Complete Python Developer in 2021 : Zero to Mastery :::

 

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Complete Python Developer in 2021 : Zero to Mastery :::

Python Community :

Join by clicking here: https://discord.gg/nVmbHYY

Trainers : Blog to stay up-to-date with whats new in Python

https://zerotomastery.io/blog/?tag=PM 

ACADEMY : ZTM  : https://zerotomastery.io/courses

Python Cheat Sheet : https://github.com/aneagoie/ztm-python-cheat-sheet

 

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Section 1: Introduction ::

1. Course Outline   

2. Join Our Online Classroom!

3. Exercise: Meet The Community 

Section 2: Python Introduction ::

4. What Is A Programming Language

5. Python Interpreter 

There are two types of translator "Interpreter" & "Compiler"

1. Interpreter :  An interpreter is a translator that translates you code line by by 

2. Compiler : Compiler is one that take the entire file of code , translates and then compiles it

We can download it from the python.org

The interpreter that you are downloading is a code that is written in "C" language and it it called the 

• CPYTHON .  -- Written in C language
• JYTHON -- Written in Java labguage 
• pypy -- Is written in python 
• IRON-PYTHON -- Which is written for the .NET framework

But when you are download from python.org the official language is CPYTHON 

We are downloading a machine that takes our python code we are going to write and it goes to the interpreter which we download using CPython . And this CPYTHON is going to create something called a byte . This byte code prints hello world 

The CPYTHON is going to create something called the byte code , byte code is closer to machine code it used the cpython vm machine - something that run the code and this runs on our machine 

so when we are downloading the cpython and cpythonvm 

6. How To Run Python Code

What are going to use in our learning

1. Terminal
2. Code Editiors (Sublime text / visual studio code) 
3. IDEs (Pycharm and Spider )
4. Jupyter Notesbooks

Instead of download this we ca n go to ........."    repl.it    "  -- Create an account here . It allows to save python files online. Or you can use glot.io

 

repl.it    /  glot.io

 Here you can write your programs online - This is an online interpreter.

or you can use

glot.io instead 

7. Note: Jumping To Developer Environment ::

8. Our First Python Program ::

We are using repl.it to write the program . This creates main.py . Any file which has the py extension is a python file .

print("") or print('')

name =  input("Enter Your name : " )

print(name)

print("Hellllloooooooo ' + name)

9. Latest Version Of Python ::

Dicusses that Repl updates the latest version of the python a little late , so you may not find the latest version of python .

10. Python 2 vs Python 3 ::

The difference between python 2 and python 3 . A programming language is contently updated . No programming language is complete . In 2008 , the founder and the community wanted to create python 3 . 

11. Why So Many Languages? ::

Python, Java and Javascript is more than enough for getting many jobs and this is mostly most of the people can learn. 3 languages 

Python is slower than languages like C++, C# or JAVA . You dont have to write python code for low level systems . 

Python may be slow but does one thing very well, developer productivity . You would use python in scenarios when you want to do machine learning , you want to build a webserver , may be you want to do data visualizations. Build script that processes thousands of excel files , in that case you are going to use python. 

12. Exercise: How Does Python Work? ::

Go to the community : https://discord.gg/nVmbHYY 

connect with a buddy and explain -- How python works ..nothing special in this lesson .

13. ZTM Python Cheat Sheet ::

The trainer has a blog where he updates new things about python if you want to update to date with python follow this link : https://zerotomastery.io/blog/?tag=PM 

16. Learning Python ::

For any programmer to master any language there are four key things that he needs to master , including python 

1. Terms of that language - words / definitions that you have to got to memories (Statements /variables / instantiation / 
2. Datatypes of the language (what sort of data can a program hold )
3. Actions (Such as store this data / retrieve this data and perform some action on it)
4. Best Practices : There are good ways of writing python code and there are bad ways, when we build our applications and programs .

17. Python Data Types ::

1. int 
2. float
3. bool for boolean
4. str - stands for string
5. list
6. tuple
7. set
8. dict

A datatype is a value in Python , we need to know how to manipulate a language , create / store / change , remove this data from the machine.

Class data types 

After the fundamental data type we also have something called classes. : So beyond the fundamental datatype as listed above we can create our own. So these will be custom types . I can create a datatype and I can name it anything I like

example : supercar 

Specialized Datatypes : These are not build into python but are special packages or modules that we can use it from libraries 

Another type is "None" datatype, an idea of 0 in math / or absents of value 

18. How To Succeed ::

In order to get the most out of the course, I encourage you to code along with me throughout the next sections. Watching videos may help, but nothing beats hands on practice and actually coding to develop your skills and make you comfortable with Python. Let's get started!

19. Numbers ::

print(4 + 6)

What is the type of 4 + 6

print(type(4 + 6))     / type command to ask what datatype is this ?

print(type(6 + 4))

print(type(6 * 2))

print(type(6 / 2))

print(type(6 - 2))

print(type(6 - 2))

A floating point number is a number with a decimal point .

print(type(0.44131)) -- answer is float

A float takes a lot more space in memory than an integer datatype 

To learn more on floating point numbers : https://docs.python.org/3/tutorial/floatingpoint.html

print ( 2 ** 2)  -- This mean 2 to the power of 2

print ( 2 // 4) -- This gives out the integer rounding the figure to an integer.

