Q: Question 2To open a file c:\test.txt for writing, we should use the statement:fobj = open("c:\test.txt", "w")fobj = open("c:\\test.txt", "w")fobj = open(file = "c:\test.txt", "w")fobj = open(file = "c:\\test.txt", "w")

fobj = open("c:\\test.txt", "w")Reason — The syntax for 'open()' is: <file variable>/<file object or handle> = open(file_name, access_mode). Therefore, according to this syntax, fobj = open("c:\\test.txt", "w") is the correct statement to open a file for writing. The access mode "w" indicates that the file should be opened in write mode.

Question 1

Question 6Assertion (A): The readline() method reads one complete line from a text file.Reasoning (R): The readline() function can also be used to read a specified number (n) of bytes of data from a file but maximum up to the newline character (
).Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationThe readline() method in Python reads one complete line from a text file and can also be used to read a specified number (n) of bytes of data from a file up to the newline character (
).

Question 2

Question 2To open a file c:	est.txt for writing, we should use the statement:fobj = open("c:	est.txt", "w")fobj = open("c:\test.txt", "w")fobj = open(file = "c:	est.txt", "w")fobj = open(file = "c:\test.txt", "w")

Accepted Answer

fobj = open("c:\test.txt", "w")Reason — The syntax for 'open()' is: / = open(file_name, access_mode). Therefore, according to this syntax, fobj = open("c:\test.txt", "w") is the correct statement to open a file for writing. The access mode "w" indicates that the file should be opened in write mode.

Question 3

Question 4Which of the following statements is/are true?When we open a file for reading, if the file does not exist, an error occurs.When we open a file for writing, if the file does not exist, a new file is created.When we open a file for writing, if the file exists, the existing file is overwritten with the new file.All of these.

Accepted Answer

All of these.Reason — When we open a file for reading ('r' mode) that doesn't exist, Python raises an error (FileNotFoundError). When we open a file for writing ('w' mode) and the file doesn't exist, a new file is created with the specified name. If we open a file for writing ('w' mode) and the file already exists, the existing file is overwritten with the new file.

Question 4

Question 7What will be the output of the following snippet?f = None
for i in range(5):
    with open("data.txt", "w") as f:
       if i > 2:
        break
print(f.closed)TrueFalseNoneError

Accepted Answer

TrueReason — Initially, the variable f is assigned None. The code then enters a for loop that runs five times (for i in range(5)). Inside the loop, a file named "data.txt" is opened in write mode ("w") using the with statement. If the value of i is greater than 2, the loop breaks using break. After the loop breaks, the print(f.closed) statement is executed outside the with block. Since the file object f was opened within the with block, it is automatically closed when the block exits. The f.closed attribute returns True if the file is closed, which happens because of the with statement's automatic closing behavior.

Question 5

Question 1What is the difference between "w" and "a" modes?

Accepted Answer

The differences between "w" and "a" modes are:"w" mode"a" modeThe "w" mode in file opening is used for writing data to a file.The "a" mode in file opening is used for appending data to a file.If the file exists, Python will truncate existing data and over-write in the file.If the file exists, the data in the file is retained and new data being written will be appended to the end of the file.

Question 6

Question 3How are open() functions different from close() functions other than their functionality of opening and closing files?

Accepted Answer

open() functionsclose() functionsIt creates a file object, which allows to perform various operations on the file, such as reading from it, writing to it, or appending data to it.When we're done working with a file, we should always close it using the close() function to free up system resources and prevent data loss.The syntax is : file_objectname = open("filename", "mode")The syntax is : file.close()

Question 7

Question 5In which of the following file modes will the existing data of the file not be lost?rbabww + ba + bwbwb+w+r+

Accepted Answer

'rb', ab, a + b, r+Explanation'rb' — This mode opens the file for reading in binary mode. It will not erase the existing data and allows reading of the file.'ab' — This mode opens the file for appending in binary mode. It will not erase the existing data but will append new data to the end of the file.'a + b' — This mode opens the file for reading and appending. It will not erase the existing data and allows both reading from and appending to the file.'r+' — This mode opens the file for reading and writing. It will not erase the existing data and allows both reading from and writing to the file.

Question 8

Question 8What role is played by file modes in file operations? Describe the various file mode constants and their meanings.

