Q1 In some languages, every statement ends with a semi-colon
(;). What happens if you put a semi-colon at the end of a Python
statement? [ 2019-20]
Python, the use of a semi-colon (;) is optional, and it is not required to
If you add a
semi-colon at the end of a Python statement, it will not produce any error, and
the program will execute correctly. However, it is considered unnecessary and
unusual in Python coding conventions, and it may make your code harder to read
and understand for other developers.
the semi-colon is used to terminate statements, in Python, the end of the line
indicates the end of a statement. Therefore, Python interprets a new line as
the end of the statement, and there’s no need to use a semi-colon.
adding semi-colons at the end of Python statements is not necessary, and it’s
best to follow the Python coding conventions and avoid using them unless you
have a specific reason to do so.
Q2 Mention five benefits of using
Python. [ 2019-20]
Solution: here are
five benefits of using Python:
excellent choice for beginners to programming. The language’s simplicity also
reduces the time and effort needed to develop and maintain code.
2. Large standard library: Python has an extensive standard library that includes modules for a
wide range of tasks such as working with regular expressions, network
programming, and database access. These libraries help to speed up development
by providing pre-written code that can be reused in your projects.
compatibility: Python is a cross-platform language, which means
that code written on one platform (e.g., Windows) can be easily run on another
platform (e.g., Linux or macOS) without making any changes. This feature makes
Python a versatile language for developing applications that need to run on
4. High-level language: Python is a high-level language that takes care of memory management
and other low-level tasks, which means that developers can focus on writing the
code and solving problems rather than worrying about memory allocation and
other system details.
5. Large community support: Python has a large and active community of developers who contribute to
the language’s development by creating new libraries, improving documentation,
and providing support to new users. This community ensures that Python is
continuously evolving and improving, making it a reliable and popular choice
for many applications.
Q3 How is Python an interpreted language? [ 2019-20]
Solution: Python is an
interpreted language because it does not require compilation before execution.
In a compiled language like C or Java, the source code is converted into
machine code (binary code) by a compiler, which can then be executed directly
by the computer.
an interpreted language like Python, the source code is executed line by line
by an interpreter. The interpreter reads and executes the source code directly,
without the need for compilation into binary code.
When a Python
program is executed, the interpreter first reads the code, checks for syntax
errors, and then executes the code line by line. The interpreter translates
each statement in the code into bytecode, which is an intermediate form of the
code that is then executed by the Python Virtual Machine (PVM).
of interpreting the code is slower than running a compiled program, but it
allows for greater flexibility and faster development. Interpreted languages
like Python are also often easier to debug since errors can be identified and
corrected as the code is being executed.
Python’s interpreted nature makes it a popular choice for scripting, rapid
prototyping, and application development where flexibility and speed of
development are essential.
Q4 What type of language is python? [ 2019-20]
Solution: Python is a high-level, general-purpose programming
language. It was created by Guido van Rossum and released in 1991. Python
is designed to be easy to read and write, with a simple and consistent syntax
that emphasizes readability and reduces the cost of program maintenance.
Python is an interpreted language, which means that
it does not require compilation before execution, and it can be run on a
variety of platforms, including Windows, macOS, and Linux.
also an object-oriented language,
meaning that it supports the creation and manipulation of objects, which are
instances of classes. It also supports functional programming, which means that
it allows for the creation and manipulation of functions as first-class
used in a wide range of applications, including web development, data science,
machine learning, scientific computing, and game development. Its versatility,
ease of use, and large community of users and developers make it a popular
choice for a wide range of programming tasks.
Q5 What are local variables and global
variables in Python? [ 2019-20]
Solution:In Python, variables are used to store values that can be manipulated or used in a program. Python variables can be divided into two types: local variables and global variables.
Local variables are variables that are defined within a function or a block of code. These variables are only accessible within the function or block of code in which they are defined. Once the function or block of code is exited, the local variables are destroyed, and their values are no longer accessible. Local variables are useful for storing temporary values that are only needed within a specific function or block of code.