)

print( 5 % 4) -- What is the reminder of this division (modular operator)

20. Math Functions ::

round is an in build function 

round(2.1) -- the rounds the figure and give . This will not give out any result we need to include print command as below to see an output

print(round(3.1)) : returns a round up figure

print (abs(-23)) :  This return an absolute number which is a no negative number .

To learn more on Python - Math Function : Google : Python3 math functions

The programmer says many of them he has never ever used in his programming career. Some of them you will never use it in your career , the key is to know how to google them when you needs them

21. DEVELOPER FUNDAMENTALS : :

Tells you how to avoid the mistake that he did while he started as a programmer . Important think 

to know is that you cannot memories everything . Every programmer uses google .

1. Don't read the dictionary, there a thousand things that one cannot memorize , such as  the in build functions. There is a standard library for in-build functions, datatype that you will not use 99 percent of the times. and so on.

22. Operator Precedence ::

different operator has precedence over different ones 

for instance

20 + 3 * 4 = > this gets multiplied first and the gets added. the multiplication get the first preference.

20 - 3 * 4 = > same here multiplication first 

print ((20-3) + 2 ** 2) ==> Here the first preference will be 20-3 which is covered in parenthesis , then the next precedence will be 2 ** 2 and finally you have " + 2 " that gets added to the finally

Precedence 

1. ()
2. **
3. * /
4. + -

Exercise: Operator Precedence ::

Throughout the course, we will have many exercises to help you learn. Moving forward, these exercises will be attached to each video (if it has an exercise) which can be accessed in your Udemy video player under "resources". To get you comfortable using this feature, and the online Repl.it we are going to use, you can see the exercise for this lesson attached. Good luck and see you in the next video!

For more information: https://support.udemy.com/hc/en-us/articles/229603648-How-to-Access-And-Use-The-Course-Player

24. Optional: bin() and complex ::

There another set of datatype " complex " -- we won't be learning about this data type , for we will only be using this when you are doing really really complex math .  Complex number is equivalent to a real number. But this something that you don't need to worry 99% of the time.

The variable store the values for int , float as binary numbers in memory .

You can use : an action or a function you can use in python called bin - stands for binary. which gives the binary representation of that number such as integer 

print(bin(5))  // The binary number for 5 is 101 , in our example we get 0b101 the b indicated by python is to indicate it is a binary number .

if you want to covert a binary number to an integer

print(int('0b101' , 2) - 2 is the base number indicating that it is a binary number

25. Variables ::

Variables store information that can be used in our programs , lets say in a quiz you have score 190 

and you want to store it in a variable, you can name the variable anything .

iq = 190 

Variable are called "Snake-Case" - means it is all lower case and the is space they don't exist we use underscore 

1. Variable must start with a lower case or an underscore
2. Variables can be anything (letters / numbers / underscore )
3. Case Sensitive
4. Don't over write keywords -- mean we cannot do this print(print)  // because the print keyword is already defined in python programming for some function.

print = 190 

print(print) -- this wont work .

https://www.w3schools.com/python/    -- Looks for what are keywords .

The good practice of coding is to make variable names descriptive , so if a new developer comes and sees it . He is understands it easily .

iq = 190 

user_age = iq / 4 

print(user_age)

once again assign it to another variable 

iq = 190 

user_age = iq / 4 

a = user_age 

print(a)

Constants :: There is an idea of constants . And constants are things that never change in a program

#constant

PI = 3.14  -- The varibles in caps-lock is to indicate that it is a constant and it is not meant to change.

You can still over write like below

PI = 3.14

PI = 0  // This is overwriting the earlier value .

But as a good practice you wouldn't change the value of constants 

Variable starting with double underscore -- are called dunder (cross-verify name) . There are allowed to be touched .

NOte** : Do not create a variable starting with two underscore. You can do it indeed . But it is generally not a good practice . 

Naming a variable is one of the most important skill you have as a programmer . So many time when the programmer does not make the variable names descriptive and this makes it difficult for a new programmer to adopt understand the code easy. Make variable naming simple so that the code reads like English .

a, b, c =  1, 2 ,3   // This is another way to assign values to variables .

a, b, c = 1, 2 ,3

print(a)

print(b)

print(c)

print(a,b,c)

26. Expressions vs Statements ::

Expression in the below statement

iq = 150

user_age = 1q /5  -- The one marked in red is called "expression" , this produces the value 

" user_age = 1q /5 "  -- This is a statement - the entire line of code

27. Augmented Assignment Operator ::

some_value = 5

some_value = ( some_value + 2)

print(some_value)

using an Augmented assignment operator 

some_value += 2   // You will be doing the same thing as some_value = ( some_value + 2)

or 

some_value -= 2  // With the minus sign it with subtract 2 from the some_value

You cannot do a direct some_value -= 2 // the some_value must be assigned with some value to perform this operation. meaning to say it should have a defined value already