File handling(Python)

Japanese version.

File handling refers to the process of reading, creating, and updating files on a computer. Python provides a number of functions for working with files, making it very easy to manipulate files in your programs.

The basic steps involved in file handling with Python are as follows:

  • Open the file.
  • Read or write the file.
  • Close the file.

Python's file handling capabilities are very powerful and provide a lot of options. Always be sure to close files that you have opened.

Basic syntax

To manipulate text files in Python, the language provides standard file objects. To write to or read from a text file, follow these steps:

  • Use the open() function to open the file. When opening the file, specify the filename and the mode. Modes can include read mode (r), write mode (w), append mode (a), and more.
  • If writing to the file, use the write() method. If reading from the file, use the read() method.
  • Use the close() method to close the file. Closing the file releases access to the file.

Here is an example of writing a string to a text file:

# Open the file
file = open("C:\python\example.txt", "w")

# Write a string to the file
file.write("Hello, world!")

# Close the file
file.close()

In this example, we use the open() function to open the file and the write() method to write a string to the file. Finally, we use the close() method to close the file.

Here is an example of reading data from a text file:

# Open the file
file = open("C:\python\example.txt", "r")

# Read data from the file
data = file.read()

# Close the file
file.close()

# Print the read data
print(data)

In this example, we use the open() function to open the file, the read() method to read data from the file, and the close() method to close the file. Finally, we print the read data.

Context manager

In Python, a context manager is a mechanism for automatically allocating and releasing resources. Context managers are typically used with the with statement.

For example, when working with files, it is important to always remember to close the file after opening it. By using a context manager, the necessary operations for opening the file can be performed automatically, and you don't have to worry about forgetting to close the file.

Here is an example of using a context manager to open a file and write data to it:

with open("C:\python\example.txt", "w") as file:
    file.write("Hello, world!")

In this example, we use the open() function with a with statement to open the file and the write() method to write data to it. When the with block is exited, the file is automatically closed.

with open("C:\python\example.txt", "r") as file:
    data = file.read()

print(data)

Similarly, you can use a context manager to read data from a file:

In this example, we use the open() function with a with statement to open the file and the read() method to read data from it. When the with block is exited, the file is automatically closed.

By using context managers, you can automate the allocation and release of resources, making your code simpler and easier to read.

For those who want to learn Python efficiently.

The information on this site is now available in an easy-to-read e-book format for $3.00.

Or Kindle Unlimited (unlimited reading).

This textbook is used for new employees with no programming experience.

This book focuses on basic programming topics.

We do not cover topics such as object-oriented programming, statistical analysis using Python-specific libraries, machine learning, as these topics are difficult to understand from the standpoint of initial programming learning.

This book is especially recommended for those who have no experience with programming.

Click here to buy!!

Links

Python Articles

Python

Python