eof when reading a line

The "EOF when reading a line" error (EOFError) occurs in Python when the input() function encounters an end-of-file (EOF) condition without reading any data. This typically happens in these scenarios:

• When using input() interactively but no input is provided.
• When reading lines from a file or stream and attempting to read beyond the end of the file.
• When code execution is interrupted (e.g., using Ctrl+D in Linux or macOS) while input() is waiting for input.
• When input() is called inside a loop expecting continuous input but none is given at some iteration.

It means the program expected more input, but it reached the end of the input source instead. To handle this, one common approach is to use a try-except block around input() to catch the EOFError and handle it gracefully, for example by providing a default value or breaking out of a loop. Example to handle EOFError in a loop reading lines until EOF:

python

while True:
    try:
        line = input("Enter something: ")
    except EOFError:
        break
    print(f"You entered: {line}")

When reading lines from a file, you can avoid EOFError by checking whether you've reached the end of the file before trying to read:

python

with open('file.txt', 'r') as file:
    while True:
        line = file.readline()
        if not line:
            break
        print(line.strip())

In summary, EOFError "EOF when reading a line" happens when Python expects input but reaches the end of file/input stream unexpectedly. Handling it requires anticipating the EOF condition and using try-except blocks or proper checks to avoid trying to read beyond input availability.