Python for
Automation

Strings in python are surrounded by either single or double quotation marks. Let's look at string formatting and some string methods

# String Formatting
name = 'Brad'
age = 37

# Concatenate
print('Hello, my name is ' + name + ' and I am ' + str(age))

# Arguments by position
print('My name is {name} and I am {age}'.format(name=name, age=age))

# F-Strings (Only available in python 3.6 and after)
print(f'Hello, my name is {name} and I am {age}')

# String Methods

# Capitalize
s = 'hello world'
print(s.capitalize())

# Make all uppercase
s = 'hello world'
print(s.upper())

# Make all lowercase
s = 'hello world'
print(s.lower())

# Swap case
s = 'hello woRld'
print(s.swapcase())

# Get length
s = 'hello woRld'
print(len(s))

# Replace
s = ' hello world'
print(s.replace('world', 'everone'))

# Count how many 'H' in the variable or string
sub = 'h'
print(s.count(sub))

# Starts with will return true or false if the variable is starting with the provided name
s = 'hello woRld'
print(s.startswith('hello'))

# Ends with will do the opposite of starts with
s = 'hello woRld'
print(s.endswith('woRld'))

# Split into a list will convert it into a list which is an arry
s = 'hello woRld'
print(s.split())

# Find position
print(s.find('d'))

# Is all alphanumeric
print(s.isalnum())

# Is all alphabetic
print(s.isalpha())

# Is all numeric
print(s.isalnum())

A List is a collection which is ordered and changeable. Allows duplicate numbers.

#Create list
numbers = [1, 2, 3, 4, 5]
fruits = ['Apples', 'Oranges', 'Pears', 'Banana']

#Use a constructor
number2 = list((1, 2, 3, 4, 5))

print(numbers, number2)
print(fruits[0])

# Get length
print(len(fruits))

# Append to list
fruits.append('Mangos')
print(fruits)


# Extend list
fruits.extend(["fig", "grape"])

# Remove from list
fruits.remove('Banana')
print(fruits)

# Insert into position
fruits.insert(0, 'Strawberries')
print(fruits)

# Change value
fruits[0] = 'Blueberries'

# Remove with pop
fruits.pop(2)
print(fruits)

# Reverse the list
fruits.reverse()
print(fruits)

# Sort list (Alphabetically sorting)
fruits.sort()
print(fruits)

# Sorting reverse
fruits.sort(reverse=True)
print(fruits)


print(type(number2))

A Tuple is a collection which is ordered and unchangeable. Allows duplicate members. A Set is a collection which is unordered and unindexed. No duplicate members.

# Create tuple
fruits = ('Apples', 'Oranges', 'Grapes')
fruits2 = tuple(('Apples', 'Oranges', 'Grapes'))

print(fruits, fruits2)

# Single value needs trailing comma
fruits1 = ('Apples',)
print(fruits1, type(fruits1))

# Get value
print(fruits[1])

# Can't change value
# fruits[0] = 'pears'

# Delete tuple
# del fruits
print(fruits)

# Get lenth
print(len(fruits))


# A Set is a collection which is unordered and unindexed. No duplicate members.

# Create set ( it is created with curly braces)
fruits_set = {'Apples', 'Bananas', 'Mangos'}

# Check if in set
print('Apples' in fruits_set)

# Add to set
fruits_set.add('Grape')
print(fruits_set)

# No duplicate members (If the value already exists then it won't add it again or one more time)
fruits_set.add('Bananas')
print(fruits_set)

# Remove from set
fruits_set.remove('Grape')
print(fruits_set)

# Clearing set
fruits_set.clear()
print(fruits_set)

# Deleting set
del fruits_set
print(fruits_set)

A Dictionary is a collection which is unordered, changeable and indexed. No duplicate members.

