Python Paper 1

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 11) How to check whether a given number is Armstrong number or not

Ans: example 
       a =   153
            1*1*1 = 1
            5*5*5 = 125
            3*3*3 = 27
            1+125+27 =
        n = 153 
        if a == n :
             return Armstrong
        else 
             return Not Armstrong

        program :

        A = 153 
        temp =  A
        sum = 0
        while  temp > 0:
               digit = temp % 10
               sum += digit **3 
               temp = temp / 10

        if A == sum :
             return Armstrong
        else 
             return Not Armstrong

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12) What is indexing and negative indexing in Tuple?

my_tuple = ("apple", "banana", "cherry", "date")

# Slicing with positive indices

print(my_tuple[1:3])  # Output: ('banana', 'cherry')

# Slicing with negative indices

print(my_tuple[-3:-1])  # Output: ('banana', 'cherry')
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13) Consider a Rectangle Class. Write Python code to Check the Area of the First Rectangle is Greater than Second by Overloading ‘>’ Operator

Example :   __gt__(self, other):

program:

class Rectangle:

    def __init__(self, width, height):

        self.width = width

        self.height = height


    # Method to calculate the area of the rectangle

    def area(self):

        return self.width * self.height


    # Overloading the '>' operator to compare areas

    def __gt__(self, other):

        return self.area() > other.area()


# Creating two Rectangle objects

rect1 = Rectangle(4, 5)  # Area = 4 * 5 = 20

rect2 = Rectangle(6, 3)  # Area = 6 * 3 = 18


# Checking if the area of rect1 is greater than rect2

if rect1 > rect2:

    print("The area of the first rectangle is greater than the second.")

else:

    print("The area of the second rectangle is greater than the first.")

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14) Explain values and items method used in dictionary with example

dict.values()

Program : 
my_dict = {'name': 'Alice', 'age': 25, 'city': 'New York'}

# Using the values() method
values = my_dict.values()
print(values)  # Output: dict_values(['Alice', 25, 'New York'])

# Iterating through the values
for value in my_dict.values():
    print(value)

Output : 
dict_values(['Alice', 25, 'New York'])
Alice
25
New York


dict.items()

Program:
my_dict = {'name': 'Alice', 'age': 25, 'city': 'New York'}

# Using the items() method
items = my_dict.items()
print(items)  # Output: dict_items([('name', 'Alice'), ('age', 25), ('city', 'New York')])

# Iterating through the key-value pairs
for key, value in my_dict.items():
    print(f"Key: {key}, Value: {value}")


Output:
dict_items([('name', 'Alice'), ('age', 25), ('city', 'New York')])
Key: name, Value: Alice
Key: age, Value: 25
Key: city, Value: New York
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16) Explain in detail about Python Files, its types, functions and operations that can be performed on files with examples.

Python Files: Detailed Explanation

In Python, a file is a collection of data stored in a specific format, either on the local disk or in memory, that can be accessed or modified by a program. Python provides built-in functions and modules to work with files, allowing you to read, write, and manipulate files efficiently.

Python's file handling functions are built into the standard library, and the most commonly used one is the open() function.

Types of Files in Python

There are two major types of files based on their operations and data storage:

  1. Text Files:

    • A text file contains human-readable characters (letters, numbers, symbols).
    • The contents of text files are encoded in a specific encoding (like UTF-8 or ASCII).
    • Common text file extensions: .txt, .csv, .log.

  2. Binary Files:

    • A binary file contains non-human-readable data, such as images, videos, executables, etc.
    • The data is stored in the form of 0s and 1s (binary format).
    • Common binary file extensions: .jpg, .png, .exe, .mp3.

File Modes in Python

When working with files, Python uses different modes to define the type of operation that can be performed on the file. These modes are passed as the second argument to the open() function.

