File Handling

File handling is an essential aspect of programming, especially in data science and data analysis tasks. It involves reading data from files, writing data to files, and manipulating files.

In Python, you can perform file handling operations using the built-in open() function and various file methods.

To read data from a file, you can use the read(), readline(), or readlines() methods. The read() method reads the entire contents of the file as a string, while the readline() method reads one line at a time. The readlines() method reads all lines in the file and returns them as a list of strings.

Here's an example of reading data from a file:

1# Open the file in read mode
2file = open('data.txt', 'r')
3
4# Read the entire contents of the file
5content = file.read()
6
7# Close the file
8file.close()
9
10# Print the contents
11print(content)

To write data to a file, you can use the write() method. This method writes a string to the file. If the file does not exist, it will be created. If the file already exists, the existing contents will be overwritten.

Here's an example of writing data to a file:

1# Open the file in write mode
2file = open('output.txt', 'w')
3
4# Write the data to the file
5file.write('Hello, World!')
6
7# Close the file
8file.close()

File handling also includes other operations such as creating new files, deleting files, and renaming files. Python provides methods like os.path.exists(), os.remove(), and os.rename() for performing these operations.

Understanding file handling in Python is crucial for data scientists and analysts, as it allows them to work with different types of data stored in files and automate data processing tasks.