# Create dict
person = {
    'first_name' : 'John',
    'last_name' : 'Doe',
    'age' : 30
}

print(person, type(person))

# User constructor
person2 = dict(first_name='Muhammad',last_name='Asad',age=30)

print(person2, type(person2))

# Get the value
print(person2['first_name'], 'Getting the value')

# Another way to get value using get method
print(person.get('age'), 'getting value with another method')

# Add key value
person['profession'] = 'Worker'
print(person, 'Adding key and value to the dictionary')

# Get dict Keys
print(person.keys(), 'Geting the keys')

# Get dict Values
print(person.values(), 'Getting the values')

# Copy the dict
person = person2.copy()
print(person, 'Copying the dictionary')

# Remove item
del(person['last_name'])
print(person, 'Removing last_name with remove method')

# Another method to remove an item
person.pop('age')
print(person, 'Removing age with pop method')

# Clear the data
person.clear()
print(person, 'Clearing Data')

# Getting length
print(len(person), 'getting the length of the Dictionary')

# List of dict
people = [
    {'name': 'Martha', 'age': 31},
    {'name': 'Addie', 'age': 25}
]
print(people, 'list/Array of dictionary')

# Getting the value from the array of dictionarry
print(people[0]['name'],people[1]['name'], 'getting the values from the array of dictionary')

If/ Else conditions are used to decide to do something based on something being true or false

# Comparision Operators (==, !=, >, <, >=, <=) - Used to compare values

x = 7
y = 10

# Simple if

if x > y:
    print(f'{x} is greator then {y}', ': Simple if condition')

# If / Else
    
if x > y:
    print(f'{x} is greator then {y}', ': if else condition')
else:
    print(f'{x} is less then {y}', ': if else condition')

# elif or else / if
if x > y:
    print(f'{x} is greator then {y}', ': elif or else / if condition')
elif x == y:
    print(f'{x} is equal to {y}', ': elif or else / if condition')
else:
    print(f'{x} is less then {y}', ': elif or else / if condition')

# Nasted if
    if x > 2:
        if x <= 10:
          print(f'{x} is greater than 2 and less than or equal to {y}',': Nasted if condition')  


# Logical Operators (and, or, not) - Used to combile conditional statements

# And logical operator
if x > 2 and x <= 10:
    print(f'{x} is greater than 2 and less than or equal to {y}',': logical operator (And) condition')  

# Or logical operator
if x > 2 and x <= 10:
    print(f'{x} is greater than 2 and less than or equal to {y}',': logical operator (Or) condition')  

# Not logical operator
if not(x == y):
    print(f'{x} is not equal to {y}',': logical operator (Not) condition')  

# Membership Operators (not, not in) - Membership operators are used to test if a sequence is presented in an object
numbers = [1,2,3,4,5,6,7,8,9,10]

z = 7
a = 13
# in
if z in numbers:
    print(z in numbers, ': in condition')

# not in
if a not in numbers:
    print(a not in numbers, ': not in condition')


# Identity Operators (is, is not) - Compare the objects, not if they are equal, but if they are actually the same object, with the same memory location:
    b = 10
    c = 10

    # is
    if b is c:
        print(b is c, ': is condition')

    if x is not y:
        print(b is not c, ': is not condition')

A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string).

# Creating list
people = ['John', 'Paul', 'Sara', 'Susan']

# Simple for loop
for Person in people:
    print(f'Current Person: {Person}', ': Simple loop')

# Break
for Person in people:
    if Person == 'Sara':
        break
    print(f'Current Person: {Person}', ': Break in loop')

# Continue will skip the 'Sara'
for Person in people:
    if Person == 'Sara':
        continue
    print(f'Current Person: {Person}', ': Continue loop')

# Range
for i in range(len(people)):
    print(people[i])

# Custom ranges
for i in range(3, 11):
    print(f'Number: {i}')


# While loops execute a set of statements as long as a condition is true.
        
count = 0
while count <= 10:
    print(f'Count : {count}')
    count += 1

A function is a block of code which only runs when it is called. In Python, we do not use curly brackets, we use indentation with tabs or spaces

# Create function
def sayHello(name):
    print(f'Hello {name}')

sayHello('John deo')

# Creating funcion with the default value
def sayHello(name = 'Asad'):
    print(f'Hello {name}')

sayHello()

# Return values
def getSum(num1,num2):
    total = num1 + num2
    return total

print(getSum(1,2))
# Another way to print
num = getSum(6,7)
print(num)

# A lambda function is a small anonymous function
# A lambda function can take any number of arguments, but can only have one expression. Very similar to JS arrow functions
# 'getSumlambda' is a funtion name
# 'lambda num1, num2' is telling that if will accept the parameteres 
# ': num1 + num2' is thie main functionality
getSumlambda = lambda num1, num2 : num1 + num2
print(getSumlambda(10,2))

