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 experiencing performance bottlenecks in a Python program due to slow file I/O operations. How would you optimize the file reading and writing processes to improve performance?
- a. Use buffered I/O
- b. Upgrade the CPU
- c. Increase the file size
- d. Convert files to binary format
To optimize file reading and writing processes in Python, you should use buffered I/O. This involves reading/writing data in larger chunks, reducing the number of I/O operations and improving performance. Upgrading the CPU may not directly address I/O bottlenecks. Increasing file size and converting files to binary format may not be appropriate solutions for all scenarios and can introduce other issues.
You are debugging a failing test in pytest and need to inspect the values of variables at the point of failure. Which pytest option would you use to achieve this?
- Employ the --capture option
- Enable pytest logging with the --log-level option
- Use the --pdb option
- Utilize the --verbose option
To inspect variable values at the point of failure during debugging in pytest, you can use the --pdb option. This option invokes the Python Debugger (pdb) when a test fails, allowing you to interactively explore variables and the execution context.
You are designing a framework and want to ensure that all classes following a certain API have required methods implemented. How would you use metaclasses to achieve this?
- Metaclasses can automatically inject the required methods into all classes using the API.
- Metaclasses can be used to define a base class with the required methods, and then, for each class, you create a metaclass that checks if these methods are implemented.
- Metaclasses can be used to dynamically create subclasses with the required methods, enforcing the API.
- Metaclasses cannot be used for this purpose.
Metaclasses provide a way to define behaviors for classes. In this scenario, you can define a metaclass that checks if the required methods are implemented when a class is created, ensuring adherence to the API.
You are designing a RESTful API for an e-commerce platform. How would you structure the API endpoints to handle CRUD operations for products?
- a) /api/products/create, /api/products/read, /api/products/update, /api/products/delete
- b) /api/createProduct, /api/readProduct, /api/updateProduct, /api/deleteProduct
- c) /api/products POST, GET, PUT, DELETE
- d) /api/products, POST, GET, PUT, DELETE
In a RESTful API, CRUD operations are typically represented by HTTP methods. Option (c) follows REST conventions with POST, GET, PUT, and DELETE HTTP methods for creating, reading, updating, and deleting products.
You are designing an algorithm to match the opening and closing parentheses in an expression. Which data structure would be suitable for this purpose?
- Array
- Linked List
- Queue
- Stack
A stack is a suitable data structure for matching opening and closing parentheses in an expression. As you encounter opening parentheses, you push them onto the stack, and when you encounter a closing parenthesis, you pop from the stack, ensuring that they match. This approach helps maintain the order of parentheses and is well-suited for this purpose.