Full transcript
0:00Damn guys! You're here on day 6 too on 100 Days Of Code series
0:04This is what I wanted
0:05Today I'll tell you "What are variables"
0:07Variables are like containers just like you have in your kitchen
0:11In which you store lentils, flour & rice etc
0:13In Python Programming Language 'Variables' are just like those containers
0:16This analogy fits completely on the explanation of variables
0:18Let's suppose I've a container in my hand
0:21And let's suppose this container contains lentils
0:23And let's suppose that I replace those lentils with rice
0:26So basically I just changed the content of this container
0:29On the other hand, let's suppose if I take another container
0:33And in this container if I put some water and then I put some milk
0:37So I can change it's content
0:39This is exactly what happens in Python as well.
0:41That you people make containers and stores data in them.
0:45And this data is stored in the memory.
0:47It is stored in it, what you call 'RAM'
0:50What is 'Data Type' ?
0:51Just like a container can contain 'Liquid' 'Solid' 'Lentils' or 'Sugar'
0:57Even maybe there is something that is not even edible
1:00We have a lot of items
1:02For eg. liquid dish wash, that liquid is not edible
1:05So there are 'types' of everything
1:07Just like that there are 'Types' in Python which we refer as 'Data Types'
1:11Let's quickly move to the computer screen and learn "What exactly 'Data Types' are"
1:16And how they operates.
1:17Let's get started
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1:20[STARTING THEME]
1:27So exactly what are these 'Variables'. Let's check it out first.
1:30Variables are like containers, like I've told you already.
1:34But what type of container is this?
1:35This container is inside the memory
1:37Now, if you're confused about all this stuff.
1:39So move to the 'main.py' and have a look what am I doing here
1:45Then you'll get to know
1:46That how exactly you have to make 'Variables' in Python
1:50Why is it important to make 'Variables' in Python
1:53Look, if I write here "a = 1"
1:55I just need to do this. And then if I wrote "print(a)"
1:58I'm just basically commanding it to store 1 in my computer's memory or 'RAM'
2:04Store 1 in its actual memory
2:08And the place where it is stored
2:10Give that address to " a "
2:12Now this might sounds complex to you
2:15But whenever I use " a " after writing " a = 1"
2:19Which means whenever I want to refer its value
2:23I'll just print " a "
2:24Now you'll say I memorized " a = 1 " shouldn't I just directly print ( 1 )
2:27Why should I run this program?
2:29How about this? If I do this, so you made a program to save a number
2:34A number has been saved here and it is being printed
2:37So writing " a = 'whatever the number' " result in saving this number in " a "
2:41And by writing " print(a) " will result in " printing(a) "
2:43Can I write it like ' b = "Harry" ' ?
2:47The answer is...
2:48Yes I can
2:50But if I run this so, I'll only get this number printed
2:53And if I print(b)
2:56So you'll see that I'll get this "Harry" printed
2:59Which is great man!
3:00Because this is a different 'Data Type' and this one is a different 'Data Type'
3:03Now you'll say "Harry bhai when you wrote this number, you didn't use double-quotes(" ") "
3:09But when you wrote "Harry" why didn't you wrote it without double-quotes(" ")
3:12That is because it will throw an error.
3:14Now why will it throw an error?
3:15You'll ask "I can directly write 'Harry' "
3:18But.....
3:19We have to use double-quotes(" ") while representing an string 'Data Type'
3:24So that... It's possible that someone has written it like "Harry = 9"
3:29Now one can write "B = 'Harry' "
3:31Now how will Python know what you want to print "Harry" the 'String' or the '9'
3:35If I run this program so look, I'll get this '9' printed
3:38Look, 9 will be printed here
3:41It's possible that you literally want to print this "harry"
3:44But '9' will be printed
3:45That's why there are some rules in Python
3:47So let me remove it for now
3:48If I write ' b = "Harry" ' so directly the content of " b " will be printed
3:52As you all can see
3:54Now let me tell you what I've written for you
3:58So look. "What is 'Variable' " ?
3:59"Variable is like a container that holds data."