Here is an example of a local variable:
def multiply(x, y):
result = x * y
# ‘result’ is a local variable that is only accessible within the ‘multiply’ function
Global variables, on the other hand, are variables that are defined outside of a function or block of code. These variables can be accessed from any part of the program, including inside functions or blocks of code. Global variables are useful for storing values that need to be accessed from multiple parts of the program.
Here is an example of a global variable:
count = 0 # ‘count’ is a global variable
global count # use ‘global’ keyword to access global variable inside a function
count += 1
# ‘count’ can be accessed from both inside and outside the ‘increment_count’ function
It is important to be careful when using global variables, as they can be modified from any part of the program and can cause unintended side effects.
Q6 Define floor division with
example. [ 2019-20]
Solution: In Python, floor division is a type of division operation that returns the largest whole number that is less than or equal to the result of dividing two numbers. The floor division operator in Python is represented by two forward slashes (//).
Here is an example of floor division in Python:
# Floor division of two integers
a = 15
b = 2
result = a // b
print(result) # Output: 7
# Floor division of a float and an integer
c = 8.5
d = 2
result2 = c // d
print(result2) # Output: 4.0
# Floor division of two floats
e = 10.0
f = 3.0
result3 = e // f
print(result3) # Output: 3.0
In the first example, the result of the floor division operation between 15 and 2 is 7, since 15 divided by 2 equals 7.5, and the largest whole number less than or equal to 7.5 is 7.
In the second example, the result of the floor division operation between 8.5 and 2 is 4.0, since 8.5 divided by 2 equals 4.25, and the largest whole number less than or equal to 4.25 is 4.
In the third example, the result of the floor division operation between 10.0 and 3.0 is 3.0, since 10.0 divided by 3.0 equals 3.333…, and the largest whole number less than or equal to 3.333… is 3.
Q7 Which of the following statements produce an error in python?
X, y, z = 1,2,3 #S1
A,b = 4,5,6 #S2
U = 7,8,9, 3 #S3
statement that would produce an error in Python is “A, b = 4, 5, 6”
because Python will attempt to unpack the values “4, 5, 6” into two
variables “A” and “b”, but it will fail because there are
more values (3) than variables (2). This will result in a “ValueError: too
many values to unpack” error.
On the other
hand, statement S1 assigns three values to three variables, and statement S3
assigns four values to a single variable, which is valid in Python.
Q8 What is the role of precedence with example? [ 2020-2021]
programming, precedence refers to the order in which operators are evaluated in
an expression. The precedence rules determine which operation is performed
first in a complex expression.
in the expression 2 + 3 * 4, the multiplication operator (*) has a higher
precedence than the addition operator (+). So, the expression is evaluated as 2
+ (3 * 4), which results in 14.
example that shows how precedence can affect the result of an expression:
x = 5
y = 2
z = 1
result = x –
y * z
example, the multiplication operator has a higher precedence than the
subtraction operator, so the expression is evaluated as x – (y * z). This
results in x – 2, which is equal to 3.
If we want to
change the order of evaluation, we can use parentheses to explicitly specify
the precedence, like this:
result = (x –
y) * z
In this case,
the subtraction operator has a higher precedence than the multiplication
operator because of the parentheses, so the expression is evaluated as (x – y)
* z. This results in 6.
understanding the rules of precedence and using parentheses when necessary, we
can ensure that our expressions are evaluated correctly and produce the desired
integer in the rest of the program? explain with an example.
you can read input from a user and convert it to an integer using the input()
and int() functions. Here is an example:
user to enter a number
input(“Enter a number: “)
input to an integer
some calculations with the integer
num_int * 2
result is:”, result)
example, the input() function is used to prompt the user to enter a number,
which is then stored in the num_str variable as a string.
int() function is used to convert the string to an integer, which is stored in
the num_int variable.
value stored in num_int is then used to perform some calculations (doubling the
value in this case), and the result is stored in the result variable.
print() function is used to display the result to the user.
the user enters something that cannot be converted to an integer (e.g. a string
or a floating-point number), a ValueError will be raised when the int()
function is called. To handle this case, you can use a try-except block to
catch the exception and prompt the user to enter a valid integer.
