Python quizzes, interview questions and answers

Some of the answers are wrong, or reveal only a shallow understanding of Python. For example:

> 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.

The first sentence is wrong. File objects, for example, cannot be pickled. Also, in Python3, which makes a stronger distinction between a 'string' and 'bytes', a pickle returns bytes, not a string. Also, the pickle module can pickle to/from bytes without touching a file.

For another example:

> How will you compare two lists?

> cmp(list1, list2) − Compares elements of both lists.

The answer is "list1 == list2", for most uses of 'compare'. The 'cmp' function is no longer part of Python, and its use was a bit tricky.

For a third:

> What are the rules for local and global variables in Python?

> If a variable is defined outside function then it is implicitly global. If variable is assigned new value inside the function means it is local.

This is not correct. Consider:

    class Spam:
        x = 5

The variable x is neither defined in a function nor is a global variable.

Looking through the answers, I would discourage people from using this site. It is better to read the Python documentation and FAQ.