Create data_science_interviews.md

Author: devAmoghS

data_science_interviews.md

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+What is PEP 8 and why is it important? 
+
+What is Scope in Python? 
+
+What are lists and tuples? What is the key difference between the two? 
+
+What are modules and packages in Python? 
+
+What is self in Python?  
+
+What are decorators in Python?  
+
+What is lambda in Python? Why is it used?  
+
+What are generators in Python?  
+
+Can you create a series from the dictionary object in pandas? 
+
+ How will you delete indices, rows, and columns from a data frame?  
+
+ Can you get items of series A that are not available in another series B?  
+
+How are NumPy arrays advantageous over python lists?  
+
+Write python function which takes a variable number of arguments.  
+
+WAP (Write a program) which takes a sequence of numbers and checks if all numbers are unique.
+
+****************************************************************************
+
+How do we use Eigenvalues and eigenvectors in PCA (Principal Components Analysis) ?
+
+Difference between exogenous and auto regression in time series forecasting. 
+
+Difference between normalization and standardization, will it be used before train test split or after? 
+
+How to reduce the impact of one feature than others 
+
+Difference between XGBoost and FBProphet. 
+
+Describe the scenario where you do not make stationery data in time series forecasting problem 
+
+BERT is trained on which dataset? What model will be used if BERT does not exist? Describe self- attention mechanism. 
+
+Difference between univariate and multivariate time series forecasting problems. 
+****************************************************************************
+
+Find the middle node of a given LinkedList. 
+`Used two pointer approach` 
+`Slow Pointer = node.next`, and 
+`Fast pointer = node.next.next;` 
+at each iteration check if any of the pointer equals to `null`
+When fast pointer is null slow pointer will be at the middle node just print node.data to get the result.  
+ 
+
+Print all the permutations of give string. 
+There are two approaches for this either 
+we can use `permute` library or 
+we can code using loops in `O(n^2)`. 
+ 
+
+Third last node of LinkedList, 
+above mentioned two pointer approach will be used here as well. 
+
+Difference between `call by value` and `call by reference`. 
+In call by value, we pass the copy of variable in the function whereas 
+in call by reference we pass the actual variable into the function. 
+How we do that? We pass the memory address of that variable to the function. 
+These concepts are used with pointers in C/C++. 
+
+Difference between `==` and `===` in JavaScript. 
+Both are used for comparison 
+double equal to is a content comparator whereas 
+triple equals compares both content and data types of LHS & RHS. 
+
+Difference between Breadth-first search & Depth first search. 
+
+
+****************************************************************************