File Handling in Python: Opening and Reading Files

Understanding how to handle files is essential for any Python developer. This post explores the built-in open() function, which allows you to interact with files on your server.

Opening a File

To start, assume you have a text file named samplefile.txt located in the same folder as your Python script:

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

If your file is located in a different directory, specify the full file path:

file = open("C:\\myfiles\\welcome.txt", "r")
print(file.read())

Reading Specific Parts of the File

The read() method returns the entire text by default, but you can specify how many characters to read:

file = open("samplefile.txt", "r")
print(file.read(5))

Reading Lines

To read the file line by line, use the readline() method:

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

You can call readline() multiple times to read additional lines:

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

To read the entire file line by line, you can loop through the file object:

file = open("samplefile.txt", "r")
for line in file:
print(line)

Closing Files

It is best practice to close the file when you're done:

file = open("samplefile.txt", "r")
print(file.readline())
file.close()

Remember, failing to close a file can lead to issues with data not being saved properly.

Conclusion

File handling is a vital skill in Python programming. The open() function and its associated methods allow you to read and manage files effectively. Always ensure to close your files after use to avoid any potential issues.