Examples of various built-in string functions

# isalpha(): Checks if all characters in a string are alphabetic (letters)
string_alpha = "abc"
print(string_alpha.isalpha())  # Output: True

# isdigit(): Checks if all characters in a string are digits
string_digit = "123"
print(string_digit.isdigit())  # Output: True

# isspace(): Checks if all characters in a string are whitespace characters (spaces, tabs, newline)
string_space = " \t\n"
print(string_space.isspace())  # Output: True

# islower(): Checks if all characters in a string are lowercase
string_lower = "abc"
print(string_lower.islower())  # Output: True

# isupper(): Checks if all characters in a string are uppercase
string_upper = "ABC"
print(string_upper.isupper())  # Output: True

# startswith(prefix): Checks if a string starts with the specified prefix
string_start = "Hello, world!"
print(string_start.startswith("Hello"))  # Output: True


# endswith(suffix): Checks if a string ends with the specified suffix
string_end = "Hello, world!"
print(string_end.endswith("world!"))  # Output: True

# split(): Splits a string into a list of substrings based on a delimiter
string_split = "Hello, world!"
print(string_split.split(", "))  # Output: ['Hello', 'world!']

# join(iterable): Concatenates elements of an iterable (like a list) into a single string, using the string as a delimiter
my_list = ["Hello", "world!"]
print(", ".join(my_list))  # Output: Hello, world!

A class is like a blueprint for creating objects. An object has properties and methods (functions) associated with it. Almost everything in Python is an object

# Create class
class User:
    # Constructor
    def __init__(self, name, email, age):
        self.name = name
        self.email = email
        self.age = age

    def greeting(self):
        return f'My name is {self.name} and I am {self.age} and my balance is {self.balance}'
    
    def has_birthday(self):
        self.age += 1


class Customer(User):
    # Constructor
    def __init__(self, name, email, age):
        self.name = name
        self.email = email
        self.age = age
        self.balance = 0

    def set_balance(self, balance):
        self.balance = balance

# Init customer object
janet = Customer('Janet Johnson', 'janet@yahoo.com', 25)

janet.set_balance(500)

# Init user object
brad = User('Brad Traversy', 'brad@gmail.com', 37)

brad.has_birthday()
print(brad.greeting())

It is a special method within a class that gets automatically called when an object or instance of the class is created.

class faculty:
    def putdata(self):
        self.id=int((input("Enter Faculty ID")))
        self.name=input("Enter Name")
        self.salary=float(input("Enter Salary"))
    def display(self):
        print(f'Faculty ID : {self.id}')
        print(f'Faculty Name :{self.name}')
        print(f'Faculty Salary : {self.salary}')

a = faculty()
a.putdata()
a.display()



class faculty:
    def __init__(self):
        self.id=int((input("Enter Faculty ID")))
        self.name=input("Enter Name")
        self.salary=float(input("Enter Salary"))
    def display(self):
        print(f'Faculty ID : {self.id}')
        print(f'Faculty Name : {self.name}')
        print(f'Faculty Salary : {self.salary}')

a = faculty()
# Here we don't need to call init, it will run automatically when an object is called or created
a.display()



# Parameter passing

class MyClass:
    def __init__(self, x, y):
        self.x = x
        self.y = y

# Create an instance of MyClass
obj = MyClass(10, 20)

# Access the instance variables
print(obj.x)  # Output: 10
print(obj.y)  # Output: 20

A module is basically a file containing a set of functions to include in your application.

# A module is basically a file containing a set of functions to include in your application.
# There are core python modules, modules you can install using pip package manager (incuding Django) as well as custom modules

# Core Modules

# Importing date time module
import datetime
today = datetime.date.today()
print(today)

# Another way of importing directly date from the datetime
from datetime import date
today1 = date.today()
print(today1)

# Importing time
import time
timestamp = time.time()
print(timestamp)

# Pip Modules
from camelcase import CamelCase

c = CamelCase()
print(c.hump('hello there world'))


# Import Custom Module
import Validator
from Validator import validate_email

email = "test@test.com"
if validate_email(email):
    print('Email is valid')
else:
    print('Email is bad')

Test your skills with these real-world Python interview questions. Try to solve them yourself before viewing the solution.