Python Developer Interview Preparation Guide

☛ List Vs Tuple.
The major difference between a list and the tuple is that the list is mutable while tuple is not. A tuple is allowed to be hashed, for example, using it as a key for dictionaries.

The ternary operator is an alternative for the conditional statements. It combines of the true or false values with a statement that you need to test. The syntax would look like the one given below.

[onTrue] if [Condition] else [onFalse]

x, y = 35, 75
smaller = x if x < y else y
print(smaller)

The <yield> keyword can turn any function into a generator. It works like a standard return keyword. But it’ll always return a generator object. Also, a function can have multiple calls to the <yield> keyword.

See the example below.

def testgen(index):
weekdays = ['sun','mon','tue','wed','thu','fri','sat']
yield weekdays[index]
yield weekdays[index+1]

day = testgen(0)
print next(day), next(day)

#output: sun mon

PEP 8 is a coding convention, a set of recommendation, about how to write your Python code more readable.

There are mutable and Immutable types of Pythons built in types Mutable built-in types
☛ List
☛ Sets
☛ Dictionaries

Immutable built-in types
☛ Strings
☛ Tuples
☛ Numbers

A mechanism to select a range of items from sequence types like list, tuple, strings etc. is known as slicing.

To share global variables across modules within a single program, create a special module. Import the config module in all modules of your application. The module will be available as a global variable across modules.

It is a Floor Divisionoperator , which is used for dividing two operands with the result as quotient showing only digits before the decimal point. For instance, 10//5 = 2 and 10.0//5.0 = 2.0.

The common way for the flask script to work is

☛ Either it should be the import path for your application
☛ Or the path to a Python file

Dogpile effect is referred to the event when cache expires, and websites are hit by the multiple requests made by the client at the same time. This effect can be prevented by using semaphore lock. In this system when value expires, first process acquires the lock and starts generating new value.