Accepted Answer

File modes play a crucial role in file operations in Python as they determine how the file will be opened and what operations can be performed on it. Each file mode specifies whether the file should be opened for reading, writing, appending, or a combination of these operations. Additionally, file modes can distinguish between text mode and binary mode, which affects how the file data is handled.Here are the various text file mode constants in Python and their meanings:"r" — Opens the file for reading only. This is the default mode if no mode is specified."w" — Opens the file for writing only."a" — Opens the file for writing, but appends new data to the end of the file."r+" — Opens the file for both reading and writing."w+" — Opens the file for writing and reading."a+" — Opens the file for reading and appending.Here are the various binary file mode constants in Python and their meanings:"rb", "wb", "ab", "rb+", "wb+", "ab+" — These modes are similar to their corresponding text modes ("r", "w", "a", "r+", "w+", "a+"), but they operate in binary mode.

Question 9

Question 9Write a code snippet that will create an object called fileout for writing; associate it with the filename 'STRS'. The code should keep on writing strings to it as long as the user wants.

Accepted Answer

fileout = open('STRS.txt', 'w')
ans = 'y'
while ans == 'y':
    string = input("Enter a string: ")
    fileout.write(string + "
")  
    ans = input("Want to enter more strings?(y/n)...")   
fileout.close()OutputEnter a string: Hello
Want to enter more strings?(y/n)...y
Enter a string: World!
Want to enter more strings?(y/n)...n
The file "STRS.txt" includes:Hello
World!

Question 10

Question 10Explain how many file objects would you need to create to manage the following situations:(a) To process three files sequentially.(b) To merge two sorted files into a third file.

Accepted Answer

(a) To process three files sequentially — In this scenario, where we need to process three files sequentially, we would need a single file object, as we can reuse a single file object by opening then processing and closing it for each file sequentially.For example :f = open("file1.txt", "r")
# Process file 1 using f
f.close()

f = open("file2.txt", "r")
# Process file 2 using f
f.close()

f = open("file3.txt", "r")
# Process file 3 using f
f.close()Here, we are reusing the f file object three times sequentially. We start by opening file1 in read mode and store its file handle in file object f. We process file1 and close it. After that, same file object f is again reused to open file2 in read mode and process it. Similarly, for file3 also we reuse the same file object f.(b) To merge two sorted files into a third file — In this scenario, where we need to merge two sorted files into a third file, we would need three file objects, one for each input file and one for the output file. We would open each input file for reading and the output file for writing. Then, we would read data from the input files, compare the data, and write the merged data to the output file. Finally, we would close all three files after the merging operation is complete.For example :f1 = open("file1.txt", "r")
f2 = open("file2.txt", "r")
f3 = open("merged.txt", "w")
# Read line from f1
# Read line from f2
# Process lines
# Write line to f3
f1.close()
f2.close()
f3.close()

Question 11

Question 11Write the advantages of saving data in:(a) Binary form(b) Text form

Accepted Answer

(a) The advantages of saving data in binary form are as follows:Efficiency — Binary files store data in a compact binary format, which can lead to smaller file sizes compared to text-based formats. Binary form is efficient for storing raw binary data.Speed — Reading and writing binary data can be faster than text-based formats because there is no need for encoding or decoding operations.Data Integrity — Binary files preserve the exact binary representation of data without any loss of information.(b) The advantages of saving data in text form are as follows:Human Readability — Text-based formats, such as plain text files, are human-readable, making them easy to inspect and edit using a text editor.Interoperability — Text files can be easily shared and processed across different platforms and programming languages.Compatibility — Text-based formats are widely supported by various software applications and systems, making them a versatile choice for data interchange and communication.

Question 12

Question 12Why is it required to close a file after performing the reading and writing operations on a file?

Accepted Answer

It is a good practice to close a file once we are done with the read and write operations. When we close a file, the system frees the memory allocated to it. Python ensures that any unwritten or unsaved data is flushed (written) to the file before it is closed. Therefore, it is always advised to close the file once our work is done.

Question 13

Question 13When do you think text files should be preferred over binary files?

Accepted Answer

Text files should be preferred over binary files when dealing with human-readable data that does not require special encoding or formatting. They are ideal for storing plain text, such as configuration files, logs, or documents, as they are easily editable and can be viewed using a simple text editor. Text files are also more portable and platform-independent, making them suitable for data interchange between different systems.

Question 14

Question 14Write a program that reads a text file and creates another file that is identical except that every sequence of consecutive blank spaces is replaced by a single space.

