DEV Community: Amina Ali

Python for everyone: Mastering Python The Right Way

Amina Ali — Mon, 28 Feb 2022 18:52:11 +0000

One of the most asked questions you get asked as a developer or maybe even u asked on your journey to being a developer is “ what is the right way of mastering python or any other programming language ?” and my answer is simple: understand how to learn , why do i say this ?

I believe that the first step in learning any programming language is making sure that you understand how to learn. Learning how to learn is arguably the most critical skill involved in computer programming.
Why is knowing how to learn so important? The answer is simple: as languages evolve, libraries are created, and tools are upgraded. Knowing how to learn will be essential to keeping up with these changes and becoming a successful programmer.
Various learning technique are reading python programming books watch the youtube link below to search for a few of which i suggest you get your hands on https://www.youtube.com/watch?v=iKjlIud4So8

Other learning technique are watching youtube tutorials or any other tutorials on the how to learn python here are few youtube channel i believed it helped me and will help you on your beginner journey as a python developer
Freecodecamp.org, The odinproject.com , Codeacademy.com , khanacademy.com, developer .mozilla.org, W3schools.com , Studywebdevelopment.com ,Coursera.org , Teamtreehouse.com.
You can also enroll in the coding school either physical or online to get taught by my mentor . all above technique are the best way i can say are the best way to learn

Check out this previous article https://dev.to/aminaali/introduction-to-modern-python-2jch
where I explained how to install and set up your python , introduction to python as well as some exercise to get you started . Check this other article to learn Data structure in python https://dev.to/aminaali/introduction-to-data-structures-and-algorithms-with-python-1686

Tips that can help you master what you learn

1.Code everyday
Believe it or not, coding everyday even for a min of 1hr as a start and working your way to 10 hr or more hours a day as a successful developer does can really boost your skills in mastering the language . As we know Consistency is very important when you are learning a new language thus make a commitment yourself to to code every day , Committing to coding everyday will really help develop that muscle memory. It may be hard to believe this but try putting into practice what you learn . As the saying goes practice makes perfect .

2.Surround yourself with those who code
As you learn how to code in python , learn to work in a team too , it actually works best when you work together. It is extremely important when you are learning to code in Python that you surround yourself with other people who are learning as well. This will allow you to share the tips and tricks you learn along the way. You can also join the python developer whatsapp group , slack community or any other social media developer community to learn and also join python developer meetup
3. Teach
It is said that the best way to learn something is to teach it. This is true when you are learning Python. There are many ways to do this : writing a technical article of the concept in python you learned and sharing it online .Recording videos in which you explain something you learned and posting it online on youtube or other social media platform . . Each of these strategies will solidify your understanding as well as expose any gaps in your understanding.
4.Build projects
For beginners, there are many small exercises that will really help you become confident with Python . Once you have a solid grasp on basic data structures (strings, lists, dictionaries, sets) , object oriented programming in python , it's time you start building simple app in python .The journey of building is truly what will teach you the most , error may come up along the way as you build your app but Don’t let bugs frustrate you. Instead, embrace these moments with pride, the bugs and errors you solve will teach you a lot.
5.Contribute to open source communities
In the open-source model, software source code is available publicly, and anyone can collaborate. There are many Python libraries that are open-source projects and take contributions. Additionally, many companies publish open-source projects. This means you can work with code written and produced by the engineers working in these companies. Contributing to open source projects is an extremely valuable way to learn through experience. Let's say you clone an open source project on your local machine, fix some bugs or even add some functionality and push your request . the project manager will see your change and even pull the request and Boom you're getting noticed .

Introduction to Data Structures and Algorithms With Python

Amina Ali — Sun, 20 Feb 2022 17:37:31 +0000

Data structure

Data structure is a specialized means of organizing and storing data in computers in such a way that we can perform operations on the stored data more efficiently

Algorithm

is a step-by-step procedure for solving a problem in a finite amount of time with finite amount of effort(resources).
What is an efficient algorithm :One whose function's values are small, or grow slowly compared to a growth in the size of the input.

