You are given a task to analyze the correlation between different numerical features in a dataset. Which Pandas method would you use to quickly observe the pairwise correlation of columns?
- .corr()
- .describe()
- .mean()
- .plot()
To quickly observe the pairwise correlation of columns in a Pandas DataFrame, you would use the .corr() method. It calculates the correlation coefficient between all numerical columns, providing valuable insights into their relationships.
You are implementing a caching mechanism. You need a data structure that removes the least recently added item when the size limit is reached. Which built-in Python data structure would you use?
- List
- OrderedDict
- Queue
- Set
An OrderedDict (Ordered Dictionary) is a built-in Python data structure that maintains the order of elements based on their insertion time. It can be used to implement a caching mechanism where the least recently added item can be removed when the size limit is reached.
You are required to build a Python generator that produces a sequence of Fibonacci numbers. How would you implement the generator to yield the Fibonacci sequence efficiently?
- Create a list of all Fibonacci numbers and return it as a generator.
- Implement the generator using a recursive approach to calculate Fibonacci numbers.
- Use a loop to generate Fibonacci numbers and yield them one by one.
- Use a stack data structure to generate Fibonacci numbers efficiently.
To generate Fibonacci numbers efficiently, you should use a loop and yield each Fibonacci number one by one. The recursive approach (Option 1) is inefficient due to repeated calculations.
You are required to create a Python module that should expose only specific functions when imported. How would you hide the internal implementation details and expose only the necessary functions?
- a) Use the __all__ attribute
- b) Define functions inside a class
- c) Use double underscores before function names
- d) Create a separate module for each function
To expose only specific functions when importing a Python module, you can define the __all__ attribute at the module level. This attribute is a list of function names that should be considered part of the module's public API, hiding the rest of the implementation details.
You are required to implement a custom iterator that needs to maintain its internal state between successive calls. Which method should you implement in your class to achieve this?
- __init__()
- __iter__()
- __next__()
- __str__()
To create a custom iterator that maintains internal state between successive calls, you should implement the __next__() method in your class. This method defines the logic for generating the next value in the iteration and should raise StopIteration when there are no more items to iterate over.
You are developing a Python program and need to debug a function in a module. Which Python tool would you use to step through the code and inspect the values of variables?
- a) print statements
- b) PyCharm
- c) pdb (Python Debugger)
- d) Python Profiler
To step through code, inspect variables, and debug Python programs, you would use the pdb module, which stands for Python Debugger. It allows you to set breakpoints, step into functions, and examine the state of your program during execution.
You are developing a RESTful API and need to ensure that sensitive user data is secure during transit. Which approach would you use to secure data transmission?
- a) Encoding data as plain text
- b) Using HTTPS (SSL/TLS)
- c) Encrypting data with a custom algorithm
- d) Adding authentication tokens to requests
The most secure approach for securing data in transit in a RESTful API is to use HTTPS (SSL/TLS). It encrypts the data between the client and server, providing confidentiality and integrity.
You are developing a system where you have multiple classes, and you want to ensure that a particular set of methods is available in all these classes. How would you ensure this?
- Inherit a base class with the common methods
- Use composition and create a separate class for the common methods
- Use global functions for the common methods
- Use interfaces to define the required methods
In JavaScript, you can't directly inherit from classes, but you can use interfaces to ensure a set of methods is available in implementing classes. Interfaces define method signatures that must be implemented by the classes that use them.
You are developing a system where you have multiple classes, and you want to ensure that a particular set of methods is available in all these classes. How would you ensure this?
- Use Composition
- Use Encapsulation
- Use Inheritance
- Use Polymorphism
To ensure that a particular set of methods is available in multiple classes, you would use Inheritance. Inheritance allows a class to inherit properties and methods from another class, making it possible to create a base class with common methods that are shared by multiple derived classes.
You are developing a test suite using the unittest framework and need to share the same setup code across multiple test cases. Which method would you use?
- Create a base test class with a setUp method
- Define setup code within each test case
- Use the @classmethod decorator with a shared setup method
- Use the @staticmethod decorator with a shared setup method
In the unittest framework, you can create a base test class with a setUp method to share common setup code across multiple test cases. This ensures that the setup code is executed before each test case in the suite.