r': Read (default mode)
  • 'w': Write (truncates the file)
  • 'a': Append
  • 'b': Binary mode
  • 't': Text mode (default mode)
  • '+': Read and write

# Example of opening a file in binary read mode
file = open('example.txt', 'rb')
# Example of opening a file in binary write mode
file = open('example.txt', 'wb')
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