Types of Data structure

Python has implicit support for Data Structures which enable you to store and access data. These structures are called list , Dictionary , sets and tuples
Python also allows its users to create their own Data Structures enabling them to have full control over their functionality . The most prominent Data Structures are
Stack,Queue, Tree, Linked List , graph **and **hash tables .

1. List

To represent a sequence of items indexed by their integer position, one data structure you can use is a list. Lists contain zero or more elements and can contain elements of different types. List is a mutable ordered sequence of element mutable meaning that you can add, delete, or change elements in a flexible manner
Access list items:
List elements are accessed by the assigned index.Starting index of the list is 0 and the ending index is n-1 where n is the number of elements.
students[0] _gets the first element in a list
_students[0] = ‘Amina' changes a list item by offset.
students[0:2] _slices to extract items by offset. This example returns the first 2 elements of students.
Add list items:
_append() _adds an item to the end of a list.
_extend() or += merges one list into another.
insert() adds an item before any offset.
Remove list items:
remove() removes an item value from a list.
pop() removes the last (or specified) element while also returning the value.
del removes an item by its position in the list. del is a Python statement, not a list method.
join() returns a string of combined list items. The argument for join() is a string or any iterable sequence of strings.
_len() _returns the number of items/length in the list.
_count() _returns the number of occurrences of a specified value.

#defining  a list 
students = ['sam', 'pam', 'rocky', 'austin', 'steve', 'banner']
#acessing element in a list 
print(students[0])
print(students[-3])
print(students[1:3])

#adding element in a list 
students.append("amina")
print(students)

#deleting element in a list
students.pop(0)
print(students)

#printing the len of the list 
print(len(students))

#join string in a list
name = "-".join(["Jack", "O", "Lantern"])
print(name)

output:
sam
austin
['pam', 'rocky']
['sam', 'pam', 'rocky', 'austin', 'steve', 'banner', 'amina']
['pam', 'rocky', 'austin', 'steve', 'banner', 'amina']
6
Jack-O-Lantern

2 Dictionaries

Instead of using an offset, dictionaries use keys to associate with each value. This means that order is not tracked and should not matter if you plan to use a dictionary. Dictionary keys are immutable and unique, however, dictionaries are mutable; the key-value elements can be added, deleted, or changed
Create dictionaries using {}. Typecast using dict()

Access value in dictionary
book[‘key’] gets an item by its key

*Updating value in a dictionary *
book['key'] = ‘value' _uses a key to add (or change if it already exists) a value.
_update() merges the keys and values of one dictionary into another.

*Removing value in a dictionary *
del deletes an item by the provided key. del is a Python statement, not a dictionary method.
keys() returns all the dictionary keys. values() returns all the values in the dictionary. items() returns all the dictionary key-value pairs.

# dictionaries help us store complicated data, which is not single valued like a number or a string
book = {
    'title': "How to be awesome",
    'author': "john doe",
    'isbn': "1234-23-15-12-3",
    'date_published': "23-21-2010",
    'year': 2010}
# access value in a dict
book_title = book['title']
print(book_title)
# update value in a dict
book['title'] = "2020 what went wrong"
print(book["title"])
# get all the keys in this dictionary
keys = book.keys()
print(keys)

#deleting item from dictionary 
del book['isbn']
print (book)

#adding item to dictonary 
book['page']=450
print(book)

#Checking if a Key exists
if "year" in book:
  print("Yes, the keyword exists in the dictionary")
else:
  print('No, the keyword does not exist in the dictionary')

output
How to be awesome
2020 what went wrong
dict_keys(['title', 'author', 'isbn', 'date_published', 'year'])
{'title': '2020 what went wrong', 'author': 'john doe', 'date_published': '23-21-2010', 'year': 2010}
{'title': '2020 what went wrong', 'author': 'john doe', 'date_published': '23-21-2010', 'year': 2010, 'page': 450}
Yes, the keyword exists in the dictionary

3 Tuples

Tuples are also a sequenced data structure, just like lists. However, tuples are immutable; you cannot add, delete, or change items after a tuple is created. Tuples differ from lists by having many fewer functions because they can’t be modified after being defined. Tuples contain zero or more elements and can contain elements of different, immutable types
Create tuples using () or a comma-separated list of elements with no surrounding brackets or braces. Typecast using tuple().