4:02"A container that holds data"
4:03Very similar to how our containers in kitchen holds sugar
4:07Just like containers used in your kitchen to hold salt, sugar etc
4:15Creating a variable is just like creating a placeholder in memory and assigning it some value.
4:18And here I've declared 4 types of 'Variables' 'a' 'b' 'c' & 'd'
4:23Now all these 4 'Variables' are of different kind
4:25Which means they are of different kind
4:27For eg. let's suppose you're a living being
4:31And there's a dog, he's also a living being
4:33And an ant is another living being
4:35But we all are different kind of living beings
4:38Same like that " a = 1 " is a different kind of 'Variable'
4:40" b = true " is a different kind of 'Variable'
4:42' c = "Harry" ' is of a different kind & " d = none " is a of different kind
4:46You're still watching this video on 1x
4:48Now if I've written " a = 1 "
4:51An integer has been stored in " a "
4:53When I wrote " b = true " so a Boolean has been stored in " b "
4:56' c = "Harry" ' result in storing a 'String'
4:58And " d = none " type
5:00.....
5:01When I wrote " d = none " so a 'None' type variable has been created here
5:05So these are 4 different kind of 'Data Types'
5:08What is 'Data Type' ?
5:09And why we need them?
5:10Look, I already have told you "Why we need 'Data Type' ? "
5:14That we need 'Data Type' so that we can store different type of values in memory
5:20OK! We know that
5:21'Data Type' specifies the type of value that a 'Variable' can store
5:26This is required in programming to perform operations
5:29For eg. Let's suppose if I write here...
5:32..." print(a + b)"
5:35So will it add "Harry" in it?
5:36Look it'll throw an error
5:38It is saying...
5:39...." You're trying to add an 'Integer' and a 'String' "
5:42" What are you trying to do? "
5:44Even if I decrease this number...
5:46"How can you add 'Harry' in '123' What do you want? What's your plan?"
5:50This is what Python is saying
5:54And we are telling Python that "We want to concatenate"
5:58So Python will say "How will I know that you don't want to concatenate or anything else, you're using the (+) sign"
6:06So that' why whenever we do (a+b) we keep this in mind that those 2 must be of same 'Data Type'
6:13So I'll do one thing...
6:15I'll create a variable with name (a1 = 9) and now if I add ( a & a1 )
6:19Then this operation will be performed successfully
6:22And look " 132 " will be printed here
6:24So this was very simple, you might already know this
6:27But we need 'Data Type' so that...
6:30...We can perform various operations without causing an error
6:34Without causing an error
6:35In python, we can print the type of any operator using type function:
6:39Suppose a variable has been created
6:40And I want to know its type
6:43So I can do that in this manner I can write "The type of a is... "
6:48And here by adding a comma(,) I can write " type(a) "
6:55So I've closed the bracket of ' type(a) '
6:58And now I've closed the bracket of this opening parenthesis
7:02Now if I run it, so look....
7:04" The type of a is <class 'Int'> "
7:06' a ' is an 'Integer'
7:08Let's see if we can do the same with 'b'
7:13I'll try to run it....
7:15And look, " The type of b is <class 'Str'> "
7:19And now if I do the same with the type(c)
7:25And look what's the type of 'c' is... There's nothing with name ( c )
7:28Let me try for 'a1'
7:30Or let me create 'c'
7:32What if I create all these 4 variables at once
7:37So there won't be any headache I now have all four variables (a, b, c & d)
7:41Now if I run it so the type of 'c' will be...
7:45It is saying " name 'a1' is not defined "
7:47I've written " print(a + a1)
7:49No problem, let me define 'a1' because I've to give this program to you
7:55So look I've written " a = 1 " So "1" "true" & "10" has been printed
7:59The type of a is <class 'int'> The type of b is <class 'bool'> & The type of c is <class 'str'>
8:03It has printed the type of all 3
8:05OK, Great! We got all the points till here
8:09Now let me tell you there are some built-in 'Data Types' in Python
8:12The first built-in 'Data Type' is 'Number'
8:16Which I already have told you
8:18'Int' 'Float' & 'Complex'
8:20Now if I change this 'a' to 1.1 from 1 Do you remember its type was 'Int'
8:26If I change 'a' to 1.1 so its type will be 'Float'
8:30And if I tweak it like....
