Python Developer

☛ 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.

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.

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

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.

Help() and dir() both functions are accessible from the Python interpreter and used for viewing a consolidated dump of built-in functions.

☛ Help() function: The help() function is used to display the documentation string and also facilitates you to see the help related to modules, keywords, attributes, etc.

☛ Dir() function: The dir() function is used to display the defined symbols.

☛ You can use PyChecker, which is a static analyzer. It identifies the bugs in Python project and also reveals the style and complexity related bugs.

☛ Another tool is Pylint, which checks whether the Python module satisfies the coding standard.

No, Python does not have a Switch statement, but you can write a Switch function and then use it.

There are two ways to copy objects in Python.

☛ copy.copy() function

☛ It makes a copy of the file from source to destination.

☛ It’ll return a shallow copy of the parameter.

☛ copy.deepcopy() function

☛ It also produces the copy of an object from the source to destination.

☛ It’ll return a deep copy of the parameter that you can pass to the function.

NumPy is a Python package for scientific computing which can deal with large data sizes. It includes a powerful N-dimensional array object and a set of advanced functions.

Also, the NumPy arrays are superior to the built-in lists. There are a no. of reasons for this.

☛ NumPy arrays are more compact than lists.

☛ Reading and writing items is faster with NumPy.

☛ Using NumPy is more convenient than to the standard list.

☛ NumPy arrays are more efficient as they augment the functionality of lists in Python.

It is a single expression anonymous function often used as inline function.

Python sequences can be index in positive and negative numbers. For positive index, 0 is the first index, 1 is the second index and so forth. For negative index, (-1) is the last index and (-2) is the second last index and so forth.

To generate random numbers in Python, you need to import command as

import random

random.random()

This returns a random floating point number in the range [0,1)