Accessing element in a tuples
Accessing items in a tuple is similar to a list, we can access elements in a tuple using indexes. We can specify the index value and it will return the item stored at that particular index value.

Concatenating two tuples

vector = (4, 5, 9)
#acessing element in  a tuple
print("x-coordinate:", vector[0])
print("y-coordinate:", vector[1])
print("z-coordinate:", vector[2])

location = 108.7774, 92.5556
latitude, longtitude = location
print("The coordinates are {} x {}".format(latitude, longtitude))

output:
x-coordinate: 4
y-coordinate: 5
z-coordinate: 9
The coordinates are 108.7774 x 92.5556

4.Sets

A set is like a dictionary with only the keys, not the values. This means that sets are unique and not sequential. Sets are also mutable. Sets contain zero or more elements and can contain elements of different, immutable types .Create sets using set(). Typecast using set().
Operation that can be done in a list
add() adds an item to the set if it doesn’t already exist
remove() removes specified items from the set
intersect() returns an intersection of two sets
union() returns a union of two sets

set ={1,2,5, "amina"}
print(set)
#acessing item in a set
for x in set:
  print(x)
#add item in a set
set.add("sandra")
print(set)

#deleting element in set 
set.remove("amina")
print(set)

output:
{1, 2, 5, 'amina'}
1
2
5
amina
{1, 2, 5, 'sandra', 'amina'}
{1, 2, 5, 'sandra'}

5. Stack

Stack are linear Data Structures which are based on the principle of Last-In-First-Out (LIFO) where data which is entered last will be the first to be accessed. It is built using the array structure and has operations namely, pushing (adding) elements, popping (deleting) elements and accessing elements only from one point in the stack called the TOP. This TOP is the pointer to the current position of the stack.example :5 is added in to the stack ontop of 4 and while removing you have to start with the top most element which 5 is removed first followed by 4 thus the term Last-In-First-Out .

Operation done in stack
empty()– Returns whether the stack is empty.
size() – Returns the size of the stack.
top()– Returns a reference to the topmost element of the stack.
push()– Inserts the element ‘a’ at the top of the stack.
pop() – Deletes the topmost element of the stack.

# implementing stack using List :
myStack = []
#adding item to the stack 
myStack.append(10)
myStack.append(100)
myStack.append(1000)
myStack.append(10000)
print("Initial stack is:",myStack)
#removing utem form the list
print(myStack.pop())
print(myStack.pop())
print(myStack.pop())
print("After Removing elements:",myStack)

output:
Initial stack is: [10, 100, 1000, 10000]
10000
1000
100
After Removing elements: [10]

6. Queues

A queue is also a linear data structure which is based on the principle of First-In-First-Out (FIFO) where the data entered first will be accessed first. It is built using the array structure and has operations which can be performed from both ends of the Queue, that is, head-tail or front-back. Operations such as adding and deleting elements are called En-Queue and Dequeue and accessing the elements can be performed.

Operation performed in queues
enqueue(): Adds an element to the back of queue Q..
dequeue(): Removes and returns the first element from queue Q. Error occurs if empty.
empty(): Returns True if no elements found in queue Q, else returns False
size(): Returns the number of elements in queue Q.

# implementing Queue using List :
queue=[]
queue.append(10)
queue.append(100)
queue.append(1000)
queue.append(10000)
print("Initial Queue is:",queue)
print(queue.pop(0))
print(queue.pop(0))
print(queue.pop(0))
print("After Removing elements:",queue)

output
Initial Queue is: [10, 100, 1000, 10000]
10
100
1000
After Removing elements: [10000]

7.Linked list

A linked list is a linear data structure, in which the elements are not stored at contiguous memory locations. The elements in a linked list are linked using pointers.

Operation performed in linked list
Traversal: To traverse all the nodes one after another.
Insertion: To add a node at the given position.
Deletion: To delete a node.
Searching: To search an element(s) by value.

