Python Interview Questions Set 5

Intermediate Level

What is init in Python?

init methodology is a reserved method in Python aka constructor in OOP. When an object is created from a class and init methodology is called to access the class attributes.

What are the tools present to perform static analysis?

The two static analysis tools used to find bugs in Python are Pychecker and Pylint. Pychecker detects bugs from the source code and warns about its style and complexity. While Pylint checks whether the module matches up to a coding standard.

What is pass in Python?

Pass is a statement that does nothing when executed. In other words, it is a Null statement. This statement is not ignored by the interpreter, but the statement results in no operation. It is used when you do not want any command to execute but a statement is required.

How can an object be copied in Python?

Not all objects can be copied in Python, but most can. We can use the “=” operator to copy an object to a variable. ex: var=copy.copy(obj)

How can a number be converted to a string?

The inbuilt function str() can be used to convert a number to a string.

What are modules and packages in Python?

Modules are the way to structure a program. Each Python program file is a module, importing other attributes and objects. The folder of a program is a package of modules. A package can have modules or subfolders.

What is the object() function in Python?

In Python, the object() function returns an empty object. New properties or methods cannot be added to this object.

What is the difference between NumPy and SciPy?

NumPy stands for Numerical Python while SciPy stands for Scientific Python. NumPy is the basic library for defining arrays and simple mathematical problems, while SciPy is used for more complex problems like numerical integration and optimization and machine learning and so on.

Define encapsulation in Python?

Encapsulation means binding the code and the data together. A Python class for example.

What is the type () in Python?

type() is a built-in method that either returns the type of the object or returns a new type of object based on the arguments passed. ex: a = 100 type(a) o/p: int

What is the split() function used for?

Split function is used to split a string into shorter strings using defined separators. letters= ('' A, B, C”) n = text.split(“,”) print(n) o/p: [‘A’, ‘B’, ‘C’ ]

What are the built-in types does python provide?

Python has following built-in data types: Numbers: Python identifies three types of numbers: 1. Integer: All positive and negative numbers without a fractional part 2. Float: Any real number with floating-point representation 3. Complex numbers: A number with a real and imaginary component represented as x+yj. x and y are floats and j is 1(square root of -1 called an imaginary number) Boolean: The Boolean data type is a data type that has one of two possible values i.e. True or False. Note that ‘T’ and ‘F’ are capital letters. String: A string value is a collection of one or more characters put in single, double or triple quotes. List: A list object is an ordered collection of one or more data items that can be of different types, put in square brackets. A list is mutable and thus can be modified, we can add, edit or delete individual elements in a list. Set: An unordered collection of unique objects enclosed in curly brackets Frozen set: They are like a set but immutable, which means we cannot modify their values once they are created. Dictionary: A dictionary object is unordered in which there is a key associated with each value and we can access each value through its key. A collection of such pairs is enclosed in curly brackets. For example {‘First Name’: ’Tom’, ’last name’: ’Hardy’} Note that Number values, strings, and tuples are immutable while List or Dictionary objects are mutable.

What is docstring in Python?

Python docstrings are the string literals enclosed in triple quotes that appear right after the definition of a function, method, class, or module. These are generally used to describe the functionality of a particular function, method, class, or module. We can access these docstrings using the doc attribute. Here is an example: def square(n): '''Takes in a number n, returns the square of n''' return n**2 print(square.__doc__) Ouput: Takes in a number n, returns the square of n

How to Reverse a String in Python?

In Python, there are no in-built functions that help us reverse a string. We need to make use of an array slicing operation for the same. str_reverse = string[::-1]