Python Data Science Interview Questions

 Python Interview Questions and Answers

1. What are the data types used in Python?

Python has following list of data types:                          

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• List, Set and Dictionary are mutable that means they can be modified during runtime.
• Number, String and Tuples are immutable that means they can not be modified during runtime.

2. Explain difference between List ,Tuples, Set and Dictionary.

3. What is Python Dictionary ?

• A built in data types and defined as unordered mapping of unique keys to values.
• Dictionary is indexed by Keys and Values can be any inbuilt data type or user defined class.
• Dictionary is mutable that means it can be modified during run time.
• Dictionary is created with curly braces {}. Ex: my_dict = {'name':  'kaushal',  'age': 50}
• Dictionary is index by square bracket []. Ex: my_dict['age'] = 50

      

         English Dictionary vs Python Dictionary : Concept

Python Dictionary Example:                                                                                          

                                                                                                            

4. What is different method and operation in python Dictionary ? 

Example :   

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5. What are lambda function ?

• Lambda are anonymous function in python.
• They are very helpful when you need to define a function that's very short and consist only one expression.
•  Instead of creating a small function with Name, argument, expression and return statement you can write everything in one liner code using Lambda function

          

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• Example : (lambda x, y, x: (x+y) **z) (2,3,4) , Output: 625

5. Explain List comprehensions and how they are used in python ?

•   List comprehensions is concise way to create the list.
•   List are traditionally created within square bracket [].
•   List comprehensions add expression within these bracket followed by  a For clause and then IF clause ( when necessary)
•   Evaluating the given expression with For Clause with IF clause produces a List.
• Example: a_list = [1,2,4,5,0,-2] , C_list = [x**2 for x in a_list if x>0] , Output: [1,4,16,25]
• Trick to Remember :  For x in a_list:            
•                                             if ( x > 0) :
•                                                 print(x**2)
• 
  
  
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