Python File Operations

File operations are common in Python. Python provides powerful file handling capabilities that facilitate reading and writing data within programs.

File Opening

There are many ways to open a file in Python. The most common method is to use the open function:

file = open("filename","mode")

Where “filename” is the file path, and “mode” specifies the file opening requirements. Common modes are as follows:

• “r”: Read mode (default). This mode opens the file for read-only operation.
• “w”: Write mode, used to clear the original file contents and write data.
• “x” : Exclusive write mode, used when creating a new file; an error will be reported if the file already exists.
• “a” : Append mode, used to add content to the end of a file.
• “b” : Binary mode, used to open binary files (such as images or audio).
• “t” : Text mode (default), used to open text files.

The sample code is as follows:

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

The sample code uses the file “test.txt” as an example.

File Reading

Python provides multiple methods for reading file contents. The most common way to read is to use the read() or readline() functions.

The
• read() function reads the entire file contents one by one.

file = open("test.txt","r")
content = file.read()
print(content)

The
• readline() function reads the file contents line by line.

file = open("test.txt","r")
content = file.readline()
print(content)

The
• readlines() function receives the file contents as a list.

file = open("test.txt","r")
content = file.readlines()
print(content)

File Writing

Python provides the following functions for writing file contents:

The
• write() function is used to write a string to a file.

file = open("test.txt","w")
file.write("hello world")
file.close()

The last line of code closes the file; operations can only be performed after the file is closed.

File Closing

After opening a file using the open function, you need to close it to release resources. You can use the close() method to do this.

The following example is as follows:

file = open("test.txt","r")
print(file.read())
file.close()

Context Managers

Use the more concise methods above to open and close files. Context managers ensure proper resource cleanup and can be used within the with statement.

with open("test.txt","r") as file:
print(file.read())

In this case, the file is opened and automatically closed after execution.

Conclusion

Reading, writing, and manipulating files is easy in Python, using the open function, the read() method, and the write() method. Finally, whether you are reading or writing files, always remember to close them!