Ultimate Python Beginner's Guide.
Tags: python, beginners, firstcode
Published: 2022-02-15 02:15:44

# Everything you need to write your first python code.


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Looking at lines of code as a begginer can really scare one off into thinking that programing is hard. Truth is it's neither here or there. Programing is simply the process of converting High-level language, that is easily understood by a human, to a low-level language that a computer can execute. 



The good news is that Python is very easy to learn of most of the languages. Even a child can code in python. Apart from that, it has a lot of applications that you might find interesting. In this article, we will learn all the basic concepts of Python in a very simple way that will help you write your first code! 



###Advantages of Python
First of all you may want to know some advantages of Python:

1. It can work on differnt platforms, ie Wimdoss, Mac, Pi Linux ect.
2. It is object oriented
3. It has a lot of libraries
4. it has a wide range of application 
5. It is easy to use,



### Applications of Python

You can apply Python in areas like;

- Web Development

- AI and Machine Learning

- Game development

- Data Science

- Audiou and Visual applications

- Software Development



##Getting Started

You first need to set up a working environment for Python by following the steps below; 


1.Download and install Python from their [page](https://www.python.org/downloads/). Make sure you dowmload a version that is compatible with your OS.


2.Choose a code editor that you will work with and install it. I recommend using Visual Studio Code. You can download it [here](https://code.visualstudio.com/download).


3.Confirm whether your python is installed by typing the code below on your Command Prompt.

```
python --version
```


# Basics of Python


## Variables
Variables store information that can be used in one's program. In technical terms, the variable is a memory location assigned some value called a literal. For instance


```
Variable
a=5
b="Mathew"
```
In a=5      a is the varible ,5 is the literal while in b= "Mathew" b is the variable, Mathew is the literal





## Data Types


In the example above, there are two types of data used, that is an integer 5, which is a whole number and a string "Mathew".
In python we have several data types;

- Numbers

Integers:      Whole numbers   ` 1,3,5,20`

Float:         Numbers with decimals    `0.5, 45.6`

Complex :       Numbers with Imaginery parts  `2+ 5i`



- String

A string is an immutable collection of alphabets, characters or words usually denoted with either double or single quotation marks.

```
a= "python"
   Print(a)

OUTPUT
<python>
```



- Boolean

There are two boolean values, `True` and `False`. They are used to show the truth values of an expression in a code.
For example

```
a=10
b=5
  Print (b>a)

OUTPUT
>>> False
```


## Identifiyer

These are names assigned to a variable, class, function or module in python.
 NB. Identifiers are case sensitive.

```
Amount= 122
name= "Mwaviki"
```
Amount and name are identifiyers in the example above.



## Data Structures

These are specific ways in which data is organized in a block of code for effective operations. We have;

- Lists

A list in python is a group of items in `[]` separated by commas `,`. One can manitpulate the list by adding, removing or displaying specific items on the list using the commands shown below.

```
MyList= [1,2,3,4,5,6,7]

#Adding to the beginning of thelist
MyList[0]= 0                         OUTPUT 
                                      [0,1,2,3,4,5,6,7]
#Adding at the end
MyList.append(8)                      OUTPUT
                                      [1,2,3,4,5,6,7,8]
#Removing an item
MyList.remove(3)                       OUTPUT
                                      [1,2,4,5,6,7]

```



- Tuples

These are ordered 'immutable lists'. The contents are inside a `()` unlike in a list`[]`. With Tuples, one can only display items or delete the whole tuple.

```
MyTuple= (" Joy"," Grace","Jon"," Macy")
  Print (MyTuple[0:2])

#OUTPUT
("Joy","Grace")

```

- Sets

In Python a set is an unordered and unchangable collection of data. It can contain several items repreating themselves but will be omitted on printing the set. The items are enclosed in a `{}`

```
Myset= {20,20,35,50,45,80,50,95}
Print(Myset)

OUTPUT
{45,35,50,20,80,95}
```
NB: One can add or remove items from a set.

- Dictionary

Dictionaries are used to store data values which are paired with key values as shown below

```
MyDict={
           "Name":'James'
           "Age":34
           "Location":"Kenya"
           }
Print(MyDict["Age"])

OUTPUT
34
```



##Operator

- Arithmetic 

 Addition          `2+5 `______________` 7`          
 Substruction      `3-1`_______________ `2`
 Multiplication   `2*3`________________`6`
 Division         `10/5`_______________`2`
 Exponential     `2**3`________________`16`
 Floor division  `11//4`________________`2`
 Modulous        `11%5`_________________`1`



Assignment: Used to assign values to variables. They include:
 `=   5=5
  +=  x+=3_______________ x+3
 -=   x-=2_______________ x-2
 *=   x*=3_______________x*3
 /=   x/=1_______________x/1
 **=  x**=2______________ x**2
 //=  x//=4______________x//4
 %=`   x%=5_______________x%5
`&=`

Comparison: used to compare values
`<`_______________less than
`>`_______________greater than
`>=`______________greater or equal to
`<=`______________less than or equal to
`==`______________ same/equals ro
`!=`______________ not same/equal to

Bitwise:Used to write numbers in binary
`&________________and
|_________________OR
<<________________ a<<b shit bits of a to the left by b bits 
>>________________a>>b shift bits of a to the right by b units
~_________________NOT
^`_________________XOR
 

Identity: used to determine whether two objects are the same. 
`is, is not`

Logical: Used to combine conditional statements.
`and`
` or` 
` not`



##Functions

There are two types of functions in Python

- Built-in Functions
These are functions that aready exist in Python and have a specific purpose. There are more that 50 built in functions with the mostly used beind such as `Print`,`Input` etc.

```
Print("Hello World")

OUTPUT
Hello World

name= Input(" What is your name?: )
Print("Hi {name}")

OUTPUT
What is your age?: John(as an input) 
Hi John

```

- Calling a function 

Other functions in python are a block of code that runs only when called upon. To define a function one starts with `def` functionname followed with parameters in the function (parameters) as shown in the example below.
A function must return some results whenever is called upon. 

```
#The function has nothing to return
def MyFunc()
      return           

#Function is called  
MyFunc()  


def My2Func() 
  Print( "This is my function")
             

#Function is called
My2Func()

#OUTPUT
This is my function

```

## Comments
You can write comments in your code to help you organise your work in two ways. Comments would be skipped when the code is being run.

- Single line comment: putting a `#` before the line

`#this is my comments`

Block comment: Using three double quotation make at the start and end of code

```
"""a= "Commenting a block of code"
   Print(a)
"""
```



5. Loops and Condition statements

- For loops
This loop is used to iterate over a sequence once for an item according the the set statements. For instance

```
Numb= [1,5,10,]
For x in Numb
 Print (X)

OUTPUT
X:5
>>5

```

- While loop
This loop is will run the set statements until a certain condition is met.

```
n=0

While n <= 10
  Print (n)
n+=1

#OUTPUT
(0,1,2,3,4,5,6,7,8,9,10)

```

- If statement

```
a=15
b=10

If a>b
  Print ("a is greater than b")

```

- If...else

```
a= "Rain"

If a
 print ("Stay")
else:
  Print("Go")

```

- elif

If the prevision condition is not met then move to the next one.

```
a=15
b=10

if b>a
  print ("b is greater than a")
elif b<a
  print ("b is less than a")

```


####Conclusion

By now you shoul be able to write your first Python Code and so much more. You can go through the [PEP-8](https://www.python.org/dev/peps/pep-0008/) guide to get more guidance on how best to write your python code.