Q10 Explain the Programming Cycle for
Python in detail.
Solution: The programming cycle is a series of steps that programmers follow to develop software solutions. The programming cycle for Python includes the following steps:
Problem analysis: This is the first step in the programming cycle, where the programmer analyzes the problem statement to determine the requirements of the software solution. The programmer identifies the inputs, outputs, processing steps, and any other constraints or special requirements for the software.
Algorithm design: In this step, the programmer designs an algorithm or set of instructions that will accomplish the processing steps required to solve the problem. This involves breaking down the problem into smaller, manageable tasks that can be coded into a program.
Coding: This is where the programmer writes the actual code for the program in the Python programming language, using the algorithm designed in the previous step as a guide.
Debugging: Once the program is coded, the programmer tests it for errors, called bugs, and makes corrections as necessary. The programmer may use debugging tools and techniques to identify and fix any errors in the program.
Testing: In this step, the programmer tests the program to ensure that it works correctly and meets the requirements identified in the problem analysis step. The programmer may use test cases or user scenarios to validate the program’s functionality.
Maintenance: After the program has been tested and deployed, the programmer may need to provide ongoing maintenance and support to ensure that the program continues to function correctly and meet the needs of its users. This may involve fixing bugs, adding new features or functionality, or making other changes to the program over time.
Overall, the programming cycle for Python involves a series of steps that begin with problem analysis and end with maintenance and support. Each step is essential for developing a successful software solution and requires careful planning, design, and execution.
Q11 Can we make multiline comments in
Solution: Yes, we can make multiline comments in Python using either triple single quotes or triple double quotes. This is also known as a documentation string or docstring. The docstring is used to describe the purpose of a module, function, class, or method in Python.
Here’s an example of how to create a multiline comment in Python using triple single quotes:
This is a multiline comment in Python.
This is the second line of the comment.
This is the third line of the comment.
Here’s an example of how to create a multiline comment in Python using triple double quotes:
This is a multiline comment in Python.
This is the second line of the comment.
This is the third line of the comment.
It’s important to note that while these docstrings can be used as comments, they can also be used for documentation purposes. In fact, it’s a recommended best practice to include docstrings in your Python code to help others understand the purpose of your code and how to use it.
Q12 What are the difference between
Java and Python ?
Solution: Java and Python are both popular programming languages, but they have some differences in their syntax, features, and use cases. Here are some of the main differences between Java and Python:
Syntax: Java has a more verbose syntax compared to Python. Java code requires more lines of code to accomplish a task than Python. Python uses indentation for block structure, while Java uses curly braces.
Type system: Java is a strongly-typed language, meaning that every variable must be declared with its data type. Python is a dynamically-typed language, meaning that variable types are determined at runtime.
Performance: Java is generally faster than Python because it is a compiled language, whereas Python is an interpreted language. However, Python’s performance can be improved with the use of libraries such as NumPy and Pandas.
Application: Java is commonly used for developing large-scale applications, such as enterprise software and Android apps. Python is commonly used for data analysis, scientific computing, artificial intelligence, and web development.
Memory management: Java uses automatic garbage collection to manage memory, whereas Python uses reference counting and garbage collection.
Community: Both Java and Python have large and active communities, with a wealth of resources and support available. However, Python’s community is known for its friendliness and accessibility, making it easier for beginners to learn and get involved.
In summary, while both Java and Python are powerful programming languages, they differ in their syntax, type system, performance, application, memory management, and community. The choice between Java and Python ultimately depends on the specific needs and goals of the project or application being developed.
Q13 What are the features of Python ?
Solution: Python is a popular programming language that is known for its simplicity, versatility, and flexibility. Here are some of the key features of Python:
- Easy to learn: Python has a simple and easy-to-learn syntax, which makes it an ideal language for beginners.
