DEV Community: Abu zubaer

Lists/array

Abu zubaer — Sun, 28 Feb 2021 15:10:46 +0000

I am going to writing about the most used data structure list/array's. if you don't know what is a data structure, don't worry, I will explain.

we know that on the computer we just play with data. we can not think without data. we can not do anything without data.
watching movie? these are data. text is a data, image is data even number or string are also a data.

The programmer's duty is to solve the problem by using data. to easily solve the problem programmers need to structure their data in many ways.
list/array one of them.

previously we had known, how to assign data in a variable.
in python language we assign data

like this.
suppose we have a country variable and have to assign all the city's names under the country. what we're gonna do.

in this situation, we have to use the list/array's structure.

example:
country = ['city1','city2','city3'] --> this is list's.

you can see in the picture the index starts at 0.
remember this in the list count from zero 0.
if you want to print city1 from the country list. you should define index number 0.

print(country[0])

the result will print city1.

there have some methods on the list.
these are --> append,pop,reverse,sort etc.
if you want to add another city to the country list you can do this by using the append method.
example:
country.append('city4')
print(country)

city4 will be added to the last of the country list.

if you want to delete the last index of the country you can do this by using the pop() method.
example:
country.pop()
print(country)

in python language, there have many list methods. and these are easy to use. that's why I don't explain all.
go google and search to write list method in python. you will get lots of resources.

whatever, don't forget to do googling...

this is for today.
thanks for reading.

if else statement in python

Abu zubaer — Thu, 25 Feb 2021 15:17:14 +0000

Let's talk about the if-else statement.
In programming, mostly use conditional statement.
you can't think to solve any problem without a conditional statement.

you can see the example of the if-else condition in the picture.
if (it's raining)
then I will take the umbrella
else
not

this is so easy. isn't it?

now I m gonna show you. that how to write a conditional statement in python language. before that, let's look at a flowchart of a conditional statement.

In that flowchart, you can clearly see, if the condition(its rating) is true then he will take an umbrella if the condition is not true then he will not take an umbrella.

Syntax:
if condition:
print('if the statement is true then print me')
else:
print('if that condition was not true then print me')

this is the conditional syntax in python.
remember, you have must input a colon after a condition, and should execute in the next line.
otherwise, you can get an error.

this is the right syntax. there has no error.
">" this is the 'greater than" operator.
this operator has to check if their age is greater than 18 or not.
in a programming language, there have many mathematical operators.
don't worry about this. I am gonna talk about that.
">" --this is "greater than operator".
"<" -- this is "smaller than operator".
"=" -- this assignment operator.
"==" --this is equal to operator.
"%" --this is the modulus operator or reminder.

that's it for today.
The next day I am gonna post about the nested loop.
and thanks for reading this.
happy coding.

Type error in python

Abu zubaer — Wed, 24 Feb 2021 18:23:24 +0000

in python, You can not concatenate two types of data.
suppose you are want to concatenate an integer value to a string value.
string = "hello earth"
number = 404
print(string + 'how are you' + 'your server error number is' + number)
the result will be a type error

now, you think about how to concatenate different types of data !!
in python, have a simple way to solve this problem.
you can solve this problem by converting the data.
suppose, you have two types of data number and string
number = 14644
string = 'anything'
convert_number_as_a_string = str(number) //converting number to string by str method.
print('hey number' + number + 'hey string' + string) //wow it's work now

but I think this is the weird way.
there has another easiest way to solve this problem.
f-string can solve this problem

number = 11544
string = 'anything'
result = f"its number {number}. its string {string}"
print(result)

woow..it's work.
can't believe it?
just open your code editor or ide and try this / practicing this.

this is my first post in dev. pardon me, if I did any mistake.
note -- English is not my native language so normally you've could get a grammatical error.

tanks for reading..