Reading And Writing Files

Exercise: Reading And Writing Files

What is the purpose of the os.path.join() function in Python when working with file paths?

To create a new file

To concatenate multiple file paths

To check if a file exists

To rename a file

Answer: B

os.path.join() is used to concatenate multiple file paths and create a valid path.

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How can you write a dictionary to a file named "data.json" in JSON format?

write_json("data.json", {"key": "value"})

json.write("data.json", {"key": "value"})

with open("data.json", "w") as file:
    json.dump({"key": "value"}, file)

file.write_json("data.json", {"key": "value"})

Answer: C

Using json.dump() to write a dictionary to a JSON file.

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What is the purpose of the truncate() method when working with files?

To remove all contents of the file

To shorten the file name

To create a new file

To split the file into multiple parts

Answer: A

The truncate() method is used to remove all contents of the file from the current position.

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Which method is used to check if a file object is in a valid state?

validate()

check()

is_valid()

closed()

Answer: D

The closed() method checks if a file object is in a valid state (closed or not).

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How can you read and print only the even-numbered lines from a file named "numbers.txt"?

even_lines = open("numbers.txt").readlines()[1::2]
    for line in even_lines:
    print(line)

with open("numbers.txt", "r") as file:
    lines = file.readlines()
    for i in range(1, len(lines), 2):
        print(lines[i])

even_numbers("numbers.txt")

read_even("numbers.txt")

Answer: A

Using list slicing to select even-numbered lines and then printing them.

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