BCA PART A 10. Read and write into a file

 

def write_to_file(filename, data):

"""

Write data to a file.

Parameters:

filename (str): The name of the file to write to.

data (str): The data to write into the file.

"""

with open(filename, 'w') as file:

file.write(data)

print(f"Data written to file '{filename}' successfully.")

def read_from_file(filename):

"""

Read data from a file.

Parameters:

filename (str): The name of the file to read from.

Returns:

str: The data read from the file.

"""

with open(filename, 'r') as file:

data = file.read()

print(f"Data read from file '{filename}':")

return data

if __name__ == '__main__':

filename = input("Enter the name of the file: ")

# User choice for operation

print("\nChoose an operation:")

print("1. Write to the file")

print("2. Read from the file")

choice = input("Enter your choice (1/2): ")

if choice == '1':

# Writing to the file

data_to_write = input("Enter the data to write into the file: ")

write_to_file(filename, data_to_write)

elif choice == '2':

# Reading from the file

data = read_from_file(filename)

print(data)

else:

print("Invalid choice. Please enter 1 or 2.")

Output :

Enter the name of the file: test Choose an operation: 1. Write to the file 2. Read from the file Enter your choice (1/2): 1 Enter the data to write into the file: Good Morning. Welcome to Vidya Vikas Data written to file 'test' successfully.

Enter the name of the file: test Choose an operation: 1. Write to the file 2. Read from the file Enter your choice (1/2): 2 Data read from file 'test': Good Morning. Welcome to Vidya Vikas

Explanation :

In this program, two functions are defined:

• write_to_file:

  • Takes a filename and data as input.
  • Opens the file in write mode ('w'), which either creates the file if it doesn't exist or truncates the file if it already exists.
  • Writes the data to the file.
  • Closes the file automatically when the with block exits.

• read_from_file:

  • Takes a filename as input.
  • Opens the file in read mode ('r').
  • Reads the data from the file.
  • Closes the file automatically when the with block exits.
  • Returns the data read from the file.

In the example usage section of the program:

• The user is prompted to enter the filename.
• The user chooses to either write to the file or read from it.
• Depending on the user's choice:
  • For the write operation, the program prompts the user to enter the data to write to the file and then calls the write_to_file function.
  • For the read operation, the program calls the read_from_file function and prints the data read from the file.