Interview questions for Python developer for coding specialist

Python Developers are coding specialists who develop back-end components for advanced web applications. They write server-side logic and integrate front-end technologies using the Python application.
When interviewing Python Developer, look for candidates with practical experience with front-end development and in-depth knowledge of application integration.

1. What sets Python apart from other high-level scripting languages?

Assess the candidate’s knowledge of Python versus other high-level languages.

2. What type of language is python? Programming or scripting?

Python is capable of scripting, but in general sense, it is considered as a general-purpose programming language. To know more about Scripting, you can refer to the Python Scripting Tutorial.

3. What other frameworks are useful for back-end development?

Reveals the candidate’s experience with back-end technologies.

4. How is Python an interpreted language?

An interpreted language is any programming language which is not in machine level code before runtime. Therefore, Python is an interpreted language.

5. What was the most difficult project you have worked on and why?

Reveals previous work experience and highlights the extent of the candidate’s coding abilities.

6. What is pep 8?

PEP stands for Python Enhancement Proposal. It is a set of rules that specify how to format Python code for maximum readability.

7. What is PYTHONPATH?

It is an environment variable which is used when a module is imported. Whenever a module is imported, PYTHONPATH is also looked up to check for the presence of the imported modules in various directories. The interpreter uses it to determine which module to load.

8. What ratio did you choose to divide your dataset into training and testing sets?

A classifier needs us to divide a dataset into training and testing sets. The ratio is very important because it can affect the accuracy of the model. If we have few training data, the parameter estimates will have greater variance. And if we have a few test data, the performance statistic will have greater variance. Depending on the purpose and the size of the dataset, we usually split the dataset into 60% to 80% for training, and 40% to 20% for testing.

9. What are python modules? Name some commonly used built-in modules in Python?

Python modules are files containing Python code. This code can either be functions classes or variables. A Python module is a .py file containing executable code.
1. Memory management in python is managed by Python private heap space. All Python objects and data structures are located in a private heap. The programmer does not have access to this private heap. The python interpreter takes care of this instead.
2. The allocation of heap space for Python objects is done by Python’s memory manager. The core API gives access to some tools for the programmer to code.
3. Python also has an inbuilt garbage collector, which recycles all the unused memory and so that it can be made available to the heap space.

10. What challenges did you face in your best Python projects?

Which algorithm to use was a challenge to figure out. Since the algorithm you use can affect your model’s accuracy, it is always a task to decide what algorithms and concepts to use together. Also, managing the changes to the code was tough, and that taught me the importance of version control. It was also important to make my code readable and easily modifiable.

11. What is namespace in Python?

A namespace is a naming system used to make sure that names are unique to avoid naming conflicts.

12. What do you know about palindromes? Can you implement one in Python?

A palindrome is a phrase, a word, or a sequence that reads the same forward and backward. One such example will be pip! An example of such a phrase will be ‘nurses run’.

13. What is PYTHONPATH?

It is an environment variable which is used when a module is imported. Whenever a module is imported, PYTHONPATH is also looked up to check for the presence of the imported modules in various directories. The interpreter uses it to determine which module to load.

14. What is the iterator protocol?

The iterator protocol for Python declares that we must make use of two functions to build an iterator- iter() and next().
1. iter()- To create an iterator
2. next()- To iterate to the next element
1. >>> a=iter([2,4,6,8,10])
2. >>> next(a)

15. What are python modules? Name some commonly used built-in modules in Python?

Python modules are files containing Python code. This code can either be functions classes or variables. A Python module is a .py file containing executable code.

16. When you exit Python, is all memory deallocated?

Exiting Python deallocates everything except:
• modules with circular references
• Objects referenced from global namespaces
• Parts of memory reserved by the C library

17. What is the Dogpile effect?

In case the cache expires, what happens when a client hits a website with multiple requests is what we call the dogpile effect. To avoid this, we can use a semaphore lock. When the value expires, the first process acquires the lock and then starts to generate the new value.

18. Is indentation required in python?

Indentation is necessary for Python. It specifies a block of code. All code within loops, classes, functions, etc is specified within an indented block. It is usually done using four space characters. If your code is not indented necessarily, it will not execute accurately and will throw errors as well.

19. What is pickling and unpickling?

Pickle module accepts any Python object and converts it into a string representation and dumps it into a file by using dump function, this process is called pickling. While the process of retrieving original Python objects from the stored string representation is called unpickling.

20. What are the generators in python?

Functions that return an iterable set of items are called generators.