Common File Modes:

  • 'r': Read (default mode) – Opens the file for reading.
  • 'w': Write – Opens the file for writing (creates a new file if it doesn't exist, or truncates the file if it does).
  • 'a': Append – Opens the file for writing (creates a new file if it doesn't exist, or appends to the file if it does).
  • 'b': Binary – Used along with other modes (e.g., 'rb' or 'wb') to handle binary files.
  • 'x': Exclusive creation – Creates a new file, but raises an error if the file already exists.
  • 't': Text – Default mode (used for text files).
  • 'r+': Read and Write – Opens the file for both reading and writing.
  • 'w+': Write and Read – Opens the file for both reading and writing (truncates the file if it exists).
  • 'a+': Append and Read – Opens the file for both appending and reading.

Opening and Closing Files

The open() function is used to open a file, and the close() method is used to close a file once operations are complete.

# Opening a file
file = open("example.txt", "r")

# Perform file operations (e.g., reading or writing)

# Closing the file
file.close()

Important: Always close the file after performing operations to release system resources.

It’s also recommended to use the with statement, which automatically closes the file once operations are completed:

with open("example.txt", "r") as file:
    # Perform file operations (reading or writing)
    content = file.read()
    print(content)
# File is automatically closed when the block is exited


File Operations in Python

Python provides several operations that can be performed on files, such as reading, writing, and modifying file content.

1. Reading from Files

There are several methods for reading data from files:

  • read(): Reads the entire content of the file.

    with open("example.txt", "r") as file:
    content = file.read()
    print(content)

  • readline(): Reads one line from the file at a time.

    with open("example.txt", "r") as file:
    line = file.readline()
    print(line)

  • readlines(): Reads all lines from the file and returns them as a list of strings.

    with open("example.txt", "r") as file:
    lines = file.readlines()
    print(lines)

2. Writing to Files

You can write data to a file using the write() or writelines() methods:

  • write(): Writes a string to the file.

    with open("example.txt", "w") as file:
    file.write("Hello, this is a test.")

  • writelines(): Writes a list of strings to the file.

    lines = ["Hello, World!\n", "Welcome to Python.\n"]
with open("example.txt", "w") as file:
    file.writelines(lines)

3. Appending to Files

You can append data to a file using the append() mode ('a'):

with open("example.txt", "a") as file:
    file.write("Appending new content to the file.")

4. File Positioning (Seek and Tell)

  • seek(offset, whence): Moves the file pointer to a specific position.

    • offset: Number of bytes to move.
    • whence: Optional argument (default is 0):
      • 0: Start of the file.
      • 1: Current file position.
      • 2: End of the file.
    with open("example.txt", "r") as file:
    file.seek(5)  # Move to the 5th byte
    content = file.read(10)  # Read 10 bytes from that position
    print(content)

  • tell(): Returns the current position of the file pointer.

    with open("example.txt", "r") as file:
    file.seek(5)
    position = file.tell()  # Get the current position
    print(f"Current position: {position}")

5. File Removal (Deleting Files)

To remove a file, you can use the os.remove() method from the os module.

import os

# Deleting a file
os.remove("example.txt")

Example: File Operations in Action

# Writing to a file
with open("example.txt", "w") as file:
    file.write("Hello, World!\n")
    file.write("This is a test file.\n")

# Reading from the file
with open("example.txt", "r") as file:
    content = file.read()
    print("File content:\n", content)

# Appending to the file
with open("example.txt", "a") as file:
    file.write("Appending more content.\n")

# Reading after appending
with open("example.txt", "r") as file:
    content = file.read()
    print("\nFile content after appending:\n", content)

File Handling Best Practices

  1. Always close files: Use file.close() or a with statement to ensure the file is automatically closed after use.
  2. Use 'with' for better resource management: The with statement automatically handles closing the file, even if an exception occurs.
  3. Handle file exceptions: Use try-except to catch exceptions (e.g., file not found).
try:
    with open("example.txt", "r") as file:
        content = file.read()
except FileNotFoundError:
    print("The file does not exist.")

Conclusion

Python provides robust file handling capabilities for interacting with both text and binary files. Key operations such as reading, writing, appending, and moving the file pointer are all straightforward and can be easily managed using the built-in open(), read(), write(), and seek() functions. Using the with statement simplifies file handling, ensuring that files are properly closed after use.

If you have further questions or need clarification on any of the concepts, feel free to ask!










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