# A single node of a singly linked list
class Node:
  # constructor
  def __init__(self, data = None, next=None): 
    self.data = data
    self.next = next
# A Linked List class with a single head node
class LinkedList:
  def __init__(self):  
    self.head = None 
  # insertion method for the linked list
  def insert(self, data):
    newNode = Node(data)
    if(self.head):
      current = self.head
      while(current.next):
        current = current.next
      current.next = newNode
    else:
      self.head = newNode
  # print method for the linked list
  def printLL(self):
    current = self.head
    while(current):
      print(current.data)
      current = current.next
# Singly Linked List with insertion and print methods
LL = LinkedList()
LL.insert("Lux ")
LL.insert("Tech")
LL.insert("Academy")
LL.printLL()

output:
Lux 
Tech
Academy

introduction to modern python

Amina Ali — Sun, 13 Feb 2022 17:40:29 +0000

What is python ?

**
Python is an interpreted, general, high-level programming language invented by Guido van Rossum and released in 1991.

Installing and setting up python environment

**
Python installation steps

Visit https://www.python.org/downloads/ 2.Select your Operating system(Windows,Linux/UNIX,MacOS,Other
Select the release or version, click on it to download. 4.Double click on the file to execute and install. For window mark "add to system paths" An alternative way to install python on Linux is to run sudo apt install python3 or sudo apt install python on the terminal.
For more check on the python documentation for more documentations.

Check installed python

Open Terminal on Linux or cmd on windows ** Run the python --version command to check if you **installed the correct version. if python is installed, the output will be similar to as below:

Lets run some few code in python

*1.Print() function in python *
print() in python is a useful built
in function that we can use to display input value as text in the output.

*2.Variable in python *
Variables are used to store information to be referenced and manipulated in a computer program.
Creating a new variable in python is very simple, let's create one together, here in this example below the variable name is month, the equal sign is the assignment operator and the value of the variable is 12

*3. Data Type in Python *
Integers, Floats, Booleans, Strings, Lists, Tuples, Sets, Dictionaries
*Integer * - these are whole numbers
*Floats *- these are Numbers with a decimal point, such as 3.14, are called floating-point numbers (or floats).

Bool - Bool is another data type that is commonly used in Python. Bool is short for Boolean which can have a value of either True or False. Boolean algebra is the branch of algebra in which the values of the variables are the truth values true or false. Boolean algebra uses the framework on which all electronic devices are built and exists fundamentally in every line of code inside a computer. In python we can easily assign boolean values like this:

Strings - Python has another datatype in its toolkit called as Strings, as the name suggests this data type deals with characters words and text. String is an immutable order of sequences of characters (eg, Letters, numbers, spaces and symbols. We will be explaining what immutable order means later on.You can create a string by using quotes as seen here, you can use either single / double quotes they both work equally well but there are some cases where you might prefer one over the other which we will be discussing below.

Lists - A list is one of the most common and basic data structures in Python. It is a mutable ordered sequence of elements.The code below defines a variable students which contains a list of strings. Each element in the list is a string that signifies the name of a student.

Dictionaries -dictionaries help us store complicated data, which is not single valued like a number or a string

What is python used for ?

Python is the most popular programming language and is used in
1.Machine learning
2.Software development
3.Software testing prototyping
4.Data science
5.Automation and scripting

Advantage of python

It has a simple syntax that mimics natural language, so it’s easier to read and understand. This makes it quicker to build projects, and faster to improve on them.
It’s versatile. Python can be used for many different tasks, from web development to machine learning.
It’s beginner friendly, making it popular for entry-level coders.
It’s open source, which means it’s free to use and distribute, even for commercial purposes.
Python’s archive of modules and libraries—bundles of code that third-party users have created to expand Python’s capabilities—is vast and growing.
Python has a large and active community that contributes to Python’s pool of modules and libraries, and acts as a helpful resource for other programmers. The vast support community means that if coders run into a stumbling block, finding a solution is relatively easy; somebody is bound to have run into the same problem before.