File I/O in Python is the process of reading from and writing to files. Python provides several built-in functions for working with files, including the open() function for opening a file and the close() function for closing a file.
Here is an example of how to read from a text file in Python:
In this example, the open() function is used to open the file “example.txt” in read mode. The read() function is then used to read the contents of the file, and the close() function is used to close the file when we are done with it.
Here is an example of how to write to a text file in Python:
In this example, the open() function is used to open the file “example.txt” in write mode. The write() function is then used to write the text “Hello, World!” to the file, and the close() function is used to close the file when we are done with it.
Working with CSV and JSON files in Python is similar to working with text files, but you will need to use different libraries to read and write the data. For example, the csv library can be used to read and write CSV files, and the json library can be used to read and write JSON files.
Here is an example of how to read a CSV file in Python:
In this example, the open() function is used to open the file “example.csv” in read mode. The csv.reader() function is then used to create a reader object that can be used to read the contents of the CSV file. The for loop is used to iterate through the rows in the CSV file, and the print() function is used to print the contents of each row.
Here is an example of how to write a CSV file in Python:
In this example, a list of data is created, and the open() function is used to open the file “example.csv” in write mode. The csv.writer() function is then used to create a writer object that can be used to write the data to the CSV file. The writerows() function is used to write the data to the CSV file, and the with statement is used to automatically close the file when we are done with it.
Similar to CSV, for JSON files, you can use the json library to read and write JSON data. Here is an example of how to read a JSON file in Python:
In this example, the open() function is used to open the file “example.json” in read mode. The json.load() function is then used to read the contents of the JSON file and parse it into a Python object, in this case a dictionary. The print() function is used to print the contents of the JSON file.
Here is an example of how to write a JSON file in Python:
In this example, a dictionary of data is created and the open() function is used to open the file “example.json” in write mode. The json.dump() function is then used to write the data to the JSON file. The with statement is used to automatically close the file when we are done with it.
It’s important to note that when working with larger files you should use the with statement to open the file, as it automatically takes care of closing the file and releasing any resources held by the file.
You can also use other libraries like pandas, to work with CSV and other formats, it makes the process even more simpler and efficient.