8:32If I write it like "8+2i" so it'll become a 'Complex' number
8:38Actually to create a 'Complex' number I've to do something like this
8:42I'll write " 8,2 "
8:44And when I'll write this so a complex number will be created
8:47And look, a complex number has been created with name "8 + 2j "
8:53If you don't know about 'Complex' number is So that's totally fine
8:56I don't expect you to know 'Complex' numbers
8:58But I just want to tell that you can also create 'Complex' number in Python
9:02Basically these are the numbers with real part & imaginary part if you've studied 'Complex' numbers in +2, Good for you
9:08But if you haven't studied this in +1 or +2 BTW it's the topic of +1
9:12But different boards have different syllabuses
9:17So some students studies this in +1 and some in +2
9:19Anyways....
9:19It is showing its type as 'Complex' I just want to show you that..
9:23It has become a 'Complex' number
9:25So look I've written that the numbers can be of 'Integer' type or 'Floating Point Number'
9:29Or 'Complex' type
9:30And along with that if we talk about 'String'
9:32"Hello World!!!", "Python Programming" enclosed in double-quotes(" ")...
9:37...These are of 'String' type
9:39Now if I talk about 'Boolean' data, so they can either be True or False
9:43Now why we'd like to use them?
9:46Let's suppose you write a function
9:48And you want to return the driving test as 'Pass' or 'Fail'
9:52If you don't know what functions are.. So let me tell you
9:55Let's suppose if you want to tell me that if I'm able to drive or not
9:59So you can just give a minor information In type of 'Yes' or 'No'
10:04So this is the work 'Boolean' perform
10:07You don't directly have to say "Yes! You can drive"
10:10You don't need to give all these information
10:13You can either say 'Yes' or 'No'
10:14'Yes' means 'True' or else 'False'
10:17Just like 'String' contains a lot of values like 'HARRY' and many other characters
10:22But if you want to tell me, if I'm able to drive or not
10:25So you can say 'Yes' or 'No'
10:28And you should be good
10:30So this is Boolean 'Data Type'
10:32Why we use that?
10:34And when we should use that? We'll talk this later
10:37And then comes the 'Sequence' Data
10:39I'll now talk about 'List & Tuples'
10:41And there's no need for us to dive deep in 'List & Tuples'
10:44I just want to tell you that there's something named 'List & Tuples'
10:47What is 'List' ? List is an ordered collection of 'Data Types'
10:50And we'll study this later so I won't tell much about that right now
10:53And if you want to know about 'List'
10:56Hold your horses man!
10:58I'll tell you about 'List'
11:01Now what is 'List' ? List is basically a collection of different data elements
11:06Elements which can be of different kinds For eg. This is a 'Integer' and this is a 'Float'
11:09Added a list in a list and another list
11:12So basically 'List' is a List of items which can be of different 'Data Types'
11:16For now I'll only explain this, not much
11:19And we can make changes in 'List'
11:21What is 'Tuple'?
11:22Exactly the same thing as 'List' I'm telling you in a very easy manner
11:25Exactly the same thing...
11:27...Except they are immutable. Immutable means they cannot be changed
11:31Now people confuses a lot in mutable & immutable
11:35I'm telling you with my experience many people says
11:38"Bro we are not able to remember whether we can change mutable or immutable"
11:45We've a problem with that
11:46Let me tell you how you can remember
11:49Let's suppose if it is mutable
11:51You might have studied about 'Mutation'
11:53'Mutation' basically means the occurrence of changes
11:56For eg. There's a theory which explains that in the early ages Humans used to have tails
12:00Then there were mutations, after that the tail of the humans was lost
12:05This is what scientists say
12:07I'm not teaching Biology here I'm just telling you that 'Mutation' means the occurrence of changes
12:13If you've studied Genetic Algorithm
12:16If you've studies even a little bit of Biology in Class 10th or 9th. Come on we all did
12:21'Mutation' means changes
12:23That we used to be Monkey at first
12:25Then we evaluated to Humans This is called Mutations
12:28So 'Mutable' means changes can be made
12:31'Immutable' means changes cannot be made
12:34This is how you can remember
12:36It's the easy way to remember
12:37It's possible that you remember it easily
12:38And after listening to me you can say "Come on bro! I remember it easily"
12:42I was just telling this for the people who hardly remembers it
12:45Now look,
12:47I've made a list "List the collection of items"
12:50And the 'Tuple' is also the same "List the collection of items"
12:52Except the fact that you cannot change it
12:56But if you try to do so...
