Python top interview questions and answers

 

Python top 25 interview questions and answer

 

1.    

 1. What is Python?

Ans: Python is a high-level, interpreted, general-purpose programming language. It was created by         Guido van Rossum in the late 1980s and was first released in 1991.

 

2.      2.  What are the key features of Python?

Ans : Some of the key features of Python include its simple and easy-to-learn syntax, dynamic             semantics, interpreted nature, and support for multiple programming paradigms, such as object-oriented, imperative, and functional programming.

 

3.      3. What are the different data types in Python?

Ans:Python has several built-in data types, including integers, floating-point numbers, strings, lists, tuples, and dictionaries.

 

4.      4. How does Python handle memory management?

Python uses a private heap space to manage memory. The memory manager in Python is responsible for allocating and deallocating memory for Python objects. The interpreter periodically runs a garbage collector to free up memory that is no longer being used by the program.

 

5.      5. What is a tuple in Python?

A tuple is a collection of ordered and immutable elements. They are enclosed in round brackets or parentheses.

 

6.     6.  What is a list comprehension in Python?

List comprehension is a concise and memory-efficient way to create a new list in Python by applying a certain operation to each element in an existing list or other iterable.

 

7.      7. How can you create a dictionary in Python?

A dictionary in Python is created by placing a comma-separated list of key-value pairs within curly braces {}. The keys must be unique and immutable, while the values can be of any type.

 

8.     8.  How can you check if a variable is of a certain data type in Python?

You can use the built-in function type() to check the data type of a variable in Python.

 

9.      9. What is a decorator in Python?

A decorator is a design pattern in Python that allows you to add new functionality to an existing function or class without modifying its source code. Decorators are defined using the "@" symbol.

 

10.   10 .What is the difference between a deep copy and a shallow copy in Python?

A shallow copy creates a new object that stores a reference to the original object, while a deep copy creates a new object with a new memory address and copies the values of the original object into it.

 

 

11.   11. What is a generator in Python?

A generator is a special type of iterator in Python that allows you to iterate over a sequence of items without loading all of them into memory at once. You can define a generator using the "yield" keyword.

 

12.  12.  What is the difference between a list and an array in Python?

A list is a built-in Python data structure that can hold a collection of items of any type, while an array is a more efficient data structure that can hold items of a specific type, typically numbers. The array module in Python provides an array() function to create arrays, but they are less flexible than lists.

 

13.  13.  What is the use of the "with" statement in Python?

The "with" statement in Python is used to wrap the execution of a block of code with methods defined by a context manager. It automatically handles the setup and cleanup of resources, such as file handles, sockets, and database connections, and it can simplify error handling.

 

14.  14.  How can you sort a list in Python?

You can use the built-in sort() method to sort a list in Python. This method modifies the list in place and returns None. You can also use the sorted() function to create a new sorted list from an iterable.

 

15.   15. What is a namespace in Python?

A namespace is a container that holds a set of identifiers, such as variable names and function names, and maps them to their corresponding values or objects. In Python, a namespace is a dictionary-like object that stores the mapping of names to objects.

 

16. 16.   How can you remove duplicates from a list in Python?

You can use the set() function to remove duplicates from a list in Python. This function creates a new set object, which only contains unique elements, and then you can convert it back to a list using the list() function.

 

17. 17.   What is the difference between a global variable and a local variable in Python?

A global variable is a variable that is defined outside of any function or class and can be accessed from anywhere in the code. A local variable is a variable that is defined inside a function or class and can only be accessed from within that scope.

 

18.  18.  How can you convert a string to an int in Python?

You can use the built-in int() function to convert a string to an int in Python. This function takes a string as its argument and returns an int object.

 

19.   19. How can you check if a key exists in a dictionary in Python?

You can use the "in" operator to check if a key exists in a dictionary in Python. This operator returns a Boolean value indicating whether the specified key is present in the dictionary.

 

20. 20  What is the use of the "raise" statement in Python?

The "raise" statement in Python is used to raise an exception. This statement can be used to indicate that an error has occurred, or to create custom exceptions. It can be used along with try-except block to handle the exception.

 

21 21. What is a lambda function in Python?

A lambda function is a small, anonymous function that can be defined without a name. It is defined using the lambda keyword, followed by a list of arguments, a colon, and a single expression. Lambda functions are often used as arguments to higher-order functions, such as map() and filter().

 

22.  22.  How can you create a module in Python?

A module in Python is a collection of Python code that can be reused in multiple scripts. You can create a module by writing Python code in a file with a .py extension. The module can be imported using the import statement and the name of the file without the .py extension.

 

23.   23. How can you check if a string contains a substring in Python?

You can use the "in" operator to check if a string contains a substring in Python. This operator returns a Boolean value indicating whether the substring is present in the string. You can also use the str.find() method to check for the presence of a substring, which returns the index of the first occurrence of the substring in the string, or -1 if not found.

 

24.   24. What is the difference between the "==" and "is" operators in Python?

The "==" operator compares the values of two objects and returns a Boolean value indicating whether they are equal or not. The "is" operator compares the memory addresses of two objects and returns a Boolean value indicating whether they are the same object or not.

 

2525.   How can you reverse a string in Python?

You can use the slicing technique to reverse a string in Python. To do this, you can use the string followed by [-1] to slice the string in reverse order. Or you can use the built-in function 'reversed()' to reverse the string and convert it back to string using 'join()' method.