- Interpreted: Python is an interpreted language, which means that the code is executed line-by-line at runtime.
- Dynamically-typed: Python is a dynamically-typed language, which means that variable types are determined at runtime.
- High-level: Python is a high-level language, which means that it abstracts away many low-level details of the underlying hardware, making it easier to write code.
- Object-oriented: Python supports object-oriented programming (OOP) concepts, such as encapsulation, inheritance, and polymorphism.
- Extensive standard library: Python comes with a large standard library that provides many built-in functions and modules that can be used for a variety of tasks.
- Cross-platform: Python is a cross-platform language, which means that code written on one operating system can be easily ported to another operating system.
- Large and active community: Python has a large and active community of developers, who contribute to a wealth of resources, documentation, and support.
- Third-party libraries: Python has a vast ecosystem of third-party libraries, such as NumPy, Pandas, and TensorFlow, which provide additional functionality for data analysis, machine learning, and scientific computing.
Overall, Python’s simplicity, versatility, and flexibility make it a popular choice for a wide range of applications, from web development to data analysis to scientific computing.
Q14 Which character is used for
commenting in Python ?
Solution: In Python, the hash character (#) is used for commenting. Any text that follows a hash character in a Python script is considered a comment and is ignored by the Python interpreter. Comments are used to provide explanations and context for the code, or to temporarily disable code that is not needed.
# This is a comment in Python
print(“Hello, World!”) # This is another comment
In the above example, the first line is a comment, and the second line is a Python statement that will print the string “Hello, World!” to the console. The third line is also a comment, but it follows the Python statement instead of being on its own line.
Q15 Define the type () function?
Solution: The type() function in Python is a built-in function that is used to determine the type of an object.
The object parameter can be any Python object such as an integer, string, list, tuple, function, etc. The type() function returns the type of the object as a string.
x = 5
print(type(x)) # Output: <class ‘int’>
y = “Hello”
print(type(y)) # Output: <class ‘str’>
z = [1, 2, 3]
print(type(z)) # Output: <class ‘list’>
In the above example, type() is used to determine the type of the variables x, y, and z. The output shows that x is an int, y is a str, and z is a list.
Q16 Define the unary operator?
Solution: In programming, a unary operator is an operator that takes a single operand or argument and performs an operation on it. Unary operators are commonly used in programming languages to perform various types of operations on variables, constants, and expressions.
Examples of unary operators include:
Unary plus (+): This operator simply returns the value of the operand with a positive sign.
Unary minus (-): This operator returns the negative value of the operand.
Logical NOT (!): This operator reverses the logical value of the operand. If the operand is True, it returns False, and if the operand is False, it returns True.
Bitwise NOT (~): This operator performs a bitwise NOT operation on the operand. It flips all the bits of the operand.
Type conversion operators: These operators are used to convert the type of the operand into another type. For example, the int() function can be used to convert a string or float value into an integer.
Unary operators are important in programming as they allow us to perform various types of operations on variables and expressions with a single operator, making our code more concise and efficient.
Q17 What is the purpose of PYTHONPATH
environment variable ?
Solution: The PYTHONPATH environment variable is used in Python to specify a list of directories where Python modules should be searched for by the interpreter.
When you import a module in Python, the interpreter looks for the module in the directories listed in the sys.path list. The PYTHONPATH environment variable allows you to add additional directories to this list, so that you can import modules from those directories.
For example, let’s say you have a custom Python module called my_module.py that is stored in /home/user/my_project/. If you want to use this module in another Python script, you can set the PYTHONPATH environment variable to include /home/user/my_project/, like this:
$ export PYTHONPATH=/home/user/my_project/
Now, when you run your Python script that imports my_module.py, the interpreter will search for the module in the directories listed in sys.path, which includes the directory you added to PYTHONPATH.
Note that you can include multiple directories in PYTHONPATH by separating them with a colon (:) on Linux/Unix/Mac or semicolon (;) on Windows.
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