Python file input/output example

Python file input/output example

Here is an example of reading and writing to a text file using Python:

# Read from a text file
def read_from_file(file_name):
try:
with open(file_name, 'r') as f:
content = f.read()
return content
except FileNotFoundError:
print(f"The file {file_name} does not exist.")
return None
Write to a text file
def write_to_file(file_name, content):
try:
with open(file_name, 'w') as f:
f.write(content)
except IOError:
print(f"An error occurred while writing to the file {file_name}.")
return False
Example usage
if name == "main":
Read from a text file
content = read_from_file('input.txt')
if content is not None:
print("Content of input.txt:n", content)
Write to a text file
new_content = "Hello, World!nThis is a test."
write_to_file('output.txt', new_content)

In this example, we have two functions: read_from_file and write_to_file. The read_from_file function takes the name of a file as input and tries to open it in read mode. If the file exists, it reads the content of the file and returns it. If the file does not exist, it prints an error message and returns None.

The write_to_file function also takes two inputs: the name of a file and some content. It tries to open the file in write mode and writes the content to the file. If an error occurs while writing to the file (for example, if the file is already being used by another program), it prints an error message.

In the __main__ block, we demonstrate how to use these functions by reading from a text file named 'input.txt', and then writing some new content to a text file named 'output.txt'.

Here are the steps to run this example:

Remember that Python programs are case-sensitive and require correct syntax.

File input output in Python w3schools

I cannot provide a file for input/output operations in Python using W3Schools as it is a website that provides tutorials and exercises on web development, including Python programming. However, I can provide you with an example of how to achieve this using the built-in input() function in Python to get user's input and then printing it out.

Here is a simple Python program that demonstrates how to take user's input through the console and print it back:

# Take input from user
user_input = input("Enter your name: ")
Print the input back
print(f"Hello, {user_input}!")

To run this code, you can copy it into a Python file (e.g., hello.py), then save it and execute it using a Python interpreter like Python 3.8:

You'll see the output prompt: "Enter your name: ", and type in your name, after pressing Enter, it will print out a greeting message with your name.

For more advanced file input/output operations, such as reading from or writing to files, you can use Python's built-in file I/O functions:

# Read from a file named "user.txt"
try:
user_file = open("user.txt", 'r')
user_input = user_file.read().strip()
user_file.close()
except FileNotFoundError:
print("File not found.")

Or:

# Write to a file named "user.txt"
with open('user.txt', 'w') as f:
f.write(input("Enter your name: "))

Remember that these examples are for illustration purposes only. Always be careful when handling user input and files, as it can impact the security of your system if not done properly.

This is a basic example of how to achieve file input/output in Python using W3Schools.