12:58So it'll throw an error
12:59And "How can we change it" and all the other stuff we'll leave that for the video related to 'Tuple'
13:04I won't tell you that right now
13:05Then there comes another 'Data Type' "Mapped data: Dict"
13:09What's this? You must have a dictionary at home
13:11No?
13:12No problem! But you definitely know what dictionary is.
13:15Dictionary is the collection of key-value pairs
13:19You want to know the meaning of "Abandon"
13:21'Abandon' is a key and there'll be its value in dictionary
13:24You want to now the meaning of 'Food'
13:26'Food' is a key there'll be its value in dictionary
13:29We all know what 'Food' is
13:31Now another one... Let's suppose you want to find the meaning of...
13:34I don't remember any complex word right now. Let's say 'Mutable' you want to see it's meaning
13:37There'll be its value, meaning of "Mutable" will be written in dictionary
13:41So these are key-value pairs
13:43In form of Key-Value pairs, I can store anything
13:47In form of Key-Value pairs, I can also store...
13:50That...
13:51Marks of every student
13:53"Name of the student"
13:54And "His/Her marks"
13:56We can store this information too
13:59I just want to tell you
14:00Now let's move here...
14:02And look..
14:03I've written "dict1 ={"name":"Sakshi", "age":20, "canVote":True}
14:07So it'll print like this... Let me show you
14:09Name is 'Sakshi'
14:10Age is 20 canVote is 'True'
14:12I'll tell more about dictionary in the upcoming videos
14:14For now just understand that dictionary is a mapped data
14:17We have mapped one thing from another
14:19For eg. Name = Sakshi Marks = .....
14:22Whether she can vote or not...
14:24And if she is a good girl or not...
14:27How's she at her studies
14:29How much she scores...
14:31About her behaviour
14:35Is she a disciplinarian or not
14:37Are you getting my point? You just have to add these here
14:40And...
14:42Your dictionary will be ready
14:43So I hope you've understood the topics 'Tuple' 'List' & 'Dictionary'
14:47Now I'd like to say something
14:49This may blow your mind
14:53Your mind will be blown after listening to this
14:55May be not! May be
14:57But you'll put your thinking cap on
15:00Everything in Python is an 'Object'
15:03Yes! Everything
15:04'Dictionary' is an object
15:06If you create a 'Dictionary', so it is an object
15:09If you create a 'Boolean', so it is an object
15:11'Integer' is an object of class 'Int'
15:14That's why when we printed it, we saw that...
15:19Look here, at the top
15:22" The type of a is <class 'complex' "
15:24So why is it referring it as 'Class'
15:26It's the 'Object' of this class
15:28Now you'll say "What is 'Class'? What are you saying 'Class' 'Object'....
15:33I'll explain everything in the upcoming videos
15:35I'll explain everything when we'll move to the object oriented programming
15:38For now just remember my words...
15:40"Everything in Python is an 'Object' "
15:42Just remember this
15:45But if you'll remember this thing so I'll remind you
15:48But for now just forget this
15:50I didn't say a word about this to you
15:54When we'll be on the video of "Classes & Objects" then you must remember this...
15:57That I told you "Everything in Python is an 'Object' "
15:59I'll explain this in that video
16:01For now just grasp the concept of 'Data Type'
16:03There are different kind of 'Data Type'
16:05Study this efficiently
16:08That's it for this video and I hope you had fun in it
16:11And if you haven't accessed the Python Play-list yet
16:13So make sure to access it
16:15Bookmark it by clicking here just like me and save it by clicking here