Accepted Answer

Let the file "input.txt" include the following sample text:In   the beginning  there  was    chaos.
Out of  the chaos  came order.
The universe  began to take shape.
Stars  formed  and galaxies were  born.
Life   emerged  in the  vast  expanse.
with open("input.txt", 'r') as f:
    with open("output.txt", 'w') as fout:
        for line in f:
            modified_line = ' '.join(line.split())
            fout.write(modified_line + '
')The file "output.txt" includes following text:In the beginning there was chaos.
Out of the chaos came order.
The universe began to take shape.
Stars formed and galaxies were born.
Life emerged in the vast expanse.

Question 15

Question 15A file 'sports.dat' contains information in the following format: EventName, ParticipantWrite a function that would read contents from file 'sports.dat' and create a file named 'Athletic.dat' copying only those records from 'sports.dat' where the event name is "Athletics".

Accepted Answer

Let the file "sports.dat" include the following sample records:Athletics - Rahul
Swimming - Tanvi
Athletics - Akash
Cycling - Kabir
Athletics - Riya
def filter_records(input_file, output_file):
    with open(input_file, 'r') as f_in:
        with open(output_file, 'w') as f_out:
            for line in f_in:
                event, participant = line.strip().split(' - ')
                if event == 'Athletics':
                    f_out.write(line)

filter_records('sports.dat', 'Athletic.dat')The file "Atheletic.dat" includes following records:Athletics - Rahul
Athletics - Akash
Athletics - Riya

Question 16

Question 16Write a program to count the words "to" and "the" present in a text file "Poem.txt".

Accepted Answer

Let the file "Poem.txt" include the following sample text:To be or not to be, that is the question.
The quick brown fox jumps over the lazy dog.
To infinity and beyond!
The sun sets in the west.
To be successful, one must work hard.
to_count = 0
the_count = 0

with open("Poem.txt", 'r') as file:
    for line in file:
        words = line.split()
        for word in words:
            if word.lower() == 'to':
                to_count += 1
            elif word.lower() == 'the':
                the_count += 1

print("count of 'to': ", to_count)
print("count of 'the': ", the_count)Outputcount of 'to': 4
count of 'the': 5

Question 17

Question 17Write a program to count the number of uppercase alphabets present in a text file "Poem.txt".

Accepted Answer

Let the file "Poem.txt" include the following sample text:PYTHON is a Popular Programming Language.
with open("Poem.txt", 'r') as file:
    text = file.read()
    count = 0
    for char in text:
        if char.isupper():
            count += 1

print(count)Output9

Question 18

Question 18Write a program that copies one file to another. Have the program read the file names from user.

Accepted Answer

def copy_file(file1, file2):
    with open(file1, 'r') as source:
        with open(file2, 'w') as destination:
            destination.write(source.read())
    
source_file = input("Enter the name of the source file: ")
destination_file = input("Enter the name of the destination file: ")

copy_file(source_file, destination_file)

Question 19

Question 19Write a program that appends the contents of one file to another. Have the program take the file names from the user.

Accepted Answer

def append_file(f1, f2):
    with open(f1, 'r') as source:
        with open(f2, 'a') as destination:
            destination.write(source.read())
    
source_file = input("Enter the name of the source file: ")
destination_file = input("Enter the name of the destination file: ")

append_file(source_file, destination_file)

Question 20

Question 20Write a program that reads characters from the keyboard one by one. All lower case characters get stored inside the file 'LOWER', all upper case characters get stored inside the file 'UPPER' and all other characters get stored inside file 'OTHERS'.

Accepted Answer

lower_file = open("LOWER.txt", 'w')
upper_file = open("UPPER.txt", 'w')
others_file = open("OTHERS.txt", 'w')
ans = 'y'
while ans == 'y':
    char = input("Enter a character: ")
    if char.islower():
        lower_file.write(char + "
")
    elif char.isupper():
        upper_file.write(char + "
")
    else:
        others_file.write(char + "
")
    ans = input("Want to enter a character? (y/n): ")
lower_file.close()
upper_file.close()
others_file.close()OutputEnter a character: e
Want to enter a character? (y/n): y
Enter a character: A
Want to enter a character? (y/n): y
Enter a character: D
Want to enter a character? (y/n): y
Enter a character: c
Want to enter a character? (y/n): y
Enter a character: 7
Want to enter a character? (y/n): y
Enter a character: @
Want to enter a character? (y/n): n
The file "LOWER.txt" includes:e
c
The file "UPPER.txt" includes:A
D
The file "OTHERS.txt" includes:7
@

Data File Handling

Assertions And Reasons

Multiple Choice Questions

Solutions To Unsolved Questions